PERD 079 Project - Task 4 - Review of Work Plan and Selection of Wall Assemblies

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PERD 079 Project - Task 4 - Review of Work Plan and Selection of Wall

Assemblies

P E R D 0 7 9 P r o j e c t – R e p o r t T a s k 4 – R e v i e w

o f W o r k P l a n & S e l e c t i o n o f W a l l A s s e m b l i e s

I R C - R R - 2 5 7

R o u s s e a u , M . Z . ; C o r n i c k , S . M . ; S a i d , M . N . ;

M a r e f , W . ; M a n n i n g , M . M .

M a y 2 0 0 8

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PERD 079 PROJECT: ENGINEERED BUILDING ENVELOPE TO

ACCOMMODATE HIGH PERFORMANCE INSULATION WITH

OUTDOOR/INDOOR CLIMATE EXTREMES

Report Task 4 - Review of Work Plan &

Selection of Wall Assemblies

Report No: 44 B1239.7

M. Z. Rousseau, S. M. Cornick, M. N. Said, W. Maref, M. Manning

National Research Council of Canada

Institute for Research in Construction

Ottawa Ontario Canada

Table of content

Disclaimer ……… 3

Acknowledgements ………. 3

Executive summary ………. 4

Introduction ………. 5

Objective ……….. 5

Methodology ……… 5

Result ………... 6

Review of the work plan ………. 6

Selection of promising wall assemblies ………. 6

Conclusion ……… 15

References ……… 15

Disclaimer

This report includes notes of meetings. The views reported are those expressed by the

participants and do not necessarily reflect the views of the Institute for Research in Construction of the National Research Council Canada.

Acknowledgements

The authors wish to acknowledge the contribution of fellow co-workers on this project as well as the contribution of partners making this project possible.

National Research Council Canada Institute for Research in Construction (NRC-IRC)

William Lei Mike Nicholls Mike Swinton Fitsum Tariku

Canada Mortgage and Housing Corporation (CMHC)

Barry Craig Don Fugler Bill Semple

Natural Resources Canada (NRCan)

Anil Parehk Charles Zaloum

Program for Energy Research and Development (PERD) administered by NRCan

Executive summary

Task 4 of the PERD 079 project aimed at the review of the work plan and the selection of promising wall assemblies for investigation of their hygrothermal, energy and environmental performance, with the project partners. Task 2 activities consisting of the review of literature on innovative energy-efficient construction methods and the consultation of the communities in the 3 territories provided the basis for formulating proposals of promising wall assemblies for

discussion with partners. NRC-IRC organized partners meetings on June 12 and 20th 2007 where a review of the progress in the project and the selection of six wall assemblies took place. These wall assemblies are:

1) a reference wall construction of 2X6 filled with glass fibre batt insulation

2) a 2X6 framing and cavity filled with semi-rigid mineral fibre insulation, with additional insulation in a strapped cavity on the interior side of the poly A/V barrier (a Nunavut typical new home construction)

3) a 2X8 framing and cavity filled with semi-rigid mineral fibre insulation, with additional insulation in a strapped cavity on the interior side of the poly A/V barrier (a method adopted for CMHC E2 project in Dawson YT)

4) a structural insulated panel (SIP), with additional insulation in a strapped cavity on the interior side of the poly A/V barrier

5) an I-Joist framing and cavity filled with semi-rigid mineral fibre insulation, with additional insulation in a strapped cavity on the interior side of the poly A/V barrier 6) a double-stud wall consisting of a 2X6 framing filled with semi-rigid mineral fibre

insulation, a gap filled with mineral fibre insulation, a poly A/V barrier and a 2X4 framing with semi-rigid mineral fibre insulation

These assemblies will be tested in an NRC-IRC environmental chamber, the Environmental Exposure of Envelope Facility, for comparing their hygrothermal response when subjected to an innovative test protocol that replicate some of the extreme climate conditions defined in other tasks of the project (Tasks 3 and Task 1).

