Mechanical Code Sbs

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MECHANICAL CODE – CHAPTER 1 – ADMINISTRATION

SEE HIGHLIGHTS ABOVE

MECHANICAL CODE – CHAPTER 2 – DEFINITIONS

Section MC-201. General. This section describes the meaning of the words and terms

contained in this chapter. For the purposes of this code, these terms shall have the

meanings indicated in this chapter. The current Building Code Sections 27-229 and 230have similar provisions. Section 27-230 of the current Building Code also states that the

definitions that appear in the Building Code Reference Standards shall apply to the

provisions of those Reference Standards only.

This section states that words used in the present tense include the future, words used in

the masculine gender include the feminine and neuter gender, singular numbers includes

the plural, and vice versa. Section 27-231 of the current Building Code has similar

statements of interchangeability. This section also states that when a word or term thatappears in this proposed code is not defined in this chapter, other references may be used

to find its definition, such as other NYC Construction Codes and applicable standards.The current Building Code has similar provisions.

The current NYC Building Code states in Section 27-229 that where terms are notdefined in the code, they shall have their “ordinarily accepted meanings” or such as the

context may apply.

This section also states that when terms are not defined in the proposed code or other

references, their “ordinarily accepted meanings” shall be used.

27-229, 27-230, 27-231

Section MC-202. General Definitions. This section provides the meanings for terms to be used throughout the proposed code. The current Building Code does not provide

meanings for the majority of the terms introduced in this section.

27-232

MECHANICAL CODE – CHAPTER 3 – GENERAL REGULATIONS

Section MC–301. General. This section sets the parameters for applying the proposed

New York City Mechanical Code, setting its scope as the approval and installation of allequipment and appliances that comprise parts of building mechanical systems. It

references the Energy Conservation Construction Code of New York State and the New

York City Fuel Gas Code for related issues. The proposed code requires that equipment

regulated by the code be listed by nationally recognized testing laboratories and belabeled according to the listing terms. The code further requires that structural, plumbing,

electrical, and fuel issues surrounding the systems and equipment regulated by the code


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conform to their respective construction codes, and that in flood hazard areas, equipment

be installed consistent with design flood conditions. Rodent proofing in the proposedcode is also similarly covered in the Multiple Dwelling Law. These provisions are

consistent with those in the current Building Code, except that the Building Code requires

acceptance of materials by the Commissioner of Buildings (through the MEA Division)

before equipment can be used. 27-130, 27-131, 27-288, 27-569(b), 27-771, MDL 80(6),RS 4-5

Section MC–302. Protection of Structure. This section regulates the penetration ornotching of structural and non-structural members for the installation of mechanical

systems and the penetration of fire-rated elements for such installations. Neither the

structural integrity nor the required fire resistance of structural and nonstructuralmembers and assemblies may be compromised. Empirical specifications have been added

for both wood and steel studs which are not covered in the current Building Code. Other

than these provisions, any penetration or notching must be designed by a registered

design professional and the required fire resistance must be maintained. The current

Building Code generally requires adequacy of structural design. 27-327(a), 27-585, 27-596

Section MC–303. Equipment and Appliance Location. This section establishes general

parameters for the location of equipment and appliances, for which additional specific

requirements may apply under other sections or under conditions set by listinglaboratories or the Department of Buildings. In general, equipment and appliances may

not be located in hazardous or outdoor locations, or in closets or alcoves, unless they are

listed and approved for same. Fuel-fired equipment and appliances are not permitted inspecified rooms, nor are they permitted to obtain combustion air from these rooms, with

some exceptions and are limited by the provisions of the Energy ConservationConstruction Code of New York State. When appliances or equipment are located in a pit

or excavation, equipment or appliances may not come into contact with soil. The

proposed code specifies both clearances and concrete/masonry construction for this typeof installation. The current Building Code has similar provisions. Mechanical systems

are not permitted in elevator shafts, and there is no comparable provision in the current

Building Code.

27-792, 27-805, 27-806, 27-817, 27-819, 27-820, RS 13-1, RS 14-15

Section MC–304. Installation. This section requires that equipment and appliances be

installed in accordance with the manufacturer’s instructions, terms and conditions of theaccepted listing agency, and this code. In the event of a conflict between the proposed

code and either the manufacturer’s instructions or the terms and conditions of an accepted

listing agency, the proposed code shall govern. Equipment in hazardous locations andgarages shall have an elevated ignition source. Natural ventilation requirements are stated

for louvers that are similar to those of the current Building Code. The code establishes

minimum or maximum heights and clearances for ignition and fuel-burning equipment,

clearances to combustible construction, clearances above grade, and guardrail criteriawhere required. The code requires that equipment or appliances serving areas of a

building remote from their location be identified as serving such area(s). This section is


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consistent with the current Building Code.27-419(b), 27-792, 27-804, 27-805, RS 13-1,

RS 14-1, RS 14-15, RS 14-17

Section MC–305. Piping Support. This section requires that piping support hangers and

other devices be of materials that can sustain static and dynamic loads and do not induce

galvanic action. The code provides that piping supports shall be attached to the building.Rules for spacing are given. Non-ferrous piping that passes through studs or joists must

be protected by steel shield plates. No comparable provisions exist in the current Building

Code. Section MC–306. Access and Service Space. Minimum clearances for themaintenance and replacement of equipment and appliances are established in this section.

In general, clearances must be sufficient to permit inspection, service, repair, or

replacement of the equipment without compromising either permanent constructionincluding other equipment and appliances) or required fire resistance of any permanent

construction. The section addresses clearances around central furnaces, appliances in

rooms and attics, and their requisite access passageways and level service spaces. It

requires minimal electrical lighting in attics. It also addresses appliances located under

floors, requiring electrically lit passageways and service spaces, and concrete or masonrywalls and four-inch curbs around passageways and service spaces more than 12 inches

below grade. Finally, it addresses equipment and appliances mounted on roofs or elevatedstructures greater than 16 feet above grade, setting minimum standards for permanent

access ladders and landings, catwalks, and for platforms on roofs with a slope of 25% or

greater.

The current Building Code deals more generally with access and service space

requirements, and so the adoption of the proposed code will result in added safety provisions.

27-776, 27-782, 27-792, 27-805, RS 13-1, RS 14-1, RS 14-15

Section MC–307. Condensate Disposal. This section sets forth the requirements fordisposal of condensate produced both as a byproduct of fuel-burning appliances and by

evaporators and cooling coils. The code provides that condensate shall not be discharged

to a public street, alley, or otherwise create a nuisance. This section of the code defines

acceptable materials, minimum sizes, and slopes for condensate piping. It requires asecondary drainage system in some cases and trapping of condensate where indicated by

the manufacturer of the equipment or appliance. Unlike the proposed code, the current

Building Code does not permit the use of plastic piping for condensate piping (except forresidential buildings of three stories or less), and also is much less detailed in its

requirements in that it provides only that condensation shall not cause deterioration of a

chimney or vent. Both window and wall air-conditioning units are exempt from therequirements of this section, and the current Building Code does not mention this point.

27-854, RS 16

Section MC–308. Clearance Reduction. Clearance requirements for fire safety areestablished for hot or heat-producing equipment in subsequent sections of the code;

however, both the proposed code and the current Building Code allow for reduced


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clearances provided positive barriers are introduced. The language in the current Building

Code states that clearance reduction is permitted when exposed combustible constructionis protected with noncombustible material. The clearance reductions in the proposed code

are greater than those in the current Building Code.

Reduced clearances are not permitted for masonry chimneys, chimney connector pass-

throughs, masonry fireplaces, or kitchen exhaust ducts enclosed in a shaft, and are limitedto a minimum clearance of 12 inches around solid fuel-burning appliances. 27-806, RS

14-16

Section MC–309. Temperature Control. The proposed code states that interior spaces

intended for human occupancy shall have space-heating systems that can maintain a

minimum temperature of 68ºF at a point 3 feet above the floor on a design heating day.The current Building Code requires that a minimum temperature of 70ºF be maintained in

habitable rooms, and provides additional minimum temperatures for other types of

rooms, mostly for industrial use. 27-740

Section MC–310. Explosion Control. The proposed code states that structures involvingexplosion hazards shall be provided with explosion control systems in accordance with

Fire Department regulations. The current Building Code also refers to Fire Departmentregulations for explosion control and, therefore, the codes have equal provisions.

