Compliance (NECB 2017) Part (3) Building envelope
Transcript of Compliance (NECB 2017) Part (3) Building envelope
Classification: Protected A
Energy CodeCompliance (NECB 2017)Part (3) Building envelope
Prepared & Presented By: Nabil Habashy, Energy Code Specialist, AMA
Classification: Protected A
NECB PresentationsObjectives: NECB intent.
NECB applications.
Part 3 – Building envelope. General requirements:
Above ground Building Envelope /Walls/ Floors/Roofs.
Thermal characteristics of Fenestration.
Thermal characteristics of Doors and Access Hatches.
Thermal characteristics for walls/floors/ Roofs in contact with the ground.
Air Leakage
Trade-off Simple Trade-off
Classification: Protected A
NECB IntentNECB 2017 is an objective based code
NECB 2017 intent:
To limit the negative impact of building design and construction on the environment (OE Environment)
OE1.1 excess use of energy.
Code NECB ABC/NBC
Requirements Power demand of ventilation fan Ventilation flow rates
Classification: Protected A
1.1.1.1. Application of this Code – NECB 20171) Except as provided in Sentence (2), this Code applies to the design and construction of all newbuildings described in Sentence 1.3.3.2.(1) of Division A of the NBC and to additions. (See Note A-1.1.1.1.(1).)2) This Code does not apply to farm buildings.
NECB Application
Classification: Protected A
NECB ApplicationNBC, 2019 (AB edition)1.3.3.2. Application of Parts 3, 4, 5 and 61) Parts 3, 4, 5, and 6 of Division B apply to all buildings described in Article 1.1.1.1.anda) classified as post-disaster buildings,b) used for major occupancies classified asi) Group A, assembly occupancies,ii) Group B, care, treatment or detention occupancies, oriii) Group F, Division 1, high-hazard industrial occupancies.
Classification: Protected A
NECB ApplicationSummary Any Building under part 3 Buildings greater than 600m2 or exceeding 3 storeysGroup C, D, E, F2, and F3 All occupancies of (Group A, B, and F1) Buildings Outside the scope of section (9.36) . • Group D, E or F3 whose combined total floor area > 300m2• F2 occupancies
Classification: Protected A
Part 3: Building Envelope1.1.2.1. ComplianceCompliance Paths:• Prescriptive path –cookbook• Trade-off path
• Simple trade-off • Detailed trade-off
• Performance path – whole building modeling
Classification: Protected A
Part 3: Building EnvelopeGeneral requirements:
Calculation rules & StandardsProtection of insulation materialsContinuity of insulationSpaces heated to different temperature (>10oc.)Allowable fenestration and door area
Above ground building envelopeVestibuleWalls/Roofs/Floors thermal characteristics. FenestrationDoor and access hatch
Building assemblies in contact with the groundWalls/Roofs/Floors thermal characteristics
Air LeakageOpaque/fenestration/doors/fire place doors.
Classification: Protected A
Part 3: Building Envelope• Part 3 is concerned with the transfer of heat and
air through the building envelope• The building envelope is the collection of
components that separate conditioned space from unconditioned space, exterior air, or the ground.
Classification: Protected A
Part 3: Building Envelope3.1.1.5. Thermal Characteristics of Building AssembliesThermal characteristics for MaterialsDetermined through the following standards:
• Product standard listed in NBC• ASTM C 177• ASTM C 518
Calculations shall be carried out • at an average temperature of 24±2°C and under
a temperature difference of 22±2°C.
Classification: Protected A
Part 3: Building Envelope3.1.1.5. Thermal Characteristics of Building AssembliesThermal transmittance of Fenestration & DoorsDetermined through the following standards:
• CSA A440.2/A440.3, “Fenestration Energy performance/User Guide to CSA A440.2-14, Fenestration Energy Performance,” or
• NFRC 100, “Determining Fenestration Product U-factors.”
