adoption and compliance with energy codes: ashrae 90.1 and necb

Lessons Learned from Bri.sh Columbia

Adop%on and Compliance with Energy Codes: ASHRAE 90.1 and NECB

!   Graham Finch, MASc, P.Eng Principal, Building Science Research Engineer RDH Building Engineering Ltd. Vancouver, BC

RCIC 2013 Edmonton – May 1, 2013

Presenta%on Outline

!   Energy Efficiency Requirements for Part 3 Buildings in BC

!   Enforcement & Compliance !   ASHRAE 90.1 Overview & Lessons Learned !   NECB 2011 Similari.es & Differences

!   In the Past: !  City of Vancouver (VBBL 2007), ASHRAE 90.1-‐2007

•  ASHRAE in code for more than a decade •  Enforcement boosted in past few years (checklists)

!  Rest of BC (BCBC 2006), ASHRAE 90.1-‐2004 •  ASHRAE added in 2008 •  Enforcement up to the authority having jurisdic.on (AHJ)

!  Window Performance – BC Energy Efficiency Act (2009) !   LEED – ASHRAE 90.1-‐2007 PRM or MNECB 1997

!   Upcoming: !  City of Vancouver (VBBL 2013), ASHRAE 90.1-‐2010 or NECB 2011 !  Rest of BC (BCBC 2012+), ASHRAE 90.1-‐2010 or NECB 2011 !  Window Performance – BC Energy Efficiency Act & Within Code

Overview of Energy Efficiency Requirements in BC

!   City of Vancouver released new building permit & occupancy documenta.on process to improve compliance with ASHRAE 90.1

!   Checklists signed off by each registered professional (mechanical, electrical, enclosure/architect) and coordina.ng professional

!   Effec.ve R-‐values on drawings/ “Insula.on schedules”

!   Energy model outputs

Enforcement & Compliance

!   ASHRAE 90.1 “Energy Standard for Buildings Except Low-‐Rise Residen.al Buildings”

!   Compliance involves mee.ng energy efficiency requirements in all sec.ons: !   5 – Building Envelope (Enclosure) !   6 – Hea.ng, Ven.la.ng, and Air

Condi.oning !   7 – Service Water Hea.ng !   8 – Power !   9 – Ligh.ng !   10 – Other Equipment

ASHRAE 90.1 Overview

!   Alternate compliance op.ons within each sec.on !  Prescrip.ve !   Trade-‐offs !   Energy Simula.on

!   Involves several disciplines with professional engineers coordina.ng their efforts plus one coordina.ng professional taking overall responsibility

!   Chosen compliance path has implica.ons for building design

ASHRAE 90.1 Overview

!  Mandatory Provisions (Sec.on 5.4) !   Insula.on

•  Protec.on, Ra.ng, Labeling, Installa.on !   Fenestra.on & Doors

•  NFRC cer.fica.on, air.ghtness, labels !  Air Leakage

•  “con.nuous air barrier”, prescrip.ve sealing, Ves.bules, weather seals

!   Prescrip.ve Compliance Path (Sec.on 5.5) !  All components must meet prescrip.ve tables, maximum 40%

glazing area

!   Building Envelope Trade-‐off Compliance Path (Sec.on 5.6) !   Trade-‐off enclosure components using ASHRAE ENVStd somware

!   Energy Cost Budget (ECB) Path (Sec.on 11) !  Whole building energy cost simula.on & tradeoffs ($ not kWh)

ASHRAE 90.1 Building Enclosure Compliance

!   Compliance pathway is heavily influenced by building enclosure design : !  Window to wall ra.o

•  Maximum 40% for Prescrip.ve Op.on •  No limit for BE Trade-‐off op.on or ECB

!  Minimum assembly and component R-‐values •  Prescrip.ve Op.on -‐ difficult to comply with thermal bridging •  BE Trade-‐off Op.on – detailed area weighted U-‐value calcula.ons input into ENVStd somware

•  Energy Cost Budget (ECB) -‐ detailed area weighted U-‐value calcula.ons input into energy model

!  Changes to design during tendering and construc.on can erode final compliance – need for “factor of safety”

ASHRAE 90.1 Building Enclosure Compliance

!   All building envelope assemblies (including details) must meet Table 5.5 thermal requirements (by climate zone) !   Opaque Walls/Roof: Assembly Maximum U-‐value (Minimum

effec.ve R-‐value) or Insula%on Minimum R-‐value (nominal insula.on)