27-401

Section MC–311. Smoke and Heat Vents. This section of the code requires smoke and

heat vents in the roofs of one-story buildings in accordance with Fire Departmentregulations. The present Building Code is much more detailed in that it gives venting

specifications and provides venting requirements for different types of buildings.27-353

Section MC–312. Heating and Cooling Load Calculations. Under the proposed code,heating and cooling system design loads for the purpose of sizing systems, appliances,

and equipment shall be calculated in accordance with the requirements of the ASHRAE

Handbook, or in accordance with Chapter 3 of the Energy Conservation Construction

Code of New York State. These codes call for an outdoor design temperature of 13oF for New York City. The current Building Code calls for using an outdoor temperature of 5oF

and a wind velocity of 15 mph as the design criteria for sizing the heating system

equipment. This results in larger heating loads and larger equipment in comparison to the proposed code design criteria. RS 13

MECHANICAL CODE – CHAPTER 4 – VENTILATION

Section MC-401. General. This section describes the scope of ventilation design

requirements for spaces within a building intended to be occupied. It does not include the

requirements for a smoke control system; those are included in Chapter 5. This sectionfurther requires that all occupied spaces be ventilated either by natural or mechanical

means or a combination of both, while occupied. It specifically addresses the


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requirements for exit enclosure ventilation, outside air exhaust and intake opening

locations, natural and mechanical ventilation requirements including ventilation ofenclosed parking garages, mechanical ventilation systems control, and ventilation of

uninhabited spaces including crawl spaces and attics.

The requirements mandated in this section for minimum distances between exhaust andintake openings in the same building and in other buildings, lot lines, combustible

construction, grade level and other intake and exhaust openings including the ones in the

flood hazard areas are comparable with the requirements in the current Building Code.The requirements for protecting the outdoor termination points of intake and exhaust

openings by screens, louvers or grilles and for handling stationary local sources

producing air-borne particulates, heat, odor, fumes, vapors, smoke or gases, etc., whichare injurious to health, are also addressed in this section. The current Building Code

addresses similar issues in several different subchapters throughout the proposed code.

27-745, 27-752 thru 27-767; RS 13-1:2-2.1

Section MC-402. Natural Ventilation. This section merely cross-references Chapter 12of the proposed Building Code.

Minimum requirements for dimensions of openings (doors, windows, louvers, grills, etc.)

to provide natural ventilation are specified in Chapter 12.

The proposed code allows for spaces to be ventilated through an adjoining space,

provided certain minimum requirements are met. The current code does not cover this

issue for occupied spaces, but prohibits ventilation through adjoining spaces in non-residential applications.

The provisions for ventilation of residential bathrooms and kitchens mandated in Chapter

12 are generally similar to the current Building Code, including reference to the Housing

Maintenance Code (HMC) and Multiple Dwelling Law (MDL) for more details. The provisions governing openings on to yards and courts are generally similar in both codes.

The proposed code includes standards for ventilating attic spaces, whereas the current

code does not address this issue.

27-745 thru 27-751

Section MC-403. Mechanical Ventilation. This section establishes certain minimumrequirements with regards to mechanical ventilation of occupied spaces. It addresses the

required quantities of supply air and return or exhaust air for various spaces of occupied

buildings in a tabular form, and also addresses the issue of where and how much quantityof recirculated air (transfer air) is permitted for various sections (parts) of an occupied

building space. The required ventilation rates (the minimum outdoor airflow rates) are

specified in tables based on the type of occupancy and size, and the occupant load or

other parameters as stated in the tables. Where both the outdoor air and the recirculatedair are combined to meet the make-up air requirements, certain minimum quantity of

outdoor (fresh) air must be provided as specified in the code tables.


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This section differs from the current code in the method of determining the minimumventilation rates and outdoor air requirements. The current code uses a ventilation index

based on the volume of an occupied space, whereas this section of the proposed code

requires the ventilation rates to be calculated based on certain formulae for individual as

well as common ventilation systems.

27-752 thru 27-754

Section MC-404. Enclosed Parking Garages. This section establishes certain minimum

requirements for ventilation of enclosed parking garages. Mechanical ventilation systems

for such garages are not required to operate continuously where the system is arranged tooperate automatically upon detection of concentration of carbon monoxide (CO) gas of

25 parts per million (ppm) by approved automatic CO detection devices. A minimum

ventilation rate of 0.05 cfm/sq. ft. of the garage floor area is required, and any system

must be sized for a minimum ventilation rate of 1.5 cfm/sq. ft. of floor area. Connecting

offices, waiting rooms, ticket booths, etc. which are accessories to a public garage shall be maintained at a positive pressure, and shall be ventilated at a minimum rate of one cfm

per square foot of the floor area.

The current Building Code has similar requirements with the following variations which

are less stringent compared to the requirements in the proposed code. The currentBuilding Code calls for automatically operated mechanical ventilation systems for

enclosed parking garages to maintain an average CO concentration not to exceed 100

ppm compared to 25 ppm CO concentration under the proposed code. Also the currentcode requires any mechanical ventilation system to be sized for not less than one cfm per

square foot of the floor area of a garage compared to a minimum ventilation rate of 1.5cfm/sq. ft. under the proposed code.

27-456

Section MC-405. System Control. This section establishes the design criteria for manual

and automatic control of mechanical ventilation systems and the associated air-

conditioning systems for occupied spaces. Each air distribution system is required to haveat least one manually operable means to stop the operation of supply, return, and exhaust

fans in an emergency.

In addition, this section requires that in office buildings with a height of 75 feet or more

where a system serves multiple floors a manual control for individually operating each air

supply and exhaust fan from the fire command station as well as the room containing theair handling fans shall be provided. This section also calls for providing manual controls

for operating individually or in groups each remote controlled reversible fire shutter or

each smoke damper in accordance with the provision of the current Building Code. These

remote manual controls are to be located at the fire command station.

27-777.1; RS 13-1: 4-2, 4-3, 4-4; RS 13-4:4-3


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Section MC-406. Ventilation of Uninhabited Spaces. This section requires thatuninhabited spaces, such as crawl spaces and attics, be ventilated either by natural

ventilation or mechanical ventilation using exhaust and supply air systems. Natural

ventilation, if used, should meet the requirements of the proposed NYC Building Code.

If mechanical ventilation is used, then the exhaust rate should not be less than 0.02 cfm per square foot of horizontal floor area of the crawl space or attic. The mechanical

ventilation system should be automatically controlled to operate when the relative

humidity in the space exceeds 60 percent.

The current Building Code addresses natural ventilation requirements of crawl spaces,

but does not address uninhabited spaces such as attics. The current Building Code makesno mention of any mechanical ventilation system application for crawl spaces or attics.

27-762

Section MC-407. Ventilation of Non-production Chemical Laboratories. This sectionreferences NFPA 45 for the requirements of mechanical ventilation systems serving non-

production chemical laboratories that are in compliance with the hazardous quantitylimitations of Section 419 of the New York City Building Code. This section modifies

the requirements of NFPA 45 by prohibiting the use of ducts constructed of combustible

materials. The equivalent requirements do not appear in the current code.

MECHANICAL CODE – CHAPTER 5 – EXHAUST SYSTEMS

Section MC–501. General. This section sets forth the scope of the chapter for standards

of exhaust systems. It provides that air shall be exhausted so that it will not create anuisance and cannot be drawn in to an air intake system. The code also provides that an

exhausted space be maintained at a neutral or negative pressure, and that bath, toilet, and

similar rooms having exhaust systems be independent. These requirements are similar tothose in the current Building Code.