Introduction

The main objective of this project is to develop building envelope assemblies that are energy-efficient and durable under extreme indoor and outdoor climates. The focus is on the

hygrothermal performance of building envelope systems in climate extremes in the northern and humid northern-coastal areas. Activities of this project include the following:

• a review of literature on high energy-efficiency technologies (Task 2A) and a series of community consultation on typical wall construction practices (Task 2B), leading to the selection of promising wall construction methods for further investigation (Task 4)

• the characterization of extreme indoor and outdoor climates through field surveys of 24 homes (Task 1), and analysis of meteorological data (Task 3) leading to the development of test protocols applicable to laboratory experimentation on selected wall assemblies (Task 5A) • laboratory investigation of the comparative hygrothermal response of wall assemblies subjected to innovative test protocols (Task 5A); and numerical modeling of the hygrothermal response for conditions others than those investigated in laboratory studies (Task 5B)

• an investigation of the energy and environmental impact of such assemblies (Task 6) and • activities of technology transfer for the dissemination of outcomes of the project in Northern communities (Task 7).

Objective

Task 4 consisted of reviewing the work plan at mid-span of the project and selecting promising wall assemblies that will subsequently be subjected to laboratory and numerical modeling assessment.

Methodology

The project was designed so that a review of the literature on building envelope technologies related to energy efficiency1, and a community consultation on typical and innovative construction methods for the North2, along with input from project partners would yield the necessary information for making a selection of promising wall assemblies for assessment. Project partners at Canada Mortgage and Housing Corporation and Natural Resources Canada met with the NRC-IRC project team on June 12 and 13 2007 to review progress and to select test wall assemblies.

Results

Review of the work plan

The review of the work plan was conducted during the meeting on June 12th and 20th, 2007. In summary each task has been initiated, some are completed with final reports released while other tasks are either at the analysis stage or a preliminary stage of development. Each task leader presented the status of the activities accomplished to date, underway and foreseen. Findings and methodology were discussed. A one-pager describing progress on each Task was distributed. Agenda, minutes and set of one-pagers can be found in the Appendix of this report .

Selection of promising wall assemblies

Six wall assemblies were selected to be included in the laboratory studies for extreme cold and dry regions North of 60th parallel: five innovative wall assemblies and one typical 2X6 stud cavity filled with glass fiber insulation to act as a reference. Table 1 provides a description of the

composition of the specimens with the rationale for the selection of the wall assembly. Figures 1 to 6 provide horizontal and vertical section views of the wall assemblies.

Table 1 Description of Selected Test Wall Specimens

Test Frame

Test Specimen

Test Wall Specimen Rationale

W1

Typical R2000 2X6 construction

Painted wood lap siding, housewrap, OSB, R20 glass fiber batts, poly, painted gypsum

This is the reference wall, which the other specimens will be compared to.

No. 1

W2

Prefinished structural smart panel siding, housewrap, 2X6, 5.5 in. mineral fibre, poly, 2X3 strapping and 2.5 in. mineral fibre semi-rigid insulation, painted gypsum board

This is Nunavut Housing Corporation (NHC) typical new house construction detail. NHC has indicated interest in getting it evaluated. Variations on this theme of “wrap and strap” are used in Yukon and NT as well.

W3

Hardboard lap siding*, 1X3 strapping, housewrap, OSB, 2X8, 7.5 in. batt, poly, 2X4 strapping, 3.5 in. mineral fibre insulation, painted gypsum board

This is the wall composition (Wall “B”) for the CMHC E2 house in Dawson city Yukon.

*The specs for the house called for cedar siding but it was agreed that hardboard siding would be an acceptable alternative for testing, so that W3 to W6 have the same siding type.

No. 2

W4

Hardboard lap siding,

housewrap, load-bearing 6.5 in. SIP (with EPS), poly, 2X2 strapping with 1.5 in. mineral fibre semi-rigid insulation, painted gypsum board

SIP systems can provide rapid close up of the exterior skin of the walls and induce minimal thermal bridging. The strapped cavity on the interior side of the poly provides additional insulation and reduces penetration of the A/V barrier.

W5

Hardboard lap siding,

housewrap, OSB, 7.5 in. I-joist filled with mineral fiber

insulation, poly, 2X2 horizontal strapping filled with 1.5 in. mineral fibre insulation, painted gypsum board

This I-joist system permits large amount of insulation while using less quantities of dimensional lumber, and less thermal bridging. The strapped cavity on the interior side of the poly provides additional insulation and reduces penetration of the A/V barrier.

No. 3

W6

Prefinished structural smart panel siding, housewrap, 2X6 with 5.5 in. mineral fibre insulation, 2 in. gap filled with mineral fibre insulation, poly, 2X4 studs with 3.5 in. mineral fibre insulation, painted gypsum board

This double wall construction was selected for the CMHC Nunavut E2 project. It permits the installation of a large amount of insulation. Even though it is a labour intensive construction method, the outside shell can be closed off, and work can be completed inside afterwards.

