Post on 04-May-2018
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Course Outline
Energy-Saving Strategies for Rooftop VAV Systems
Rooftop variable-air-volume (VAV) systems are used to provide comfort in a wide range of building types and climates. This ENL discusses HVAC system design and operating strategies that can save energy in these systems.
By attending this broadcast, you will be able to: 1. Explain the basic concepts of a rooftop VAV system, including the basic components, its advantages and
disadvantages, and minimum code requirements. 2. Summarize cost-effective strategies to reduce the energy used by rooftop VAV systems. 3. Explain how to analyze the economic benefit of various energy-savings strategies. 4. Summarize system-level control strategies that improve the performance and flexibility of rooftop VAV
systems. Program Outline: 1) Welcome, agenda, introductions 2) Overview of a rooftop VAV system
Basic components Benefits and challenges Minimum code requirements
3) Equipment configuration strategies a) High-efficiency versus standard efficiency equipment (EER, IPLV) b) Air-to-air energy recovery c) Relief fan versus return fan d) Air-cooled or evaporative condensing e) Hot gas bypass f) Fan-Powered VAV g) ECMs on fan-powered VAV boxes
4) System design strategies a) Single-zone VAV (arenas, auditoriums, gymnasiums, sanctuaries) b) Hot gas reheat for unoccupied humidity control c) DOA unit delivering cold OA direct to spaces or dual-duct boxes
5) Optimized system control strategies a) Airside economizing b) Optimum start/stop c) Fan-pressure optimization d) Supply-air temperature reset e) Ventilation optimization: DCV (TOD schedule, occupancy sensor,
CO2 sensor) combined with ventilation reset 6) Example TRACE analysis 7) Operation & Maintenance
a) Proper maintenance b) Balancing and commissioning (ongoing auto-commissioning)
8) Summary
Energy Saving Strategies for Rooftop VAV Systems
Phil Baggett | marketing engineer – large rooftops | Trane
Since starting with Trane in 1968 Phil has served in several roles of increasing responsibility in manufacturing engineering, product marketing, training, product planning, and product management organizations. Phil's primary responsibility as marketing engineer for large rooftop products is to identify and implement product change opportunities, and new product-platform development initiatives. He is also responsible for identifying and assisting in the development of sales and application tools to support those initiatives.
John Murphy | senior applications engineer | Trane
John has been with Trane since 1993. His primary responsibility as an applications engineer is to aid system design engineers and Trane sales personnel in the proper design and application of HVAC systems. His main areas of expertise include dehumidification, air-to-air energy recovery, psychrometry, ventilation, and ASHRAE Standards 15, 62.1, and 90.1. John is the author of numerous Trane application manuals and Engineers Newsletters, and is a frequent presenter on Trane’s Engineers Newsletter Live series of satellite broadcasts. He is also the primary author of the Trane Air Conditioning Clinics, a series of training manuals on HVAC fundamentals. John is a member of ASHRAE, has authored several articles for the ASHRAE Journal, and is a member of that society’s “Moisture Management in Buildings” and “Mechanical Dehumidifiers” technical committees.
Paul Solberg | senior principal applications engineer | Trane
A mechanical engineer from the University of Wisconsin at Platteville, Paul is a 26-year veteran of Trane. He specializes in compressor and refrigeration systems, and has authored numerous Trane publications on these subjects, including application manuals, engineering bulletins, and Engineers Newsletters. Paul served in the technical service and applications engineering areas at various manufacturing locations, where he developed particular expertise supporting split systems, small packaged chillers, rooftop air conditioners, and other unitary products.
Justin Wieman| C.D.S. marketing engineer | Trane
After finishing the Trane Graduate Training Program in 2001, Justin joined the Customer Direct Service (C.D.S.) group as a marketing engineer. Since then he has provided support for various Trane software applications. Presently he is team leader for Trane’s Analysis Software group, and project manager for the Trane Air-Conditioning Economics (TRACE™ 700) product family.
engineers newsletter live Presenter Biographies
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
1
Energy-Saving Strategies forRooftop VAV SystemsRooftop VAV Systems
ananEngineers Newsletter Live telecast© 2006 American Standard All rights reserved
Equipment configurations
rooftop VAV systems
Energy-Saving Strategiesrooftop VAV systems
Energy-Saving Strategies Equipment configurations
Alternative system designs
Optimized system controls
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
2
Ingersoll Rand
Energy-Saving Strategies for Rooftop VAV Systems - Course ID 0090004836
1.5
“Trane” is a Registered Provider with The American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records of this program will be reported to CES Records for AIA members. Certificates of Completion for non-AIA members available on request.