27-759(c)(2), 27-771, 27-776, RS 13-1

Section MC–502. Required Systems. This section lists the types of industrial equipment

that shall be exhausted, and provides that the system be designed so that contaminants do

not spread to other parts of a building. The code provides that the air intake to the exhaustsystem be located near the source and, in the case of fuel dispensing, that the inlet be no

more than 18 inches above the floor. The areas to be exhausted include aircraft, battery-

charging areas, dry cleaning plants, cleaning equipment, spray booths, projection rooms,tanks, areas containing various hazardous materials, gas-generating facilities, and

garages. The proposed code is highly detailed and gives limitations for hydrogen

concentration, ventilation rates for various systems, required air velocities, and

termination points. For example, the proposed code states that rooms containingflammable liquids shall be exhausted at a minimum rate of 1 cfm/sq. ft. of area. In

addition, the proposed code requires that spray booths have a minimum of 100 fpm of air


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velocity. In contrast, the current Building Code requires rooms that are used for storage

of flammable equipment using mechanical ventilation to be exhausted at the rate of 2 airchanges per hour. The requirements for spray booths are identical to those in the current

Building Code. For dry cleaning establishments, the proposed code refers to Federal

Regulations, while the current Building Code states that 10 air changes per hour are

required for moderate hazard plants, and that 4 air changes per hour are required for lowhazard plants. For garages, the proposed code refers to Chapter 4 of the proposed code

for exhaust requirements of 1.5 cfm/sq.ft., and the current Building Code generally

provides for a rate of 1 cfm/sq. ft. for garage exhaust. The proposed code is somewhatmore stringent. For non-residential buildings, both codes provide for a 16 gauge thickness

for kitchen exhaust ducts, and a thinner 18 gauge for residential buildings. However, the

current Building Code allows for an even thinner 20 gauge duct thickness for one andtwo-family dwellings when stainless steel is used, unlike the proposed code, which

requires 18 gauge for similar circumstances. Since the thickness of the material decreases

as the gauge increases, the current Building Code is less restrictive because it allows for a

thinner and cheaper material for stainless steel ductwork for one and two-family

dwellings. 27-405, 27-410, 27-428, 27-446, 27-453, 27-456, 27-478, 27-766, RS 13-1,RS 13-2, RS 13-3, RS 13-5

Section MC–503. Motors and Fans. This section requires that motors and fans be

approved for the environments and applications for which they are used, including those

used in areas containing flammable vapors or dust. Fans installed under these conditionsmust be manually controlled from a remote location. Fans in such areas shall be

interlocked with the ventilation system. Motors and fans shall be accessible for

servicing. Fans and casings must be of material approved for their function. Motors andfans used to exhaust explosive or flammable vapors, fumes, or dust must have an

identification plate stating the ventilation rate for the system. Fans that exhaust corrosivefumes shall be of corrosion-resistant materials. Fans that exhaust noxious, toxic, hot

vapor, or grease-laden air shall be placed as close to the terminus as possible. None of

these provisions in the proposed code are dealt with in the current Building Code.However, the Building Code provides similar provisions for vibration isolation, and

provides for clearances for fan equipment. 27-770(b)(4), RS 13-1

Section MC–504. Clothes Dryer Exhaust. Clothes dryers must be independentlyexhausted to the outside, and shall comply with the manufacturer’s instructions. Clothes

dryer exhaust ducts shall not be connected to a vent connector, vent, or chimney, and may

not pass through fire-rated construction except with restrictions to maintain the fireresistance rating. Fire dampers are prohibited, as well as screens, sheet metal screws or

other obstructions to the airflow. Backdraft dampers at the outdoor terminal are required.

Make-up air is required if the exhaust rate is more than 200 cfm. The section covers bothcommercial and residential clothes dryers. Ducts for domestic clothes dryers shall be

properly supported and have a smooth finish. The current Building code generally states

that exhaust should not create a nuisance, fire, or health hazard. The Reference Standards

state the required exhaust location, along with materials of construction for ducts, i.e.,iron, steel, copper, concrete, masonry, or clay tile.


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27-776, 27-880, RS 13-1, RS 14, RS 14-6, RS 15-2

Section MC–505. Domestic Kitchen Exhaust Equipment. With certain exceptions,

residential appliances equipped with downdraft exhaust shall be discharged to the outside

through ducts constructed of galvanized steel, stainless steel, aluminum, or copper. These

ducts shall be air tight, equipped with smooth inner walls and be equipped with a backdraft damper (505.1). The materials of construction provided in the current Building

Code are the same, except that the current Building Code allows for iron, concrete,

masonry, and clay tile ducts, in addition to the materials listed above. A major change between the codes is that the proposed code allows the use of Schedule 40 PVC plastic

pipe under certain circumstances, while the current Building Code does not allow the use

of plastic pipe. 27-880, 27-881, RS 13-1, RS 13-2, RS 13-3, RS 15-2

Section MC–506. Commercial Kitchen Hood Ventilation System Ducts and Exhaust

Equipment. The proposed code provides that ducts shall be designed for the type of

service installed for and shall terminate at the outside of the building. The proposed code

states that exterior ducts shall be constructed of stainless steel with a minimum thicknessof 0.043 inches, and shall be adequately supported on the exterior. Clearance

requirements are such that a minimum of 24 inches shall be provided to any door,window, or exit. On the other hand, , the current Building Code requires that duct

thickness conform to good industry practice, and further allows the materials of

construction as stated in Section 505 above. The proposed code states that Type I hoodsshall be independent of other exhaust systems, except under certain conditions. Both duct

joint types and duct to hood joints are specified. Both codes allow for flexible

connections. The proposed code provides for vibration isolation as does the currentBuilding Code. The proposed code has extensive provisions for grease duct systems,

providing for the method of construction and clearance specifications. It also providesfor access openings, as does the current Building Code, and states that grease shall be

prevented from accumulating in ductwork. The proposed code provides that fan discharge

will not impinge on the roof or other adjacent structures, and provides clearance andtermination locations. This extensive section is more detailed than the current Building

Code. 27-770, RS 13-1, RS 13-3

Section MC–507. Commercial Kitchen Hoods. This section requires hoods oncommercial cooking appliances. The code specifies the materials of construction along

with hood thickness, and provides that the hoods be supported adequately. The code

specifies clearances for grease filters. It states the minimum net airflow for hoodsdepending on hood type and gives ventilation requirements in cfm for various types of

appliances. The code provides that filters be serviced properly. The current Building

Code refers to a modified version of ANSI/NFPA 96 for removal of smoke and vaporsfrom commercial cooking equipment. RS 13-3

Section MC–508. Commercial Kitchen Makeup Air. This section requires that an

equal amount of makeup air be supplied as the amount of air exhausted. In general, atemperature differential of not more than 10ºF shall be maintained, except for makeup air

that is part of an air-conditioning system, or makeup air that does not decrease the


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comfort conditions in the room. On the other hand, the current Building Code states that

replacement air shall be provided to prevent a negative pressure in the room of not lessthan 0.02 inches of w.c. While the proposed code differs from the current code, it reflects

national standards and industry practice. RS 13-3

Section MC–509. Fire Suppression Systems. The proposed code requires that a firesuppression system be installed when Type I hoods are required. Fire suppression

systems required for cooking equipment are covered in the current Building Code, in that

it lists types of equipment and requires portable fire extinguishers. Operatingrequirements are given in detail, and include means of activation along with automatic

shut-off. RS 13-3

Section MC–510. Hazardous Exhaust Systems. This section regulates the design and

construction of hazardous exhaust duct systems. The proposed code provides that a dust

collection system to be provided for lumber yards and woodworking facilities where

combustible dust is produced. It requires makeup air equal to the amount of air exhausted

by the duct system, and provides that the system be independent. Penetrations ofstructural elements shall be enclosed in a fire-resistance rated shaft. The proposed code

includes requirements for a fire suppression system, and provides minimum thicknessrequirements, along with combustible clearances. Air recirculation is not permitted. The

current Building Code does not specifically regulate hazardous exhaust systems, but does

prohibit the recirculation of air containing hazardous materials.RS 13-1

Section MC–511. Dust, Stock and Refuse Conveying Systems. The proposed codestates that cyclone separators shall be constructed of noncombustible material, and

provides that exhaust shall be discharged to the outside. The discharge may not be pipedinto another appliance. The code gives the methodology for spark protection and

explosion relief vents. The location of ducts and other outlets are given. The current

Building Code provides only for fire protection for ducts passing through floors27-987(c)

Section MC–512. Subslab Soil Exhaust Systems. This section states the materials that

may be used for ducts, including cast iron, galvanized steel, brass or copper pipe, and plastic pipe. Slope and termination requirements are given, and the code provides that

ducts shall be marked. There is no equivalent provision in the current Building Code..

Section MC–513. Smoke Control Systems. This section establishes the minimum

requirements for the design, installation and acceptance testing of smoke control systems

that are intended to provide a tenable environment for the evacuation or relocation ofoccupants. The current code does not devote an exclusive section to smoke control

systems and, furthermore, applies the nomenclature “smoke control” to systems for

controlling smoke within ventilation systems, not within building spaces. The

components of smoke control systems as described by this section, including ventilation,exhaust, smoke barriers, and draft curtains are addressed in different subchapters


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throughout the current code to a substantially equivalent extent, although the details may

not necessarily correlate exactly with this section.