• If outside the scope of the above standards:• ASHRAE Handbook – Fundamentals or• Tested to ASTM C 1363
Classification: Protected A
Part 3: Building Envelope3.1.1.5. Thermal Characteristics of Building AssembliesR-Effective calculations for Building AssembliesNECB lists 3 methods1. Calculations
• ASHRAE Fundamentals • ISO 14683 • BC Hydro - Notes• ASHRAE Research Project RP-1365 - Notes
2. 2D or 3D thermal modeling or3. Laboratory testing ASTM C 1363
Classification: Protected A
Part 3: Building Envelope3.1.1.6. Fenestration/Door Calculations • Calculation includes rough opening in the walls• Gross wall area doesn’t include parapets,
projected fins, ornamentation and appendages.• For allowable Skylight area, gross roof area shall
be the insulated roof area including skylights.
Classification: Protected A
Part 3: Building EnvelopeCalculation of Overall Thermal TransmittanceArticle 3.1.1.7.Added more clarity; the effect of thermal bridging should be accounted for in RSI effective calculations.1. Repetitive structural members.
Secondary Structural Members 2. Major structure penetrations.3. Junctions in components and assemblies.4. Secondary structure members.5. Fasteners need not be taken into account.
Classification: Protected A
THERMAL BRIDGING SOLUTIONSFOR CLADDING ATTACHMENTS
Secondary Structural Members
Classification: Protected A
Part 3: Building Envelope3.1.1.7. Overall Calculations • Calculations to include the effect of thermal bridging
• Studs, joists, lintels, sills and plates, etc.• Beam, girders, curbs, balconies, floor, etc.• Roof to wall junctions, corners, spandrels, etc.• Girts, purlins, hat channels, U-channels, shelf
angles, etc.
• Enclosed unconditioned spaces, e.g. sun porch, enclosed veranda, enclosure considered to have U-Value of 6.25 W/(m2·K).
Classification: Protected A
Part 3: Building Envelope3.1.1.7. Overall Thermal TransmittancePipes, ducts, equipment with through-the-wall venting, packaged terminal air conditioners or heat pumps need not be taken into account.• The impact of penetrations described in Sentence
3.1.1.7.(2) on the overall thermal transmittance is difficult to assess but is considered to be negligible if the insulation is installed tight to the penetration.
Classification: Protected A
Part 3: Building Envelope3.1.1.7. Overall Calculations The effect of thermal bridging shall be considered for• The junctions between the following building
envelope materials, components, and assemblies:• i) glazing assemblies,• ii) spandrels,• iii) parapets,• iv) roof-to-wall junctions,• v) corners, and• vi) edges of walls or floors, and
Classification: Protected A
Part 3: Building Envelope3.2.1.1 Protection of Insulation MaterialsThe building envelope shall be designed to avoidincreasing the overall thermal transmittance of the insulation material due toa) air leakage or convection,b) wetting, orc) moisture bypassing the plane of thermal resistance.
Where any of the above conditions occur, their effecton the overall thermal transmittance of the insulation material shall be calculated in accordance with Article 3.1.1.5.(options include lab test)
Classification: Protected A
Part 3: Building Envelope3.2.1.2 Continuity of InsulationPipes, ducts, conduits, cabinets, panels, or recessed heaters, parallel to the building envelope.
• The overall thermal transmittance of the building envelope shall not be increased.
Joints such as expansion or construction joints or joints between walls and doors or fenestration.
• Insulated in a manner that provides continuity across such joints. (See Note A-3.2.1.2.(2).)
This means that there should be no gap in the insulation between the two components. An obvious application is insulating the space between a window or door frame and the rough framing members.