This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product.Questions related to specific materials,methods, and services will be addressedat the conclusion of this presentation.
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
3
Copyrighted MaterialsCopyrighted MaterialsThis presentation is protected by U.S. and international copyright laws. Reproduction, distribution, display, and use of the presentation without written permission of Trane is prohibited.
© 2010 Trane, a business of Ingersoll-Rand. All rights reserved.
AIA continuing education
Learning ObjectivesAIA continuing education
Learning ObjectivesParticipants will learn the following aboutParticipants will learn the following aboutrooftop VAV systems:
Cost-effective strategies to reduce energy use
How to analyze economic impact of various energy-saving strategies
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
4
Today’s PresentersToday’s Presenters
Justin Wiemanmarketingengineer
Phil Baggettmarketingengineer
Today’s PresentersToday’s Presenters
Paul Solbergapplicationsengineer
John Murphyapplicationsengineer
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
5
ASHRAE Standard 90.1 and 62.1 Requirementsand 62.1 Requirements
E i Energy-saving strategies for rooftop VAV systems
Rooftop VAV SystemRooftop VAV Systempackaged DXpackaged DXrooftop air conditionerrooftop air conditionerrooftop air conditionerrooftop air conditioner
supplysupplyductworkductwork
returnreturnductworkductwork
supplysupply--airairdiffusersdiffusers
BASBAS
VAVVAVterminalterminal
unitsunits
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Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
6
SatisfySatisfy Occupant comfort Occupant comfort
Code (or standard) minimum requirements
ASHRAE 90.1-2004
ASHRAE 62.1-2004
ASHRAE 90.1-2004
Rooftop VAV SystemsASHRAE 90.1-2004
Rooftop VAV Systems Mandatory Prescriptive Mandatory
Equipment efficiency
Controls
Prescriptive
Economizers
Limitation on reheat
Design fan power
Fan control Fan control
Energy recovery
Hot gas bypass
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
7
packaged rooftop (air-cooled)
Equipment Efficienciespackaged rooftop (air-cooled)
Equipment EfficienciesSize Category Heating
S ti TMinimum Effi iSize Category Section Type Efficiency
<65,000 Btu/h All 12.0 SEER*
≥65,000 Btu/h and
<135,000 Btu/h
Electric ResistanceOther
10.3 EER10.1 EER
≥135,000 Btu/h and
<240,000 Btu/h
Electric ResistanceOther
9.7 EER9.5 EER
≥240,000 Btu/h and
Electric ResistanceOthe
9.5 EER, 9.7 IPLV9 3 EER 9 5 IPLV and
<760,000 Btu/hOther 9.3 EER, 9.5 IPLV
≥760,000 Btu/h Electric ResistanceOther
9.2 EER, 9.4 IPLV9.0 EER, 9.2 IPLV
*NAECA requires 13.0 SEER
Zone Thermostatic ControlsZone Thermostatic Controls
Required for each zone Required for each zone
Perimeter can be treated differently
≥5º F deadband
Dual setpoint or deadband(can be soft a e fo DDC)(can be software for DDC)
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
8
systems ≥ 15,000 Btu/h
Automatic Shutdownsystems ≥ 15,000 Btu/h
Automatic Shutdown Automatic 7-day/week time clock Automatic 7-day/week time clock
with 10-hour battery backup
Exception: 2-day/week thermostat for residential applications
Occupancy sensor
Manually operated timer(maximum duration: 2 hours)
Security system interlock
systems ≥ 15,000 Btu/h
Setback Controlssystems ≥ 15,000 Btu/h
Setback Controls Climate zones 2-8: Climate zones 2-8:
Lower heating setpoint to 55°F or less
Climate zones 1b, 2b, 3b (hot/dry):Automatically restart, temporarily operate
Raise cooling setpoint to 90°F or higher, or
Prevent high space humidity levels
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
9
mandatory HVAC provisions
Other Off-Hour Controlsmandatory HVAC provisions
Other Off-Hour Controls Provide optimum start if system Provide optimum start if system
supply-air capacity > 10,000 cfm
Zone isolation:
25,000 ft² maximum zone size on one floor
Isolation devices to shut off outdoor and exhaust airflow
Central systems capable of stable operation
ventilation
High Occupancyventilation
High OccupancyIf outdoor airflow > 3 000 cfm and If outdoor airflow > 3,000 cfm and design occupancy > 100 p/1000 ft²…
Automatically reduce outdoor air intake below design requirements when spaces are partially occupied