This section provides the requirements for smoke proof enclosures for internal stairs,

including construction specifications and ventilation alternatives. The equivalent does not

appear in the current code.

This section provides the requirements for underground building smoke exhaust systems.

The equivalent does not appear in the current code.

27-353, 27-353.3, 27-396.4, 27-777.1(a)(6), RS 13-1, RS 5-11, RS 5-18, RS 17-3, RS 17-

5

Section MC–514. Energy Recovery Ventilation Systems. This section sets the

requirements for energy recovery ventilation systems, and provides that the systems shall

comply with the provisions of the Energy Conservation Construction Code of New York

State. This section allows the use of energy recovery ventilation systems except indesignated locations, such as hazardous exhaust, dust, stock, and refuse systems, smoke

control systems, and kitchen or dryer exhaust systems. It further provides that accessshall be maintained. There is no comparable provision in the current Building Code.

Section MC–515. Post-Fire Smoke Purge Systems. This section is a duplicate ofSection 912 of the proposed Building Code.

MECHANICAL CODE – CHAPTER 6 – DUCT SYSTEMS

Section MC-601. General. This section establishes the scope and governs duct systemsdesign for movement of air for heating, ventilating, air conditioning and exhaust systems

except as required by Chapters 5 and 7 of this code. The requirements for the installation

of supply, return and exhaust air systems are included in this chapter. It also addresses thestructural integrity and fire-safety aspects of duct system design. However, it does not

govern parameters for duct system design such as duct sizing, efficiency, occupants

comport, etc. Air movement in exit access corridors and in ceiling plenums above exit

access corridors is treated similarly to the provisions in the current code. RS 13-1

Section MC-602. Plenums. Except in one- and two-family residences, supply, return,

exhaust, relief and ventilation air plenums are only permitted in crawl spaces, areas abovefinished ceilings or below finished floors, attic spaces and mechanical equipment rooms.

This is a broader range of areas than the current code permits for plenums. Under the

proposed code, a plenum must be limited to a single fire area. Fuel-fired appliances arenot permitted in plenums, and the maximum air temperature is limited to 250°F, similar

to the current code. As in the current code, the materials of construction must be

appropriate for the environmental conditions, including temperature, humidity and

pressure, to which the plenum will be exposed, except that the proposed code has certainlimitations on gypsum board. Under both codes, firestopping must be maintained. The

current and proposed codes have similar criteria for materials permitted to be exposed


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within plenums with some exceptions. The proposed code allows the use of rigid and

flexible ducts and connectors, combustible materials either enclosed in rated assembliesor labeled for the application, wet plastic fire sprinkler piping, and foam plastic insulation

separated from the plenum by a thermal barrier. Stud wall cavities and the spaces

between floor joists may be used as plenums with certain fire protection limitations. In

flood hazard areas, plenum spaces must either be located above the design flood elevationor be capable of resisting the added loads imposed during a design flood.

RS 13-1

Section MC-603. Duct Construction and Installation. Duct construction and

installation must serve the requirements of the air distribution system, must not interferewith the fire protection system and must meet strength and durability requirements,

similar to current code provisions. For duct sizing, the Reference Standards in the current

Building Code provide equivalent requirements. Materials and conditions of use for air

ducts and air connectors are identical between the two codes, except that the proposed

code adds certain humidity limitations for gypsum board ducts. With regard tounderground ducts, the proposed code provides more regulation, requiring that they be

sloped to a drainage point with access and allowing the use of PVC ducts and plasticfittings. Requirements for air ducts at heat sources are identical to those in the current

code. The proposed code prohibits condensation formation on the exterior of any duct

and has similar requirements as the current Building Code regarding location of ductsrelative to the design flood elevation, the protection of ducts from damage and the

requirements for grilles and registers. The proposed code is identical to the current code

regarding vibration isolation connectors.

RS 13-1, RS 14-1, RS 14-22, 27-316.1, 27-777

Section MC-604. Insulation. As in the current code, the proposed code requires duct

insulation to conform to the Energy Conservation Construction Code of New York State.This section requires that ducts operating at temperatures exceeding 120°F be insulated

such that the exterior surface is limited to 120°F, which is more stringent than the 140°F

in the current Building Code. It is similar to the current code in its requirements for duct

coverings and linings, penetration of rated assemblies, lining installation and thermalcontinuity where fire dampers are required, access to service openings, weatherproof

barriers and the durability of internal duct insulation. In addition, the proposed code

permits the use of foam plastic insulation and accepts appliance listing and labeling wheninsulation is internal to the product. It requires that external duct insulation and factory-

insulated flexible ducts be clearly identified with specific data. It requires a vapor retarder

or equivalent on the outside of insulation covering ducts used for cooling.

RS 13-1, RS 14-1, 27-335.1, 27-792

Section MC-605. Air Filters. Central heating and air conditioning systems must haveapproved air filters installed in the return air system. This section has similar or identical

requirements to those of the current Building Code.


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RS 13-1, RS 14-6, RS 13-15

Section MC-606. Smoke Detection Systems Control. The provisions of this section are

similar to those in the current code. This section states the requirements for smoke

detectors in various air systems. It provides that installation shall be in accordance withthe New York City Electrical Code.

RS 13-1

Section MC-607. Ducts and Air Transfer Openings. This section regulates the

protection of duct penetrations and air transfer openings in fire-resistance-ratedassemblies, largely though not entirely through the use of fire and/or smoke dampers. The

proposed code provides that alternative protection be provided if the dampers interfere

with the operation of a smoke control system. The standards for testing and rating of the

dampers are identical to those of the current code, as are the actuating temperatures for

fire dampers. As in the current code, smoke dampers in the proposed code shall isolateair-handling equipment in systems with a capacity greater than 15,000 cfm. Smoke

dampers are located in conjunction with smoke detectors and the proposed code lists therequirements for their placement. As in the current Building Code, fire dampers are

required at ducts and air transfer openings in firewalls without exception. The proposed

code provides that fire dampers are required in penetrations of fire barriers except if the penetrations are tested, if the ducts are part of a smoke control system, and if the walls

are penetrated by a ducted HVAC system. In contrast, the current Building Code requires

fire dampers and has exceptions stating that dampers are not required if other openingsthrough the wall are not required to be protected, if the ducts are in a store, office, or a

hospital, if a sprinkler system is in use, if the duct is less than 3 square feet in area, or if asleeve is provided. The proposed code states that fire dampers are also required in fire

partitions except where a sprinkler system is in use or the duct materials are of a specified

construction. The proposed code requires smoke dampers at each point where a duct orair transfer opening penetrates a smoke barrier wall or corridor enclosure, except when a

smoke control system is in use or if the ducts are of a specified construction. In contrast,

the current Building Code provides that smoke dampers are required under the same

conditions, except that they are not required when a smoke control system is in use, if theducts provide air to other parts of the building during a fire emergency, and if the

building is an apartment house. At duct penetrations and air transfer openings in shaft

enclosures, the requirements for fire and smoke dampers are similar between the proposed code and the current Building Code, except that under the proposed code fire

and smoke dampers are not required at the penetration of exhaust and supply shafts in

parking garages that are separated from other building shafts by a 2-hour fire-resistancerated construction. With respect to penetrations by air ducts of floor, floor/ceiling

assemblies, or the ceiling membrane of a roof/ceiling assembly, the proposed code is

similar to the current Building Code with minor exceptions. Both codes permit ceiling

radiation dampers to be used where the duct or air transfer penetrates the ceiling of a fire-resistance rated floor/ceiling or roof/ceiling assembly. The proposed code does not permit


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flexible ducts or air connectors to pass through any fire-resistance rated assembly, while

the current code limits them to 2 stories.

27-777.1, RS 13-1, RS 14-1

Section MC-608. Air Outlets and Air Inlets. This section is taken entirely from thecurrent code. The proposed code does not have any additional information on air outlets

and air inlets.

RS 13-1

Section MC-609. Service openings. This section provides the requirements for serviceopenings for horizontal air ducts and plenums. It provides that openings shall be provided

at 20 feet intervals, except that openings are not required if removable inlet/outlet devices

are provided, or if the air has been previously filtered, or if combustible material is not

present in air ducts. The current Building Code has a similar provision.