Classification: Protected A
Part 3: Building Envelope3.2.1.3 Spaces Heated to Different Temperatures
The building envelope also includes the separation between separate interior spaces that are intended to be conditioned at temperatures differing by >10oC at design conditions, such as:
• Cold storage warehouses to an office • Swimming pools to ice rinks • Offices to warehouses with minimal heat
Ice Rink14oC
Swimming Pool25oC
Classification: Protected A
Part 3: Building EnvelopeAllowable fenestration and door area.Varies from 20% to 40%, based on HDD of location•FDWR = 0.40 for HDD < 4000•FDWR ≤ (2000 - 0.2HDD)/3000 for 4000 ≤ HDD ≤ 7000•FDWR = 0.20 for HDD > 7000
•FDWR = 0.40 for HDD ≤ 4000•FDWR =(2000 - 0.2 HDD)/3000 for 4000 < HDD <7000•FDWR = 0.20 for HDD ≥ 7000
Skylights – maximum 5% 2% of gross roof areaEdmonton -approx. 32.5%Calgary -approx. 33.3%
Classification: Protected A
Part 3: Building EnvelopeVestibules:Required at all “main” entries (some exceptions)
A vestibule is not required for an exterior door :• Revolving door,• Vehicular movement or material handling,• Service, emergency exit, or stairwell exit door,• Seasonal use door, such as a door leading to a patio,• Dwelling units,• Retail space less than 200 m2 in area or • Space less than 150 m2 for other uses, or• Building less than 5 storeys in building height & fewer
than 3500 HDD
Classification: Protected A
Part 3: Building EnvelopeAbove-ground Opaque Building Assemblies Thermal Transmittance
NECB 2011/2015 Roofs are U 0.162 (R-35)NECB 2017 Roofs are U 0.138 (R-41)
Classification: Protected A
Part 3: Building EnvelopeAbove-ground Opaque Building Assemblies Semi-heated buildings:(1.2.1.2.) A semi-heated building is considered to be a building with a design set-point temperature of less than 15°C.
Zone 7A : R-27 Zone 6: R-24
Classification: Protected A
Part 3: Building EnvelopeAbove-ground Opaque Building Assemblies Considerations:
Where the top of a foundation wall is less than 0.4 m aboveground level, Table 3.2.3.1. (below ground/contact with ground) is to be used.
Where radiant heating cables or heating or cooling pipes or membranes are embedded in the surface of an above-ground opaque building assembly, thermal transmittance shall not be greater than 80%
Example: Roofs 7B : U-Value = 0.162 (R35)Roofs with Embedded pipes 7B: Maximum U-Value = 0.162x 80/100 = 0.1296 (R43.7)
To counteract the increased heat loss that occurs due to the increased temperature difference between the interior and exterior surfaces
Classification: Protected A
Part 3: Building EnvelopeFenestration thermal transmittance:
NECB 2011/2015 Zone 7B are 2.2
Classification: Protected A
Part 3: Building EnvelopeDoors and Access Hatches Doors thermal transmittance:
Doors of area less then 2% and U-Value is not greater than U(4.4) are exemptedAccess Hatches U-Value (nominal insulation) not more than U(1.3)
Following doors are exempted:Storm doors, automatic sliding glass doors, revolving doors, and fire shuttersBut these glazed areas must be factored in as part of the area of fenestration
Classification: Protected A
Part 3: Building EnvelopeWalls in Contact with the Ground Thermal transmittance:
• Insulation on walls to extend 2.4 m or bottom of wall whichever is less.
• Embedded radiant heating cables or heating or cooling pipes or membrane, thermal transmittance shall not be greater than 80% ( means more insulation is required)
• Where the top of the footing is less than 0.6 m below ground level, insulation shall be placed on the top or bottom surface of the floor not less than 1.2 m from the perimeter
Classification: Protected A
Part 3: Building EnvelopeWalls in Contact with the Ground Thermal transmittance:
If Footing is less than 0.6 m below ground level
Not less than 1.2 mfrom the perimeter(top or bottom of the floor)
Insulation on walls to extend 2.4 m or bottom of wall
Classification: Protected A
Part 3: Building EnvelopeRoofs in Contact with the Ground Thermal transmittance:
• Roofs that are part of the building envelope and are less than 1.2 m below the exterior ground level shall be not greater than that shown in Table 3.2.3.1
3.2.3.1. Thermal Transmittance of Building Assemblies in Contact with the Ground
Classification: Protected A
Part 3: Building EnvelopeFloors in Contact with the Ground:
If no insulation required U-values for floors separating conditioned space from the ground that are less than 0.6 m below grade shall be not greater than that shown in Table 3.2.3.1. ( 0.757 for 1.2 meters)• *Extend vertically around the perimeter of the floor.If insulation required
(No embedded heating/cooling ):• On their top or bottom surface for a distance of not less than
1.2 m from their perimeter or over their full area.• *Extend vertically around the perimeter of the floor.
(with embedded heating/cooling):• Over their full area.• *Extend vertically around the perimeter of the floor.