!  Windows/Doors/Skylights: Maximum U-‐value and SHGC restric.ons

!  Maximum of 40% window to wall ra.o !  Maximum of 5% skylight to roof ra.o !   Basic area take-‐offs only necessary to verify window-‐wall

ra.o (and skylight to roof ra.o) !   Can be difficult to comply with for many common building

designs

Prescrip%ve Building Envelope Op%on

!   Two alternate ways to meet prescrip.ve requirements !   Assembly Maximum U-‐value (Minimum R-‐value)

•  Accounts for all materials in assembly including air-‐films •  Easiest method to comply with and greatest flexibility in design

!   Insula.on Minimum R-‐value •  Prescrip.ve rated R-‐value of installed insula.on (nominal minimum) •  Many assemblies prescrip.vely require con.nuous insula.on (ci)

Prescrip%ve Building Envelope R-‐value Tables

!   Only screws/nails are considered “fasteners” (or adhesives) !  Where any con.nuous or discon.nuous framing (girts,

studs, clips, brick .es, shelf angles, slab edges) penetrate through the insula.on – it is not considered c.i.

!   Note: Con.nuous insula.on is not necessarily a mandatory requirement for prescrip.ve compliance (high enough R-‐values can be achieved without true ci)

Con%nuous Insula%on (ci)

!   Nominal R-‐values = Rated R-‐values of insula.on which do not include impacts of how they are installed !   For example R-‐20 baq insula.on or

R-‐10 foam insula.on !   Effec.ve R-‐values or Real R-‐values =

Calculated R-‐values of assemblies/details which include impacts of installa.on and thermal bridges !   For example nominal R-‐20 baqs

within steel studs becoming ~R-‐9 effec.ve, or in wood studs ~R-‐15

Nominal vs Effec%ve R-‐values

!   Thermal bridging occurs when a more conduc.ve material (e.g. aluminum, steel, concrete, wood etc.) provides a path for heat to flow such that it bypasses a less conduc.ve material (insula.on)

!   The bypassing “bridging” of the less conduc.ve material significantly reduces its effec.veness as an insulator

!   Examples: !   Wood framing (studs, plates) in insulated wall !   Steel framing in insulated wall !   Conduc.ve cladding aqachments through insula.on

(metal girts, clips, anchors, screws etc) !   Concrete slab edge (balcony, exposed slab edge)

through a wall !   Window frames and windows themselves

Thermal Bridging

!   Effec.ve R-‐values account for thermal bridges and represent actual heat flow through enclosure assemblies and details !   Heat flow finds the path of least resistance !   Dispropor.onate amount of heat flow

occurs through thermal bridges !   Omen adding more/thicker insula.on can’t

help !   Required for almost all energy and building

code calcula.ons !   Energy code compliance has historically

focused on assembly R-‐values – however more importance is being placed on details and interfaces & whole building impacts of thermal bridges

Why Thermal Bridging is Important

ASHRAE/NECB/NBC Climate Zone Divisions

•  >7000 HDD

•  6000 to 6999 HDD

•  5000 to 5999 HDD

•  4000 to 4999 HDD

•  3000 to 3999 HDD

•  < 3000 HDD

Wall, Roof & Window Requirements for Alberta (Part 3)

Climate Zone

Wall – Above Grade: Minimum R-‐value (IP)

Roof – Flat or Sloped: Minimum R-‐value (IP)

Window: Max. U-‐value (IP)

8 31.0 40.0 0.28

7B 27.0 35.0 0.39

7A 27.0 35.0 0.39

6 23.0 31.0 0.39

NEC

B 2011

ASHR

AE 90.1-‐2010 –

Reside

n%al Building Climate

Zone Wall (Mass, Wood, Steel): Min R-‐value

Roof (A]c, Cathedral/Flat): Min R-‐value

Window (Alum, PVC/FG):Max. U-‐value

8 19.2, 27.8, 27.0 47.6, 20.8 0.45, 0.35

7B 14.1, 19.6, 23.8 37.0, 20.8 0.45, 0.35

7A 14.1, 19.6, 23.8 37.0, 20.8 0.45, 0.35

6 12.5, 19.6, 15.6 37,0, 20.8 0.55, 0.35

*7A/7B combined in ASHRAE 90.1

Wall, Roof & Window Requirements for Alberta (Part 9)

Climate Zone

Wall -‐ Above Grade: Minimum R-‐value (IP)

Roof – Flat/Cathedral: Minimum R-‐value (IP)

Roof – A]c: Minimum R-‐value (IP)

Window: Max. U-‐value (IP) / Min. ER

8 21.9 28.5 59.2 0.25 / 29

7B 21.9 28.5 59.2 0.25 / 29

7A 17.5 28.5 59.2 0.28 / 25

6 17.5 26.5 49.2 0.28 / 25

With

out a

HRV

Climate Zone

Wall -‐ Above Grade: Minimum R-‐value (IP)