RS 13-1 Section 2-3.4.3

MECHANICAL CODE – CHAPTER 7 – COMBUSTION AIR

Section MC–701. General. This section gives the requirements for combustion anddilution air for fuel-burning equipment other than gas-fired; the rules for gas-fired

equipment are in the New York City Fuel Gas Code. The general requirements for

provision and circulation of air sufficient for combustion, equipment heat reduction, andflue gas dilution are given. The proposed code generally prohibits combustion air from

being drawn from hazardous locations, refrigeration equipment rooms, or below thedesign flood elevation. The current Building Code gives only a list of industry standards

to be followed for heating and combustion equipment.

RS 14

Section MC–702. Inside Air. As in the current code, the proposed code permits

combustion and dilution air to draw entirely from inside air if the building is not ofunusually tight construction and the space in which the equipment is located is an

unconfined space, a defined term in the proposed code (50 or more cubic feet per 1000

BTU/HR input rating) but not in the current code. The provisions of both codes for aminimum of 1 square inch per 1000 BTU/HR of input rating of the equipment are

identical. If the space is not unconfined, regardless of construction tightness, the

proposed code requires that the room be permanently opened to adjacent space(s) whichwill allow it to meet the criterion for unconfined space, and it also requires two openings,

one high and one low in the room, sized similarly to the requirement in the current

Building Code for a confined space..

RS 14-3


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Section MC–703. Outdoor Air. In conditions where all air is drawn from the outdoors,

the proposed code and current Building Code have identical provisions. Openings shall be provided near the ceiling and floor, and the size of openings is given.

RS 14-3

Section MC–704. Combined Use of Inside and Outdoor Air (Condition 1). This

section governs combustion and dilution air for equipment in confined spaces in

buildings not of unusually tight construction. As provided in MC-702 above, these roomsmust be permanently joined with adjacent spaces to provide the minimum volume of air

relative to the heat input of the equipment, as also provided in the current Building Code.

However, unlike the current code, they must be opened to the outdoors to provide a mixof inside and outdoor air. Openings shall be provided near the ceiling and floor, and the

ratio of openings is stated. This section establishes the method of prorating the

combustion air drawn from the inside air and the outdoor air through each opening.

RS 14-3

Section MC–705. Combined Use of Inside and Outdoor Air (Condition 2). Thissection governs combustion and dilution air for equipment in unconfined spaces in

buildings of unusually tight construction and is identical to the provisions of the current

Building Code. Requirements for location and size of openings are provided.

RS 14-3

Section MC–706. Forced Combustion Air Supply. This section provides that forced air

(such as a fan) provided for combustion equipment shall be supplied at a rate of 1 cfm per2400 BTU/HR. The current Building Code provides that air shall be supplied at a rate of

36 cfm per each gallon of oil fired. The concept of fresh air supply is shown in both

codes with some minor differences

27-807

Section MC–707. Direct Connection. This section governs appliances listed and labeledfor direct combustion air connection to the outdoors, and provides that the equipment

shall be installed in accordance with the manufacturer’s instructions. This section is

comparable with the current Building Code.

RS 14-3

Section MC–708. Combustion Air Ducts. This section is consistent with the current

Building Code giving requirements for combustion air ducts, except that unlike the

current Building Code it prohibits the upper and lower openings required in confined

spaces from being served by the same duct.

RS 14-3


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Section MC–709. Opening Obstructions. Where screens or louvers are installed atopenings required for combustion and dilution air and the percentage of free net area

specified by the manufacturer is not known, both codes assign louver efficiencies. While

the louver efficiencies specified in the proposed code appear to be more stringent than

those of the current Building Code, they agree with the louver efficiencies stated in NYCDEP regulations. Both the current Building Code and the proposed code require that any

volume, smoke, or fire dampers installed at the openings be electrically interlocked so

that the equipment cannot fire when the damper is closed.

27-807, RS 13-1, RS 14-3.

Section MC–710. Opening Location and Protection. This section simply requires

compliance with section MC–401.

MECHANICAL CODE – CHAPTER 8 – CHIMNEYS AND VENTS

Section MC–801. General. This section is similar to the current code, but it provides

additional regulations for sealing of inlet openings in abandoned chimneys. It also prohibits solid-fuel burning appliances from connecting to a chimney venting another

appliance, permits options for lining of low-temperature chimneys, and prohibits

common venting of appliances located on more than one floor. The current BuildingCode is much more detailed regarding chimney construction materials and specifications,

differentiating among low, medium, and high temperature chimneys. The section on

adjoining chimneys is identical to the current Building Code. The proposed code providesadditional requirement for sealing of abandoned chimneys.

27-849, 27-854, 27-855, 27-856, 27-860, 27-867, Table 15-4, RS 15-4, RS 15-16

Section MC–802. Vents. Listed and labeled prefabricated vent systems and field-constructed vent systems are permitted. Those that are prefabricated shall be installed in

accordance with the conditions of their listing and the manufacturer’s instructions. These

rules are similar for both the current Building Code and the proposed code. However,

unlike the current code, vent termination caps are not permitted. It should be noted thatthe current Building Code deals with gas vents, and the vents in the proposed code are for

oil burning equipment.

27-855, RS 14-18*, RS 15-14*, *Both refer to ANSI/NFPA 211-1988

Section MC–803. Connectors. The requirements in the proposed code are similar tothose of the current Building Code, except that the thickness of galvanized steel for

connectors is greater in the proposed code. In addition, the proposed code permits the use

of copper and aluminum, which is not allowed in the current code. Both codes permit the

use of galvanized steel as a connector material.

27-870 through 27-874


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Section MC–804. Direct-Vent, Integral Vent and Mechanical Draft Systems. Thissection governs the removal of flue or vent gases from solid or liquid fueled appliances

and is consistent with the current Building Code. The proposed code prohibits vent

termination caps, which are required for masonry chimneys under the current code. The

proposed code requires a drain of a minimum of 3 inches for condensate, and a similar provision does not exist in the current Building Code. The proposed code permits a

mechanical draft system for manually fired appliances and fireplaces, but only with a

visual and audio alarm system and a smoke detector. There is no comparable provision inthe current Building Code.

27-859, 27-865, RS 14-18

Section MC–805. Factory-Built Chimneys. This section has similar requirements to

those in the current code for factory-built chimneys. The proposed code requires

compliance with the provisions of UL 959 at a lower temperature of flue gas than does

the current Building Code.

27-855, 27-869.01, RS 14-18*, RS 15-14*, RS 15-8[A], RS 15-9, RS 15-10, RS 15-11,RS 15-12, RS 15-15, *Both refer to ANSI/NFPA 211-1988

Section MC–806. Metal Chimneys. This section relies on ANSI/NFPA 211, as does thecurrent Building Code. However, the proposed code requires that the exterior of metal

chimneys be either galvanized or painted, which is not required in the current Building

Code. The current Building Code provides requirements for chimney clearances andmethods of construction for enclosures.

27-861, RS 14-18*, RS 15-14*, Both refer to ANSI/NFPA 211-1988

Section MC–807. Changes in Appliance Fuels. This section was copied from thecurrent Building Code, with slight changes to ensure clarity.

27-869.02

Section MC–808. Reduction of Flue Size. This section was copied from the current

Building Code, and provides that a flue can be reduced in size provided that it meets the

criteria for fuel and chimney type found in the code (808.1). However, the currentBuilding Code provides rules for fireclay flue linings and cast in place chimney linings.

27-869.03

Section MC–809. Chimney Supported from Equipment. This section was copied from

the current Building Code, and provides that chimneys shall not be supported by the

equipment they serve unless specifically designed for such loads.

27-864


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Section MC–810. Test Run and Smoke Test. This section was copied from the currentBuilding Code, with slight changes to ensure clarity. In addition, the last section of the

proposed code provides the methodology for testing, which is not included in the current

Building Code.

27-856, 27-868

Section MC–811. Exhaust Gases from Internal Combustion Engines. This sectionwas copied from the Current Building Code, with slight changes to ensure clarity. The

new code references NFPA 37 for the requirements for discharge openings, and states the

required vertical termination requirements.