*Or external insulation extends down to the bottom ofThe floor
Classification: Protected A
New in NECB 2017
Lowered U value for Roofs (increased R values); for all Zones
e.g. Zone 7A
NECB 2011 NECB 2015 NECB 2017
Walls 0.21 0.21 0.21
Roofs 0.162 0.162 RSI 6.17 (R35) 0.138 RSI 7.24 (R41)
Floors 0.162 0.162 0.162
Part 3: Building Envelope
No change for Below ground assemblies.
Classification: Protected A
New in NECB 2017
Lowered U value for Fenestration and Doors; (increased R values) for all Zones
Zone 7ANECB 2011 NECB 2015 NECB 2017
ALL 2.2 2.2 (RSI 0.45 –R 2.56 ) 1.9 (RSI 0.52 – R 2.95)
Doors 2.2 2.2 (RSI 0.45 –R 2.56 ) 1.9 (RSI 0.52 – R 2.95)
Part 3: Building Envelope
Classification: Protected A
Part 3: Building Envelope3.2.4. Air LeakageAir Barrier for Building assemblies :An air leakage rate no greater than 0.2 L/(s·m2) at a pressure differential of 75 Pa.Tested to:CAN/ULC-S742, “Air Barrier Assemblies – Specification,”
OrASTM E 2357, “Determining Air Leakage of Air Barrier Assemblies,”Note:If tested under ASTM E 23571-in-50 hourly wind pressures do not exceed 0.65 kPa,andThe air barrier assembly is installed on the warm side.
Classification: Protected A
Part 3: Building Envelope3.2.4. Air LeakageAir Barrier for Fenestration:
Metal & Glass curtain walls:An air leakage rate no greater than 0.2 L/(s·m2) when tested in accordance with ASTM E 283, at a pressure differential of 75 Pa.
Fixed windows and skylights:An air leakage rate no greater than 0.2 L/(s·m2) at a pressure differential of 75 Pa.when tested in accordance with AAMA/WDMA/CSA 101/I.S.2/A440, “NAFS – North American Fenestration Standard/Specification for Windows, Doors, and Skylights,”
Classification: Protected A
Part 3: Building Envelope3.2.4. Air LeakageAir Barrier for Fenestration:
Operable windows and skylightsAir leakage rate not greater than 0.5 L/(s·m2) when tested in accordance with AAMA/WDMA/CSA 101/I.S.2/A440, “NAFS – North American Fenestration Standard/Specification for Windows, Doors, and Skylights,” at a pressure differential of 75 Pa.
Classification: Protected A
Part 3: Building Envelope3.2.4. Air LeakageAir Barrier for Doors:Exterior Doors:Air leakage rate not greater than 0.50 L/(s·m2) when tested inaccordance with ASTM E 283, at a pressure differential of 75 Pa.
Revolving doors, automatic commercial sliding doors (including theirrespective fixed sections), overhead doors.Air leakage rate not greater than 5.0 L/(s·m2) when tested as a complete assembly in accordance with ASTM E 283 at a pressure differential of 75 Pa.
Classification: Protected A
Part 3: Building Envelope3.2.4. Air LeakageAir Barrier for Doors:Main entry exterior doors Are permitted to have an air leakage rate not greater than 5.0 L/(s·m²) when tested as a complete assembly in accordance with ASTM E 283, at a pressure differential of 75 Pa, providedThe total area of such doors does not exceed 2% of the gross wall area
Loading docks that interface with truck boxes Shall have weather seals that seal the truck box to the building.
Fireplace Doors Shall be equipped with doors or enclosures to restrict air movement through the chimney when the fireplace is not in use.
Classification: Protected A
Part 3: Building EnvelopeTrade-off rules:• For above-ground assemblies and to the allowable fenestration
and door areas.• Doesn’t apply to addition or semi-heated buildings.• Vertical portions are only permitted to be traded off against
vertical portions.• Horizontal portions are only permitted to be traded off against
Horizontal portions.
Make Sure:• For embedded assemblies that have radiant heating, cooling
pipes, membrane, shall have an overall thermal transmittance no greater than 80%
• Other high performance construction technique are not permitted to be included in trade-off calculation.
Classification: Protected A
Thank you
QuestionsE-mail : [email protected]
Phone :1.866.421.6929
PLEASE VISIT https://www.alberta.ca/energy-codes.aspx