Roof – Flat/Cathedral: Minimum R-‐value (IP)

Roof – A]c: Minimum R-‐value (IP)

Window: Max. U-‐value (IP) / Min. ER

8 17.5 28.5 59.2 0.25 / 29

7B 17.5 28.5 59.2 0.25 / 29

7A 16.9 28.5 49.2 0.28 / 25

6 16.9 26.5 49.2 0.28 / 25

With

a HRV

For Comparison to NBC 2010 (2012 Update) Sec.on 9.36

Excerpt from 90.1-‐2010 Table 5.5-‐7 (Edmonton, AB)

Building Enclosure Component

Climate Zone 7 – Residen%al Buildings Minimum Assembly

R-‐value c2 ⋅°F⋅ h/Btu

Minimum Insula%on R-‐value

c2 ⋅°F⋅ h/Btu Roof – Insula.on Above Deck R-‐20.8 R-‐20 c.i. Roof – Avc R-‐37.0 R-‐38 Above Grade Wall – Wood-‐Frame R-‐19.6 R-‐13 + 7.5 c.i. Above Grade Wall – Steel Frame R-‐23.8 R-‐13 + 15.6 c.i. Above Grade Wall – Mass R-‐14.1 R-‐15.2 c.i. Below Grade Wall – Concrete R-‐10.9 R-‐10.0 c.i. Windows Maximum Window U-‐value Btu/h·∙m2·∙°F Non Metal Frame (Vinyl, Fibreglass and Wood)

U-‐0.35 (no SHGC requirement)

Metal Framed Windows (Aluminum, Window Wall)


Metal frames (Curtainwall & Storefront)


* c.i. = con)nuous insula)on

!  Window-‐wall ra.os >40% !   Curtain-‐wall or window-‐wall

spandrel panels !   Balconies & exposed slab

edge projec.ons !  Mass concrete walls with

interior insula.on !   Roof parapet, overhang

details, canopies !   Insula.on placed between

steel studs or z-‐girts !   Best suited for simple

buildings

Common Difficul%es in Mee%ng Prescrip%ve Compliance

!   Structural Stud Framing in Taller Mul.-‐Unit Residen.al Buildings


!   Spandrel Panels


ver.cals

!   Cladding Aqachment through Exterior Insula.on – Minimize Thermal Bridging

Solu%ons for Mee%ng Prescrip%ve Compliance

Alternate Cladding Support Comparison

!   Cast-‐in-‐Place Concrete Balcony & Slab Edge Thermal Breaks

Solu%ons for Mee%ng Prescrip%ve Compliance

!   Allows for greater flexibility in architectural design !  Common path for Mul.-‐Unit Residen.al Buildings where more

complex enclosure designs are u.lized

!   Necessary where window-‐wall ra.os exceed 40% and enclosure assemblies/details may not meet minimum prescrip.ve requirements

!   Requires determina.on of effec.ve thermal performance of all enclosure assemblies, details, and components

!   Trade-‐offs made between any enclosure component (i.e. between walls and windows, or walls and roofs etc.)

Building Envelope Trade-‐off Op%on

!   Compliance is assessed by calcula.on of Envelope Performance Factor (EPF) calculated using ASHRAE EnvStd somware !   EPF approximates the total hea.ng and cooling energy associated

with a single square foot of surface. A lower EPF is beqer than a high EPF

!   Overall U-‐value of building enclosure driving factor in EPF plus day-‐ligh.ng and solar-‐heat gain through windows

!   Proposed building enclosure is compared to a minimally prescrip.vely compliant baseline building enclosure !   Baseline building construc.on is iden.cal except that all building

enclosure assemblies meet maximum U-‐value (minimum R-‐value) requirements within each class of construc.on and a 40% window-‐wall ra.o is assumed


!   Step 1: Iden.fy Building “Spaces” !   Step 2: Define “Surfaces” within each Space !   Step 3: Coordinate Surfaces & Assemblies !   Step 4: Summarize Windows/Doors for each surface !   Step 5: Summarize Data and Calculate Areas !   Step 6: Enter Data and run EnvStd Program

Building Envelope Trade-‐off Op%on Process

!  Wall and Roof Areas and U-‐values input into ENVStd Somware by construc.on type, orienta.on and occupancy