E tiException:Systems with exhaust-air energy recovery complying with Section 6.5.6.1
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
10
ASHRAE 90.1-2004
Rooftop VAV systemsASHRAE 90.1-2004
Rooftop VAV systems Mandatory Prescriptive Mandatory
Equipment efficiency
Controls
Prescriptive
Economizers
Limitation on reheat
Design fan power
Fan control Fan control
Energy recovery
Hot gas bypass
System 135,000 Btu/h?Economizer required
Std 90.1 economizer requirements
Exception (a)
4bEconomizerNOT required
© 2
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bdry
amoist
System 65,000 Btu/h?Economizer required
q
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
11
airside economizer use
Exceptionsairside economizer use
Exceptions(a)(a) Individual fan-cooling units with(a)(a) Individual fan cooling units with
less-than-minimum capacities installed in specific climate zones
(b)(b) Systems with gas-phase outdoor air cleaningto meet ASHRAE Standard 62
(c)(c) Systems with > 25% of supply airserving spaces humidified aboveserving spaces humidified above35°F DP for process needs
(d)(d) Systems with condenser heat recovery
airside economizer use
Exceptionsairside economizer use
Exceptions(e)(e) Residential space systems with capacities(e)(e) Residential space systems with capacities
< 5× limit in Exception (a)
(f)(f) Space sensible cooling load transmission+ infiltration load at 60°F
(g)(g) Systems that operate < 20 hr/wk
(h)(h) Supermarket applications, where outdoor air (h)(h) Supermarket applications, where outdoor air for cooling affects open refrigerated cases
(i)(i) Systems with high mechanical cooling efficiency ( Table 6.3.2 requirements)
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
12
Simultaneous Heating–CoolingSimultaneous Heating–Cooling
Zone controlsZone controls No reheating No recooling No mixing or
simultaneously supplying mechanically-cooled and ymechanically-heated air
Exceptions based on zone airflow
simultaneous heating–cooling
Exceptionssimultaneous heating–cooling
ExceptionsZone airflow does not exceed Zone airflow does not exceed whichever is largest:
ASHRAE Standard 62 zonerequirements for outdoor air
0.4 cfm/ft²
30% of supply air 30% of supply air
300 cfm
ASHRAE Standard 62 equation
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
13
simultaneous heating–cooling
Exceptionssimultaneous heating–cooling
Exceptions Zones with special Zones with special
pressurization requirements
Zones with code-required minimum circulation rates
Sit d it Site-recovered or site-solar energy provides ≥ 75% of reheat energy
dehumidification
Exceptions dehumidification
Exceptions Reducing supply airflow to 50% Reducing supply airflow to 50%,
or minimum ventilation rate
Systems < 6.67 tons that can unload at least 50%
Systems smaller than 3.3 tons
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
14
dehumidification
Exceptionsdehumidification
Exceptions Systems with specific humidity Systems with specific humidity
requirements (museums, surgical suites)
75% of reheat/recool energy is site-recovered or site-solar
Fan Power LimitationFan Power Limitation
Supply air volume Constant volume Variable volume
< 20,000 cfm 1.2 hp/1,000 cfm 1.7 hp/1,000 cfm
≥ 20,000 cfm 1.1 hp/1,000 cfm 1.5 hp/1,000 cfm
Allowable nameplate motor power
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
15
Air System ControlAir System ControlVAV fan controla co o
Motors ≥ 15 hp require
Variable-speed drive or
Vaneaxial fan with variable-pitch blades or
Design wattage ≤ 30% at 50% air volume
DDC systems must include setpoint reset (fan-pressure optimization)
Airside Energy RecoveryAirside Energy Recovery Required if: Required if:
Supply air capacity ≥ 5,000 cfm
Minimum outdoor air ≥ 70%
Recovery system effectiveness ≥ 50%
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
16
Maximum HGBP capacity,% f l i
Rated capacityf
Hot Gas BypassHot Gas Bypass
% of total capacityof system
≤ 240,000 Btu/h 50%
> 240,000 Btu/h 25%
Applied in systems with stepped or ti l dicontinuous unloading
Exception: Packaged unitary systems≤ 90,000 Btu/h (7.5 tons)
ASHRAE 62.1
Ventilation RequirementsASHRAE 62.1
Ventilation Requirements Design Operation: Design
Calculate zone ventilation airflow
Determine air distribution effectiveness
Operation:
Dynamically calculate system ventilation airflow
In VAV system, fixed damper position does not
Calculate system design ventilation intake airflow
position does not meet requirements
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
17
Base Rooftop VAV SystemBase Rooftop VAV System Equipment Airside energy Equipment
efficiency
Zone controls
Economizer
Simultaneous heating and cooling
Airside energy recovery
Hot gas bypass
Ventilation
heating and cooling
Design fan power
Fan control
Equipment ConfigurationStrategiesStrategies
Energy-saving strategies for rooftop VAV systems
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
18
High-Efficiency EquipmentHigh-Efficiency Equipment
Reduced operating Higher first costBenefits Drawbacks
Reduced operating cost
Potential energy rebates
Meet mandated energy codes
Higher first cost
Extended return on investment in some areas
Environmentally intelligent, reduces greenhouse gas emissions
High-Efficiency EquipmentHigh-Efficiency Equipment High-efficiency supply and exhaust High-efficiency supply and exhaust
fan motors
Insist on NEMA Premium rated
Additional evaporator coil rows
Additional condenser coil capacity Additional condenser coil capacity
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
19
High-Efficiency EquipmentHigh-Efficiency Equipment Standard efficiency rooftop (Alt 1) Standard efficiency rooftop (Alt 1)
9.6 EER
604 gross MBH
High-efficiency rooftop (Alt 2)
10 4 EER 10.4 EER
644 gross MBH
High-Efficiency EquipmentHigh-Efficiency Equipment Example energy savings Example energy savings
Three story 60,000 sq. ft office building
VAV with reheat system
Default settings forbuilding type and exposuresbuilding type and exposures
Alameda, CA weather data and PG&E utility rate
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
20
System Analyzer™System Analyzer™Alt 1
$ 8 286Alt 2
$18,286$17,300
High-Efficiency EquipmentHigh-Efficiency Equipment Reduced fossil fuel emissions Reduced fossil fuel emissions
CO2 -5,415 lbm/yr SO2 -5,956 gm/yr NOx -8,122 gm/yr
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
21
Air-to-Air Energy RecoveryAir-to-Air Energy Recovery
total-energywheel
EAEA
OAOA
180
160 h
85
80
wet-bulb temperature, °F
total-energy recovery:
Example in Cooling Mode
140
120
100
80
60
40
um
idity ratio
, grain
s/lb o
f dry
75
70
65
60
5550
45
OA
RA
OA'
2.2 tons1,000 cfm
40
20
0
air
11030 40 50 60 70 80 10090dry-bulb temperature, °F
4035
30
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pre-cools andpre-dehumidifies OA
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
22
180
160 h
85
80
wet-bulb temperature, °F
total-energy recovery:
Example in Heating Mode
140
120
100
80
60
40
um
idity ratio
, grain
s/lb o
f dry
75
70
65
60
5550
45 RA
24 MBh1,000 cfm
40
20
0
air
11030 40 50 60 70 80 10090dry-bulb temperature, °F
4035
30
OA
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OA'pre-heats andpre-humidifies OA
DrawbacksBenefits
Air-to-Air Energy RecoveryAir-to-Air Energy Recovery
Reduces cooling, dehumidification, heating, and humidification energy
Allows equipment downsizing
Increases fan energy
Requires exhaust air be routed back to rooftop unit
downsizing
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Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
23
Size energy-recovery device for
Air-to-Air Energy RecoveryAir-to-Air Energy Recovery Size energy-recovery device for
minimum outdoor airflow
Strive for balanced airflows
Integrate control with airside economizer operation
How much cross-leakage is acceptable?
Provide a means of capacity control
Building Pressure ControlBuilding Pressure Controlintake airflow
relief airflow
+
+
+
+
+
++
+
+
+
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
24
control based on RA plenum pressure
Central Return Fancontrol based on RA plenum pressure
Central Return FanRARA
PPreturn fanRLRL RARA
spacespace
PP
PP
return fan
reliefdamper
RLRL
SASA
EAEAspacespaceflow-measuring
damperOAOA
modulated control
Central Relief Fanmodulated control
Central Relief FanRARARLRL
PPRARARLRL
spacespace
relief fanPP
SASA
OAOA
EAEA
spacespaceflow-measuringdamper
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Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
25
Return vs. Relief Fan?Return vs. Relief Fan?