27-869

MECHANICAL CODE – CHAPTER 9 – SPECIFIC APPLIANCES, FIREPLACES

AND SOLID FUEL-BURNING EQUIPMENT

Section MC–901. General. This section sets forth the scope of the chapter, whichaddresses the specific appliances and equipment listed, precludes installation of fireplaces

and solid fuel-burning appliances in hazardous locations, and requires that equipment be

installed in accordance with the product listing. The section also sets forth generalrequirements for fireplaces, and refers to the New York City Fuel Gas Code for all gas-

fired appliances and equipment. The code provides that inspection of appliances shall be

in accordance with the requirements of the proposed New York City Building Code. Thissection is similar to the current Building Code.

27-848.01

Section MC–902. Masonry Fireplaces. This section simply references the proposed New York City Building Code. The current Building Code has detailed requirements for

construction, and states the requirements when steel fireplace units are installed, along

with clearance requirements, hearth extensions, fireplace dampers, and accessories. The

provisions are identical.

27-848.07

Section MC–903. Factory-Built Fireplaces. Factory-built fireplaces and hearth

extensions are required to be listed and installed in accordance with the terms of their

listing. Unvented gas-fired appliances are prohibited from factory-built fireplaces, as theyare in the current Building Code. The proposed code references the Energy Conservation

Construction Code of New York State for ventilation requirements, while the current

Building Code states generally that sufficient air shall be provided. The flue requirements

are the same for both codes, providing that separate flues shall be installed for eachfireplace. The current Building Code provides detailed requirements for mounting and


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clearances of chimneys. While there are some differences, both codes have substantially

equivalent provisions.

27-848.08, 27-848.09, RS 14-19, RS 15-15

Section MC–904. Pellet Fuel-Burning Appliances. These appliances shall be listed andinstalled in accordance with their listing, and comply with the Air Pollution Control

Code. No comparable provision exists in the current Building Code. Section MC–905.

Fireplace Stoves and Room Heaters. The proposed code provides that fireplace stovesand room heaters shall be listed and installed in accordance with the terms of their listing.

The proposed code states that ventilation shall be provided in accordance with the

requirements of the Energy Conservation Construction Code of New York State, themanufacturer’s recommendations and Chapter 7 of the proposed code, while the current

Building Code states generally that sufficient air shall be provided. The proposed code

states that the equipment shall comply with the provisions of the New York City Air

Pollution Control Code.

27-848.08, 27-848.09, RS 14-20

Section MC–906. Factory-Built Barbecue Appliances. The proposed code states that

these appliances shall be installed as provided by the code, the manufacturer’s

instructions, and the New York City Fuel Gas Code. It further provides that barbecueappliances meet the requirements for fireplaces as stated elsewhere in the code. The

current Building Code has similar provisions, and states that only natural gas may be

used as a fuel.

27-826.01

Section MC–907. Incinerators and Crematories. The current Building Code does not

regulate crematories. The proposed code provides that incinerators and crematories shall

be installed in accordance with industry standards and the manufacturers’ installationinstructions. It also provides that this equipment shall comply with the Administrative

Code of the City of New York and the New York City Air Pollution Control Code. The

major provisions of the Administrative Code of the City of New York referring toincinerators, 24-117(j) and 24-118, provide that incinerators are not allowed in New York

City except for equipment installed in hospitals, and equipment operated by the New

York City Departments of Sanitation and Transportation.

27-833 - 27-848

Section MC–908. Cooling Towers, Evaporative Condensers, and Fluid Coolers. The

current Building Code requires that cooling towers be constructed of noncombustible

materials, with certain exceptions including locations outside fire districts. The current

Building Code also provides that filling and drift eliminators be constructed ofcombustible materials if a sprinkler system is provided. On the other hand, the proposed

code prohibits the use of combustible materials for indoor equipment, but permits the use


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of combustible construction in the same manner as the current Building Code... The

requirements for vibration isolation are identical in both codes.

27-297(g), 27-338(i), 27-770(b)

Section MC–909. Vented Wall Furnaces. The current Building Code does notspecifically address the requirements for vented wall furnaces; however, the testing of

wall furnaces is covered in the Reference Standards, and refers to UL 730 as does the

proposed code. The proposed code states that furnaces shall not be installed to become afire hazard, and prohibits the installation of ducts into a furnace. The proposed code states

that a furnace door cannot swing within 12 inches of an air inlet or outlet, and it states

that access is to be provided for cleaning. The additional requirements in the proposedcode will result in enhanced safety.

RS 14-6

Section MC–910. Floor Furnaces. The proposed code states that floor furnaces shall beinstalled in accordance with the terms of their listing and the manufacturer’s installation

instructions. Bracing and clearance rules are given. The requirements for floor furnacesin the proposed code are similar to those in the current Building Code.

27-817 - 27-823, RS 14-6

Section MC–911. Duct Furnaces. The current Building Code does not specifically

address the requirements for duct furnaces. The proposed code prohibits the installationof unvented furnaces, and contains requirements for panels, location of draft controls, air,

and duct temperature.

RS 14-6

Section MC–912. Infrared Heaters. The current Building Code does not specifically

address the requirements for infrared heaters. The proposed code requires that infrared

heaters be supported and located so as not to create a fire hazard. The code also provides

that clearances from combustible materials shall be as stated in the manufacturer’sinstructions.

RS 14-6

Section MC–913. Clothes Dryers. The current Building Code refers to various industry

standards for clothes dryers. The proposed code states that the equipment shall beinstalled in accordance with the manufacturer’s instructions, and has UL requirements for

testing. The proposed code provides for a drain connection for condensate.

RS 14-6, RS 14-15


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Section MC–914. Sauna Heaters. The current Building Code refers to various industry

standards for sauna heaters. The proposed code lists safety requirements for theequipment and provides that they shall be installed in accordance with the manufacturer’s

installation instructions. The proposed code also states the requirements for heat and time

controls.

RS 14-6

Section MC–915. Engine and Gas Turbine-Powered Equipment and Appliances. These are not covered in the current Building Code except for exhaust gases from internalcombustion engines; the construction of exhaust pipes and locations of exhaust are given

in the current Building Code. The proposed code references NFPA 37 and Chapter 13 of

the proposed code. These changes from the current code will simplify the requirements.

27-869

Section MC– 916. Pool and Spa Heaters. The current Building Code does not

specifically address the requirements for pool and spa heaters and references nationalstandards. The proposed code states that the equipment shall be installed in accordance

with the manufacturer’s instructions. The proposed code refers to UL standards fortesting.

RS 14-6

Section MC–917. Cooking Appliances. The current Building Code does not specifically

address the requirements for cooking appliances but refers to national standards for theremoval of vapors. The proposed code states that cooking appliances shall be listed,

labeled, and installed in accordance with the manufacturer’s instructions. The proposedcode prohibits the installation of oil-fired cooking appliances, and prohibits the use of

commercial appliances for domestic use. The proposed code states requirements for the

use, installation, clearances, and ventilation for domestic appliances.

27-777(d), RS 13-2, RS 13-3

Section MC–918. Forced-Air Warm-Air Furnaces. The current Building Code refersto various industry standards for warm air furnaces. The proposed code is much more

detailed, providing for UL testing and for installation as provided by the manufacturer

and NFPA 31. The code prohibits the installation of unvented furnaces. It providesspecifications for ducts and heat pumps. It also lists prohibited sources where outside air

may not be drawn.

RS 14-6

Section MC–919. Conversion Burners. The current Building Code does not specifically

cover conversion burners. The proposed code states that conversion burners shall complywith the requirements of ANSI Z21.8. The proposed code requires compliance with

industry standards.


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Section MC–920. Unit Heaters. Unlike the proposed code, the current Building Code provides that unit heaters be accepted for use by the Department of Buildings. The

proposed code provides that unit heaters shall be installed in accordance with the

manufacturer’s instructions, and refers to various industry standards for inspection and

testing. The requirements for support are similar in both codes.

27-813, 27-814, 27-815, 27-816, RS 14-6

Section MC–921. Vented Room Heaters. The current Building Code refers to warm air

heaters and provides that they be installed in accordance with Reference Standards. The

proposed code simply states that the equipment shall be installed in accordance with theconditions of their listing and the manufacturer’s instructions. The provisions are similar.

27-812, RS 14-6

Section MC–922. Kerosene and Oil-Fired Stoves. The proposed code prohibits theinstallation of these appliances. Although this equipment is not covered by the current

Building Code, the installation of kerosene heaters is prohibited in New York City.Therefore, both codes are similar.