!  Window/door areas entered within each of the assemblies

!   Output from ENVStd shows Pass/Fail & No. of EPF Points


Assessing Reasons for Non-‐Compliance

Lower EPF is beqer

Current DesignProposed Base Margin % Difference

Roof 981 1011 30 -‐3%Skylight 0 0 0Exterior Walls and Windows 6552 5753 -‐799 14%Floor 873 779 -‐95 12%Slab 0 0 0Below Grade Wall 0 0 0Daylighting Potential 3478 4140 663 -‐16%Total 11884 11683 -‐201 1.7%

FAILS

Component Area UxA % of Heat LossWindows 10,884 4,898 55.7%Doors 1,093 492 5.6%Wall EW1 8,479 1,495 17.0%Wall EW2 894 147 1.7%Wall EW3 168 26 0.3%Curb and slab edge details 1,585 652 7.4%Floor and Soffit Areas 7,466 622 7.1%Roof and Deck Areas 7,474 460 5.2%TOTAL 38,043 8,791

Overall Effective U-‐Value 0.23Overall Effective R-‐Value 4.33

Impact of Window to Wall Ra%o on Overall Performance

Value of High Performance Windows on ASHRAE Compliance

ASHRAE, Maximum 40% Glazing Area

Non-‐Compliant

Compliant

1. Allows for Higher Window-‐Wall Ra%os

Improve Enclosure R-‐value

!  Whole building energy simula.on considers building envelope plus HVAC, DHW, ligh.ng and power. !   Trade-‐offs allowed between BE and mechanical systems !   Energy cost ($) of proposed building compared to baseline

building (with minimally compliant enclosure and baseline HVAC system)

!   Used where building envelope performance cannot meet BE Trade-‐off or prescrip.ve requirements

!   Requires detailed building envelope R-‐value calcula.ons for energy model input – same level of detail as required for BE Trade-‐off with overall R-‐values

!   ECB energy model is different the LEED PRM energy model

Energy Cost Budget Op%on

!   Energy Cost Budget – depends on $ savings, not necessarily energy !  Bigger benefit to addressing higher cost fuel (omen electricity)

rather than higher energy use (ie gas hea.ng)

!   Common approach for compliance for buildings undergoing LEED or other energy modeling

!  Mechanical systems omen make-‐up for poor enclosure choices – not great from long-‐term or passive approach

!   Allows for most flexibility in design, higher window to wall ra.o, more thermal bridging (to a point)

Trends with Energy Cost Budget Op%on

!   ASHRAE Mandatory Provisions Checklist

!   City of Vancouver Submission Checklist

!   “Insula.on Schedule” and Effec.ve R-‐values on Drawings

!   Comparison of actual vs prescrip.ve R-‐values

!   Energy Modeling outputs

Compliance Documenta%on

!   Na.onal Energy Code of Canada for Buildings (NECB) 2011 replaces MNECB 1997

!   Similar compliance paths to ASHRAE 90.1 – Prescrip.ve, Trade-‐offs, and Energy Modeling !  3 – Building Envelope !  4 – Ligh.ng !  5 – HVAC !  6 – Service Water Hea.ng !  7 – Electrical Power Systems and Motors !  8 – Building Energy Performance Compliance Path

!   Building Envelope: Maximum window to wall ra.o from 40% (HDD <4000) down to 20% (HDD >7000)

!   Energy Consump.on vs Energy Cost

NECB 2011 Similari%es & Differences

ASHRAE 90.1-‐2010 vs NECB 2011

Climate Zone

Wall – Above Grade: Minimum R-‐value (IP)

Roof – Flat or Sloped: Minimum R-‐value (IP)

Window: Max. U-‐value (IP)

8 31.0 40.0 0.28

7B 27.0 35.0 0.39

7A 27.0 35.0 0.39

6 23.0 31.0 0.39

NEC

B 2011

ASHR

AE 90.1-‐2010 –

Reside

n%al Building Climate

Zone Wall (Mass, Wood, Steel): Min R-‐value

Roof (A]c, Cathedral/Flat): Min R-‐value

Window (Alum, PVC/FG):Max. U-‐value

8 19.2, 27.8, 27.0 47.6, 20.8 0.45, 0.35

7B 14.1, 19.6, 23.8 37.0, 20.8 0.45, 0.35

7A 14.1, 19.6, 23.8 37.0, 20.8 0.45, 0.35

6 12.5, 19.6, 15.6 37,0, 20.8 0.55, 0.35

*7A/7B combined in ASHRAE 90.1

!   Builder Insight Bulle.ns & Building Enclosure Design Guides ! www.hpo.bc.ca

!   City of Vancouver Checklists

!   ASHRAE 90.1 User Guides !   NECB 2011 Presenta.ons

For More Informa%on & Assistance

!   Graham Finch, MASc, P.Eng [email protected] 604-‐873-‐1181

Discussion