P ti l t ti l d S l f t b Relief FanReturn Fan
Partial static placed on return fanUse in systems with high RA pressure drop
Supply fan must be sized for entire static
Two continuous motors to provide ventilation air
Intermittent relief fan operationReduced operating cost
(+) Pressurized diverting plenumRA leakage out relief dampers
(-) Pressurized diverting plenumOA leakage in relief dampers
Air-Cooled CondenserAir-Cooled Condenser
llpropellerfanfan
OAOA
finned-tubecondenser coils
OAOA
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Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
26
Evaporative CondenserEvaporative Condenserfanfan
condenser condenser coilcoil
sumpsump pumppump
condensing
Air-Cooled vs. Evaporativecondensing
Air-Cooled vs. Evaporative
pre
ssu
re
expansion
air-cooledcondenser
evaporativecondenser
enthalpy
evaporator compressor
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
27
Avoid Hot Gas BypassAvoid Hot Gas Bypass Purpose Purpose
Frost prevention
Stabilize discharge temperature
HGBP
One step greater capacity One step greater capacity
poor energy efficiency
Avoid Hot Gas BypassAvoid Hot Gas Bypass Choose units that maximize the Choose units that maximize the
stages of compression
Use intertwined coils
Don’t oversize rooftop tonnage… maximizes suction temperature
Use frost control
Remember that the average air condition is what is important
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
28
parallel
Fan-Powered VAVparallel
Fan-Powered VAV
cool primary airfrom rooftop unit
i i l d
heating coil(second stage of heat)
warm air recirculatedfrom ceiling plenum(first stage of heat)
ECM Fan-Powered BoxesECM Fan-Powered BoxesDrawbacksBenefits
Reduces VAV terminal fan energy
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
29
ECM EfficiencyECM Efficiency0.6
gy i
np
ut,
kW
/cf
m
0.5
0.4
0.3
0.2
permanent splitcapacitor (PSC) motor
500 1000 15000 25002000
airflow, cfm
en
erg 0.1
0
electrically-commutatedmotor (ECM)
ECM Fan-Powered BoxesECM Fan-Powered BoxesDrawbacksBenefits
Reduces VAV terminal fan energy
Higher first cost
Greater airflow range
Capability for self-balancing
Potential for disruptive harmonic currents
g
Less-annoying sound levels
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
30
Equipment Configuration StrategiesEquipment Configuration Strategies High efficiency Avoid hot gas High efficiency
Energy recovery
Exhaust fan
Evaporative condenser
Avoid hot gas bypass
Fan-powered boxes
Electronically commutated motors
Alternative System DesignsSystem Designs
E i Energy-saving strategies for rooftop VAV systems
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© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
31
Single-Zone VAVSingle-Zone VAV
spacespaceTT
RARAEAEA
TT
SASAOAOA
single-zone VAV
Benefitssingle-zone VAV
Benefits Lower operating cost Lower operating cost…
Reduces fan speed at part load
Reduced sound levels… Reduces fan-generated noise at part load
Improved dehumidification…Continues to supply cool, dry air at part load
Simple controls and standard equipment
a Trane Engineers Newsletter Live online program
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© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
32
single-zone VAVApplication Considerationssingle-zone VAVApplication Considerations Large zones should have Large zones should have
uniform loads
Design air distribution system for variable airflow
Short, symmetrical ducts
Size for low-to-medium duct velocities
Diffusers that prevent “dumping”
Consider need for zone heating
Prevent overcooling the zone
single-zone VAVApplication Considerationssingle-zone VAVApplication Considerations Prevent overcooling the zone…
SA temperature reset
Employ CO2-based DCV
a Trane Engineers Newsletter Live online program
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© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
33
single-zone VAV
CO2-Based DCVsingle-zone VAV
CO2-Based DCV
spacespace
CO2CO2TT
RARAEAEA
flow-measuringdamper
TT
SASAOAOA
humidity control
Unoccupied Modehumidity control
Unoccupied Mode
spacespace
RHRHreheat
RA
SASA
spacespacedehumidification
a Trane Engineers Newsletter Live online program
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© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
34
unoccupied humidity control
Hot Gas Reheatunoccupied humidity control
Hot Gas Reheatevaporatorairflow
reheatcoil
condenser
airflow
reheatvalve
compressor
Dedicated OA SystemDedicated OA Systemdedicatedoutdoor-air unit
VAV rooftop(recirculating)
SA RA CA
OA
outdoor-air unit(recirculating)
dual-ductVAV terminals
a Trane Engineers Newsletter Live online program
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Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