Section MC–923. Small Ceramic Kilns. This equipment is not specifically addressed inthe current Building Code. The proposed code covers small kilns that are used for hobby

purposes, and provides that they be installed in accordance with the manufacturer’s

instructions.

Section MC–924. Stationary Fuel Cell Power Plants. This equipment is notspecifically covered in the current Building Code. The proposed code deals with

relatively small plants that have a power output not exceeding 1,000 kW, and provides

for testing in accordance with industry standards. The proposed code states that onlyhydrogen may be used as a fuel, and prohibits on-site storage of flammable gases. This

section basically refers to safety provisions and industry standards.

Section MC–925. Masonry Heaters. This equipment is not specifically covered in thecurrent Building Code. The proposed code simply states that the equipment shall be

installed in accordance with the proposed New York City Building Code.

Section MC–926. Noise Control Requirements. Proposed regulations for noise control

are the same as those required by the current code. Additionally, practitioners must

adhere to the DEP Noise Control Code as is currently required.

27-768, 27-769, 27-770

MECHANICAL CODE - CHAPTER 10 – BOILERS, WATER HEATERS AND

PRESSURE VESSELS


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Section MC-1001. General. This section establishes the minimum safety requirements

for the installation, alteration, and repair of boilers, water heaters and pressure vessels.Portable unfired pressure vessels, interstate commerce commission containers, containers

used for bulk oxygen and medical gas, and certain small unfired pressure vessels (5 cubic

feet or less in volume) are exempted from these requirements. The current code has

similar requirements and similar exceptions for the boilers and pressure vessels describedabove.

27-787, 27-793, RS 14, RS 15

Section MC-1002. Water Heaters. This section describes the applicable codes and

standards for various potable water heaters and hot water storage tanks including electricwater heaters and oil fired water heaters. These heaters shall be installed in accordance

with the manufacturer’s installation and the New York City Plumbing Code and the

proposed code. This section also addresses water heaters utilized both to supply potable

hot water and to provide hot water for space heating applications. Such heaters shall be

manufactured in accordance with ASME Code Section IV requirements and installed inaccordance with the manufacturer’s recommendations and the New York City Plumbing

Code. In addition this section calls for installing a tempering valve for water heaters usedfor space heating applications to limit the maximum potable hot water temperature to

140°F for scald protection.

There is no direct mention of potable water heaters in the current Building Code;

however, the reference standards listed below include all the water heaters addressed in

the above paragraph. The design and installation requirements are similar in both the proposed and current New York City codes.

RS 12, RS 14 and RS 16

Section MC-1003. Pressure Vessels. This section states that all pressure vessels shall bear the label of an approved agency and shall be installed according to the

manufacturer’s instructions. All piping, fittings, joints and connections associated with

pressure vessels shall be designed for specific applications, and all welding on pressure

vessels and associated piping shall be performed by certified welders in compliance withnationally recognized standards, such as ASME Section VIII and IX and 12 NYCRR Part

14.

The current Building Code has the same requirements.

27-825, RS 13-5, RS 14-4

Section MC-1004. Boilers. This section addresses the listing and labeling requirements

for oil-fired and electric boilers, and lists the applicable UL standards. It also lists the

applicable ASME Boiler and Pressure Vessel code sections, New York State Departmentof Labor Code Rules and NFPA codes. It specifies working clearances required to allow

access for inspection, maintenance, and repair around and on top of the boilers for


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various types of boilers. It calls for mounting of boilers on a level base for equal

distribution of weight of the equipment, and mandates that equipment requiring vibrationisolation be designed by a registered design professional. Boiler room enclosures shall

comply with the proposed New York City Building Code and the proposed code. This

section also describes burner control systems for gas and oil modulating burners for

various burner oil consumption rates and boiler sizes.

The current code has similar requirements in its reference standards.

27-180, 27-182, 27-418 through 27-424, 27-824, 27-825, RS 14-5A, RS 14-5B, RS 14-6,

RS 14-9

Section MC-1005. Boiler Connections. This section calls for providing a shut-off valve

in all supply, discharge and return piping, depending on the type of boiler. For multiple

boiler installations, it calls for each boiler or modular boiler to have individual shut-off

valves in all supply, discharge and return lines to and from boilers. However, shut-off

valves are not required in a system having a single low pressure steam boiler of 350,000Btu/h heat input or less. This section requires that the water supply to all boilers be

connected in accordance with the New York City Plumbing Code.

The current code has similar requirements.

RS 14-5A, RS 14-5B, RS 14-6

Section MC-1006. Safety Pressure Relief Valves and Controls. This section lists therequirements for safety valves, safety relief valves, pressure relief valves and pressure-

limiting devices for steam boilers, hot water boilers, and pressure vessels respectively to protect them from over-pressure. It calls for utilizing listed and labeled valves only, and

specifies the minimum electric power supply and control system requirements for boiler

system applications. It calls for locating the remote control shut-down switches outsideall means of egress from the boiler room if practical, to cut-off the oil and/or gas fuel

supply and combustion air in case of an emergency.

The current code has similar requirements..

27-825, 27-830(b), RS 16 P107.26(b)

Section MC-1007. Boiler Low-Water Cutoff. This section mandates that all steam and

hot water boilers be protected with dual low-water cutoff controls, and that the low water

cutoff devices be mounted on separate (isolated) steam side and water side connectionsindependent of other control devices or valves, such as other switches, gauges, etc. It

requires the low-water cutoff control to automatically stop the combustion operation by

cutting off the fuel supply when the water level drops below the lowest safe water level

as required by the ASME codes and boiler manufacturers’ instructions.



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RS 14-5A, RULE HG-614

Section MC-1008. Boiler Blowoff/Blowdown Valves. This section mandates that

boilers be equipped with blowoff/blowdown valve(s), as recommended by the boiler

manufacturers, and in accordance with the applicable ASME code. It requires that the blowdown valves discharge to a safe location in accordance with the New York City

Plumbing Code.


RS 14-5A, 5B, RS 14-6

Section MC-1009. Hot Water Boiler Expansion Tank. This section specifies the

minimum requirements for installing hot water boiler expansion tanks in hot water

system applications. It includes both closed-type and open-type expansion tank sizing

requirements, and specifies minimum height and overflow pipe diameter requirements foropen-type expansion tanks. It calls for tank overflow discharge to be routed to the

drainage system in accordance with the New York City Plumbing Code.

There is no direct mention of hot water expansion tanks in the current code; however, its

reference standards cover hot water system design.

RS 14-5A, RS 14-5 B

Section MC-1010. Gauges. This section specifies pressure gauge, temperature gauge,

and water gauge glass requirements for hot water and steam boilers. It also describesspecific requirements for installing water gauge glass and pressure gauges for steam

boilers.

The reference standards for the current code have similar requirements.

RS 14-5A, RS 14-5B, RS 14-6

Section MC-1011. Tests. This section describes the requirements for initial acceptance

test of boilers and pressure vessels upon completion of assembly and installation, as well

as periodic boiler inspection requirements. The periodic boiler inspection requirementsare specified in detail in Section 28-303 of the Administrative Code of the City of New

York. It calls for a qualified boiler inspector to perform all final inspections and tests

upon completion of construction, and to perform annual boiler inspections on boilers inaccordance with Section 204 of the Labor Law of the State of New York.

The current code has identical inspection and testing requirements for both, the initial

acceptance test and the periodic boiler inspections.

27-793, 27-794


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MECHANICAL CODE – CHAPTER 11 – REFRIGERATION

Section MC-1101. General. This section addresses the scope of this chapter, which

governs the design, installation, construction, and repair of refrigeration systems

including permanently installed refrigeration storage systems. It mandates thatrefrigeration systems comply with the requirements of this code, and ASHRAE 15,

entitled Safety Standard for Refrigeration Systems, except as modified by this code. This

section addresses the issues of changing refrigerant in existing systems, and gas and oilfired absorption systems. It calls for testing factory built refrigeration equipment in

accordance with applicable UL standards. It also specifies appropriate sections of the

code for signs, name plates, and operation and emergency shutdown instructions forrefrigeration systems.

The current Building Code with a revised Reference Standard 13-6 has identical scope.