35
Alternative System DesignsAlternative System Designs Single-zone VAV Single-zone VAV
Demand-controlled ventilation
Humidity control
Dedicated outdoor-air unit in j ti ith ftconjunction with rooftop
Optimized System ControlsSystem Controls
E i Energy-saving strategies for rooftop VAV systems
a Trane Engineers Newsletter Live online program
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© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
36
Airside EconomizerAirside Economizermech
coolingheatingintegrated
econmodulated
econ coolingheating econ
outdoorair
econ
inta
ke f
low
, %
100
mech clg
heatingcapacity
0
OA
i
OA temperaturecold hot
min
mech clgcapacity
High-Limit ShutoffHigh-Limit ShutoffDisable econDisable econ Enable econEnable econ(minimum OA)(minimum OA) (up to 100% OA)(up to 100% OA)(minimum OA)(minimum OA) (up to 100% OA)(up to 100% OA)
Control typeControl type when OA is:when OA is: when OA is:when OA is:
Fixed dry bulb Warmer than Cooler thanfixed setting fixed setting
Fixed enthalpy Higher enthalpy Lower enthalpy than fixed setting than fixed setting
Differential Higher enthalpy Lower enthalpyenthalpy than RA than RA
a Trane Engineers Newsletter Live online program
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© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
37
VAV system (Cincinnati, Ohio)
Energy ComparisonVAV system (Cincinnati, Ohio)
Energy Comparison,
100
10%9%11%
en
erg
y c
on
sum
pti
on
,%
of
base
85
90
95
none 65°Ffixed DB
28Btu/lbfixed h
differentialenthalpy
HV
AC
e
75
80
Optimal StartOptimal Start
systemon
systemoff
occupied hours
occupiedheating
setpoint
unoccupied
optimalstart
6 AM noon 6 PMmid mid
occupied hoursunoccupiedheating
setpoint
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© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
38
Optimal StopOptimal Stop
systemon
systemoff
occupied hours
optimalstop
drift below
occupiedheating
setpoint
unoccupied
6 AM noon 6 PMmid mid
occupied hours drift belowoccupiedsetpoint
unoccupiedheating
setpoint
Supply Fan ControlSupply Fan Control
supplyfan
~2/3 distancedown main duct PP
VAV boxes
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Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
39
static
Fan Pressure OptimizationFan Pressure Optimization
VAV boxes
pressuresensor
PPsupplyfan
communicating BAS
VAV boxes
Part-Load Energy SavingsPart-Load Energy Savings
tati
c p
ress
ure
duct static pressure control
airflow
st
fan-pressure optimization
a Trane Engineers Newsletter Live online program
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© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
40
Reduced Risk of Fan SurgeReduced Risk of Fan Surgeta
tic
pre
ssu
re
duct static pressure control
surge
airflow
st
fan-pressure optimization
SA Temperature ResetSA Temperature Reset Decreases compressor energy Decreases compressor energy
Higher suction pressure
More hours of modulated economizing
Decreases reheat energy
I f Increases fan energy
Raises humidity level in the zones
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© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
41
To Reset or Not to ResetTo Reset or Not to Reset Mild climates Hot climates or Mild climates
(many hours when OADB < 60°F)
Minimum VAV airflow settings > 30%
Efficient air
Hot climates or humid climates(few hours when OADB < 60°F)
Efficient part-load fan modulation
Inefficient air Efficient air distribution system
Interior zones with varying cooling loads
Inefficient air distribution system
Zones with near-constant cooling loads
SAT reset based on OA temperature
ExampleSAT reset based on OA temperature
Example
°F 61
mp
era
ture
setp
oin
t, 61
60
59
58
57
56
55 60 6550 807570outdoor dry-bulb temperature, °F
SA
tem 56
55
a Trane Engineers Newsletter Live online program
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© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
42
SAT reset based on “critical” zone
ExampleSAT reset based on “critical” zone
ExampleBAS
lounge restroom
storage office
vestibule corridor
TT
TTTT
TTTTTT
office conference rm computer roomreception area elev
ators TTTTTTTT
SAT reset Application ConsiderationsSAT reset Application Considerations Design zones with nearly-constant g y
cooling loads for warmer (reset) SAT
May require larger VAV terminals and ductwork
Allows SAT reset while still providing needed cooling to these zones
Design an efficient air distribution system
Employ fan-pressure optimization
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
43
SAT resetApplication ConsiderationsSAT resetApplication Considerations Analyze the systemy y
Will compressor and reheat energy savings outweigh additional fan energy?