27-771, 27-777(f), RS 13-6 revised April 27, 2005, ANSI/ASHRAE 15-2001

Section MC-1102. System Requirements. This section addresses the refrigerationsystem classification, allowable refrigerants, maximum quantity permitted, enclosure

requirements, location limitations, and field pressure test requirements criteria based on

type of refrigerant to be used and building occupancy type. It also addresses the issues ofmixing refrigerants including refrigerant blends, and purity requirements of new,

recovered and reclaimed refrigerants. It references various sections of the proposed code

for compliance.

The current Building Code with the revised Reference Standard 13-6 dated April 27,2005 addresses all of the above topics and issues.

RS 13-6 revised April 27, 2005, ANSI/ASHRAE 15-2001

Section MC-1103. Refrigeration System Classification. This section addresses the

various building occupancy classifications and system classifications of refrigeration

systems. Locations of refrigerating systems are determined by building occupancyclassifications that consider the ability of people to respond to potential exposure to

refrigerants in case of a refrigerant leak. It addresses building occupancy classifications

of institutional occupancy, public assembly, residential and commercial occupancies, andmercantile, industrial and mixed occupancies.

The refrigeration system classifications are based on the degree of probability ofrefrigerant leakage from a failed connection, seal, or component that could enter an

occupied area. This distinction is based on basic design or location of the components.

The systems are classified as low probability systems or high probability systems based

on their system design such as double indirect open spray system, indirect closed system,direct system and indirect open spray system, etc.


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The current Building Code addresses the same refrigeration system classifications.

RS 13-6 revised April 27, 2005, ANSI/ASHRAE 15- 2001

Section MC-1104. System Application Requirements. This section addresses

refrigeration system application requirements and imposes certain restrictions on the useof high flammability and high toxicity refrigerants for certain applications. It states that

use of Group A3 or Group B3 refrigerant is generally prohibited, except for certain

industrial occupancies where it may be permitted on a case by case basis by specialapproval from the commissioner of the Department of Buildings and the commissioner of

the Fire Department. It states that a total of all Group A2, B2, A3, and B3 refrigerants

shall not exceed 550 pounds in occupied areas or machinery rooms of institutionaloccupancies. It prohibits the use of Group B1, B2, B3, A2, and A3 refrigerants for human

comfort application in high-probability systems. It calls for the use of a machinery room

where the quantity of refrigerant in an independent circuit of a system exceeds the

quantity listed in refrigerant classification Table 1103.1. It provides details on when

machinery rooms are not required for industrial occupancies and requirements forrefrigerated rooms for manufacturing, food, beverage, meat cutting and other processes

and storage.

The current code addresses similar requirements, but does not have as much detail. The

overall scope of both codes is the same, and restrictions on use of certain refrigerants aresimilar.


Section MC-1105. Machinery Room General Requirements. This section addressesrefrigeration machinery room requirements including room design and construction,

refrigerant detector requirements, ventilation, make-up air, and room exhaust air

discharge location. It calls for dedicated supply and exhaust ducts to and from themachinery room which will serve only the machinery room and no other occupied area,

except in hardship cases. Common supply and exhaust ducts shared with human occupied

areas may be permitted in hardship cases for existing buildings retrofit utilizing

refrigerant Group A1 or R123 with special permission from the commissioner. Special permission is also required for discharge of Group A2, B2, A3, and B3 refrigerants from

the both the Buildings Commissioner and the Fire Commissioner. In addition, clearly

identified switches of the break-glass type are mandated to provide off-only control forthe compressors, and on-only control for machinery room ventilation fans. Such switches

shall be located outside each entrance to machinery rooms, or located immediately inside

the machinery room if the outside location is impracticable.

The current Building Code has similar requirements.



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Section MC-1106. Machinery Room, Special Requirements. This section specifies

additional special requirements and restrictions for machinery rooms in addition to thegeneral requirements addressed in Section 1105. These special requirements are

mandated generally for Group A2, B2, A3 and B3 (higher flammability and higher

toxicity) refrigerants systems. It calls for machinery room design to conform to Class 1,

Division 2, and hazardous location classification requirements of the New York CityElectrical Code. It also calls for a clearly identified break-glass type switch to provide

off-only control for all electrically energized equipment and appliances in the machinery

room. It calls for self-closing, tight fitting fire doors, and at least one hour fire resistiveconstruction with tight walls, floors and ceiling for machinery rooms.



Section MC-1107. Refrigerant Piping. This section addresses refrigerant piping

requirements including piping installation and testing. It specifies the acceptable pipematerials for piping and tubing including pipe wall thickness requirements for various

pipe sizes and refrigerant Groups A1, B1, A2, B2, A3 and B3. It specifies acceptableASTM specifications for various materials for piping and tubing, and mandates that all

joints and refrigerant containing parts located in air ducts of air-conditioning systems

carrying conditioned air to and from human occupied space be constructed in a mannerwhich results in approved, gas tight, leak proof connections.



Section MC-1108. Field Test. This section mandates that all refrigerant-containing parts

of refrigeration system erected on premises (field erected) be field tested except for listedand labeled factory tested equipment (such as compressors, condensers, pressure vessels,

evaporators, safety devices and gauges). The field assembled components should be field

tested and proved tight after the system installation, and before the system operation.

Certain small systems using Group A1 refrigerant have less stringent testingrequirements. This section also addresses test gases, test apparatus, and field test

documentation requirements.



Section MC-1109. Periodic Testing. This section mandates that periodic testing of

emergency devices and systems be conducted and the result logged in accordance with

the manufacturer’s instructions and as required by the Fire Commissioner. The periodictesting shall include treatment and flaring systems, valves and appurtenances necessary

for the operation of emergency refrigeration control boxes, fans and associated equipment


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required to operate emergency purge ventilation systems, and refrigerant leak detection

and alarm systems.

The current code is not very specific regarding such periodic testing requirements and it

leaves periodic testing of critical components and equipment to the discretion of the

refrigeration system owner/operator. However, such periodic testing is alwaysrecommended by the equipment manufacturer and the Fire Department.

MECHANICAL CODE – CHAPTER 12 – HYDRONIC PIPING

Section MC–1201. Scope. This section sets forth the scope of the chapter, which applies

to piping systems that are a part of heating and cooling systems. For systems providingdrinking water, the provisions of the New York City Plumbing Code shall apply. The

code states that hydronic piping systems shall be sized for the load. This section is

compatible with the current Building Code.

27-830, 27-896, RS 16

Section MC–1202. Material. The proposed code allows for the re-use of pipingmaterials, and provides that the material shall be rated for the temperature and pressure of

the intended use. All materials shall be approved for use with the intended system. For

specific materials, the proposed code provides standards for the use of hydronic pipingincluding plastic materials. The current Building Code does not provide any standards for

the materials to be used for hydronic piping.

RS 16

Section MC–1203. Joints and Connections. This section of the proposed code states the

requirements for joining piping materials. For dissimilar piping materials, the code

provides that adapter fittings shall be used, while the current Building Code is much moredetailed, giving requirements for each connection, such as a ring for a cast iron to clay

connection. The proposed code states that pipe terminals shall be prepared for

construction; a similar provision is lacking in the current Building Code. The proposed

code allows the use of plastic fittings, in contrast to the current Building Code which hasno similar provision.

RS 16

Section MC–1204. Pipe Insulation. The proposed code states that pipe insulation shall

comply with the requirements of the Energy Conservation Construction Code of NewYork State, with a maximum flame spread index of 25 and a smoke-developed index not

exceeding 450. The current Building Code requires that insulation shall have a maximum

flame spread rating of 25, with a maximum smoke developed rating of 50. The current

Building Code has detailed requirements for insulation of piping at temperaturesexceeding 165ºF.


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27-809, 27-811, RS 16

Section MC–1205. Valves. This section provides that shutoff valves shall be provided on

both supply and return lines of heat exchangers, except if they are integral with a boiler

unit. In contrast, the current Building Code provides for a relief or pressure relief valve

on the heater side of the shutoff valve. The proposed code requires shutoff valves on building supply lines, pressure vessels, and connections to mechanical equipment. Relief

valves are required on reduced pressure line piping. The current Building Code also

requires that relief valves discharge at not more than 1½ times the system pressure, andthis provision is lacking in the proposed code.

27-830, RS 16

Section MC–1206. Piping Installation. This section provides that piping systems shall

be designed so that they may be drained. Potable water systems shall be protected from

backflow, and this is also provided for in the current Building Code. The proposed code

also states that penetrations shall be protected, as does the current Building

Mechanical Code Sbs

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