Consider impact on zone humidity
Di bl t h h id t id Disable reset when humid outside
Use a humidity sensor to disable reset when zone humidity gets too high
ASHRAE 62.1-2004
Dynamic Reset of OAASHRAE 62.1-2004
Dynamic Reset of OA May reset OA intake flow or zone OA May reset OA intake flow or zone OA
flow in response to:
Variations in zone population (DCV)
Variations in ventilation efficiency due to changes in airflow (ventilation reset)( )
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
44
ventilation optimization
Zone Level: DCVventilation optimization
Zone Level: DCVBAS
lounge restroom
storage office
vestibule corridor
CO2
mechroom
OCCAHU
TOD
office conference rm computer roomreception area elev
ators
CO2OCC
ventilation optimization
System Level: Vent Resetventilation optimization
System Level: Vent Resetrooftop unitwith controls
OA
SA RA
• Reset outdoor airflow (Vot)
CO2 CO2OCC OCC
• Required ventilation (Voz)• Actual primary airflow (Vpz)
DDC/VAV terminalscommunicating BAS• New OA setpoint (Vot)
a Trane Engineers Newsletter Live online program
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© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
45
ventilation optimization
DCV and Vent Resetventilation optimization
DCV and Vent Reset Assures each zone receives proper Assures each zone receives proper
ventilation without requiring a CO2sensor in every zone
Enables documentation of actual ventilation system performance
S t l l til ti t System-level ventilation reset equations are defined by ASHRAE 62
Optimized System ControlsOptimized System Controls Economizer Economizer
Optimal stop and start
Fan pressure optimization
Supply air temperature reset
Demand controlled ventilation and ventilation reset
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
46
AnalysisAnalysis
E i Energy-saving strategies for rooftop VAV systems
Building Analysis ToolsBuilding Analysis ToolsTRACE™ 700TRACE 700HVAC load design and analysis software
Comprehensive energy andeconomic analysis for virtuallyany building
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
47
rooftop VAV system
Example Analysisrooftop VAV system
Example Analysis“Optimized” Systemp y
Optimal start
SA temperature reset
Ventilation optimization
Fan-pressure optimization
Total-energy wheel Total energy wheel
Comparative enthalpy economizer
Parallel FPVAV (perimeter zones)
rooftop VAV system
HVAC Energy Savingsrooftop VAV system
HVAC Energy Savings100
n,
40
60
80
en
erg
y c
on
sum
pti
on
% o
f b
ase
MinneapolisLos AngelesAtlanta0
20
HV
AC
e
optimized systembase system
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
48
rooftop VAV system
HVAC Energy Savingsrooftop VAV system
HVAC Energy Savings100
n,
40
60
80
en
erg
y c
on
sum
pti
on
% o
f b
ase
MinneapolisLos AngelesAtlanta0
20
HV
AC
e
optimized systemcomplies with 90.1 and 62
Keep the system working properlyworking properly
E i Energy-saving strategies for rooftop VAV systems
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
49
Proper MaintenanceProper Maintenance Periodic maintenance enhances Periodic maintenance enhances
unit performance Always perform airside maintenance first
Inspect air filters regularly,clean or replace as necessary
0.1 inch of additional static pressure pincreases supply motor kW by 7%
Inspect condensate drains and traps whenever filters are inspected, clean as needed
Proper MaintenanceProper Maintenance Periodic maintenance enhances Periodic maintenance enhances
unit performance Inspect fresh- and return-air
damper mechanisms
Clean blades as necessary
Verify all damper linkages move freelyy p g y
Check supply/relief fan motor and shaft bearings, lubricate, repair, or replace as necessary
a Trane Engineers Newsletter Live online program
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© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
50
Proper MaintenanceProper Maintenance Periodic maintenance enhances Periodic maintenance enhances
unit performance Inspect evaporator and condenser coils
for dirt buildup, clean as needed
Make sure that condenser fans rotate freely, check bearings for wear
Verify all condenser fan mountings are secure
Proper MaintenanceProper Maintenance Periodic maintenance enhances Periodic maintenance enhances
unit performance #1: Improper refrigerant charge
Overcharging decreases superheat and increases subcooling
10% overcharge can increase gcompressor kW by approximately 3.5% at design conditions
a Trane Engineers Newsletter Live online program
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© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
51
Proper MaintenanceProper Maintenance Periodic maintenance enhances Periodic maintenance enhances
unit performance #1: Improper refrigerant charge
Undercharging increases superheat and decreases subcooling… resulting in capacity loss
Always charge according to manufacturers recommendations, and instructions
Answers toYour QuestionsYour Questions
E i
This concludes theAmerican Institute of Architects Continuing Education System Program
Energy-saving strategies for rooftop VAV systems
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
52
Energy-efficient rooftop VAV systemsEnergy-efficient rooftop VAV systems
Equipment configuration strategies Equipment configuration strategies
Alternative system designs
Optimized system controls
Analysis
Maintenance
references for this broadcast
Where to Learn Morereferences for this broadcast
Where to Learn More
www.trane.com/engineersnewsletter
a Trane Engineers Newsletter Live online program
Energy-Saving Strategies for Rooftop VAV Systems
© 2010 Trane a business of Ingersoll Rand. All rights reserved
Trane, in proposing these system design and application concepts, assumes no responsibility for the performance or desirability of any resulting system design. Design of the HVAC system is the prerogative and responsibility of the engineering professional.
53
watch past programs
ENL Archiveswatch past programs
ENL ArchivesInsightful topics on HVAC system design:design:
Chilled-water plants Air distribution Refrigerant-to-air systems Control strategies Industry standards and LEED Energy and the environment Acoustics Ventilation Dehumidification
www.trane.com/ENL
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2007 ENL Broadcastsmark your calendar
2007 ENL Broadcasts Feb 21 Waterside heat recovery Feb 21 Waterside heat recovery
Sep 12 Humidity control
Nov 14 LEED™ case studies
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Bibliography
Industry Standards and Handbooks Energy Saving Strategies for Rooftop VAV Systems
American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE). ANSI/ASHRAE IESNA Standard 90.1-2004: Energy Standard for Buildings Except Low-Rise Residential Buildings. Available at <http://xp20.ashrae.org/ frame.asp?standards/std90.html>
American Society of Heating, Refrigerating and Air Conditioning Engineers, Inc. (ASHRAE). Standard 90.1-2004 User’s Manual. Available at <http://www.ashrae.org>
American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE). ANSI/ASHRAE Standard 62.1-2004: Ventilation for Acceptable Indoor Air Quality. Available at <http://www.realread.com/prst/pageview/browse.cgi?book=1931862672>
American Society of Heating, Refrigerating and Air Conditioning Engineers, Inc. (ASHRAE). Standard 62.1-2004 User’s Manual. Available at <http://www.ashrae.org>
Trane Publications Guckelberger, D. “Brushless DC Motors: Setting a New Standard for
Efficiency.” Engineers Newsletter 33-4 (2004). Available at <http://www.trane.com/commercial/library/vol33_4/admapn013en_1204.pdf>
Murphy, J. “CO2-Based Demand-Controlled Ventilation.” Engineers Newsletter 34-5 (2005). Available at <http://www.trane.com/commercial/library/vol34_5/admapn017en_1005.pdf>
Murphy, J. “Energy Saving Control Strategies in Rooftop VAV Systems.” Engineers Newsletter 35-4 (2006). Available at <https://www.trane.com/Commercial/Navigation/Files/Pdf/670/admapn022en_1006.pdf>
Murphy, J. and B. Bradley. Air-to-Air Energy Recovery in HVAC Systems, application manual SYS-APM003-EN, July 2002. Available at <http://www.trane.com/bookstore>
Murphy, J. and B. Bradley. Dehumidification in HVAC Systems, application manual SYS-APM004-EN, July 2002. Available at <http://www.trane.com/bookstore>
Solberg, P. “Hot Gas Bypass: Blessing or Curse?” Engineers Newsletter 32-2 (2003). Available at <http://www.trane.com/commercial/library/vol32_2/ADM_APN007_EN_0503.pdf>
bibliography
Trane Engineers Newsletter Live satellite broadcast
Bibliography
bibliography
Trane Publications (continued)
Stanke, D. “Commercial Building Pressurization.” Engineers Newsletter 31-2 (2002), Available at <http://www.trane.com/commercial/library/vol31_2/ADM_APN003_EN_040302.pdf>
Stanke, D. “Keeping Cool with Outdoor Air: Airside Economizers.” Engineers Newsletter 35-2 (2006), Available at <http://www.trane.com/Commercial/Navigation/Files/Pdf/6/admapn020en_0406.pdf>
Stanke, D. “VAV System Optimization: Critical Zone Reset.” Engineers Newsletter 20-2 (1991), Available at <http://www.trane.com/commercial/library/EN20-2.pdf>
Trane Analysis Software
Trane Air-Conditioning and Economics (TRACE™ 700), Available at <http://www.trane.com/commercial/equipment/ProductDetails.aspx?prod=150>