WOOD SIDING

DUPONT HOMEWRAP TYVEK MEMBRANE OSB (7/16 in.)

2X6 FRAMING @ 600 mm (24 in.) o.c. / R20 GLASS FIBRE BATTS

POLYETHYLENE AIR & VAPOUR BARRIER GYPSUM BOARD (½ in.)

INTERIOR EXTERIOR

WOOD SIDING

DUPONT HOMEWRAP TYVEK MEMBRANE OSB (7/16 in.)

2X6 FRAMING @ 600 mm (24 in.) o.c. / R20 GLASS FIBRE BATTS

POLYETHYLENE AIR & VAPOUR BARRIER GYPSUM BOARD (½ in.)

INTERIOR EXTERIOR

PRE FINISHED STRUCTURAL SMART PANEL SIDING DUPONT HOMEWRAP TYVEK MEMBRANE NO OSB

2X6 FRAMING @ 600 mm (24 in.) o.c. / 5.5 in. MINERAL FIBRE POLYETHYLENE AIR & VAPOUR BARRIER

2X3 HORIZONTAL STRAPPING @ 600 mm (24 in.) o.c. / 2.5 in. MINERAL FIBRE SEMI-RIGID INSULATION GYPSUM BOARD (½ in.)

INTERIOR EXTERIOR

PRE FINISHED STRUCTURAL SMART PANEL SIDING DUPONT HOMEWRAP TYVEK MEMBRANE

NO OSB

2X6 FRAMING @ 600 mm (24 in.) o.c. / 5.5 in. MINERAL FIBRE POLYETHYLENE AIR & VAPOUR BARRIER

2X3 HORIZONTAL STRAPPING @ 600 mm (24 in.) o.c. / 2.5 in. MINERAL FIBRE SEMI-RIGID INSULATION GYPSUM BOARD (½ in.)

INTERIOR EXTERIOR

SEALANT AT JOINT BETWEEN PANELS 2x4 BACKING AT SIDING JOINT

HARDBOARD LAP SIDING (1' x 6' boards) 1X3 VERTICAL STRAPPING

DUPONT HOMEWRAP TYVEK MEMBRANE OSB (7/16 in.)

2X8 FRAMING @ 600 mm (24 in.) o.c. / 7.5 in. MINERAL FIBRE INSULATION POLYETHYLENE AIR & VAPOUR BARRIER

2X4 HORIZONTAL STRAPPING / 3.5 in. MINERAL FIBRE GYPSUM BOARD (½ in.)

INTERIOR EXTERIOR

HARDBOARD LAP SIDING (1' x 6' boards) 1X3 VERTICAL STRAPPING

DUPONT HOMEWRAP TYVEK MEMBRANE OSB (7/16 in.)

2X8 FRAMING @ 600 mm (24 in.) o.c. / 7.5 in. MINERAL FIBRE INSULATION POLYETHYLENE AIR & VAPOUR BARRIER 2X4 HORIZONTAL STRAPPING @ 24 in. / 3.5 in. MINERAL FIBRE

GYPSUM BOARD (½ in.)

INTERIOR EXTERIOR

WOOD SIDING

DUPONT HOMEWRAP TYVEK MEMBRANE LOAD-BEARING SIP (6.5 in. SIP)

POLYETHYLENE AIR & VAPOUR BARRIER 2X2 HORIZONTAL STRAPPING @ 24 in. / 1.5 in. MINERAL FIBRE SEMI-RIGID INSULATION GYPSUM BOARD

INTERIOR EXTERIOR

WOOD SIDING

DUPONT HOMEWRAP TYVEK MEMBRANE LOAD-BEARING SIP (6.5 in. SIP)

POLYETHYLENE AIR & VAPOUR BARRIER 2X2 HORIZONTAL STRAPPING @ 24 in. / 1.5 in. MINERAL FIBRE SEMI-RIGID INSULATION GYPSUM BOARD

INTERIOR EXTERIOR

WOOD SIDING

DUPONT HOMEWRAP TYVEK MEMBRANE OSB (7/16 in.)

7.5 in. I-JOIST / MINERAL FIBRE POLYETHYLENE AIR & VAPOUR BARRIER 2X2 HORIZONTAL STRAPPING @ 24 in. / 1.5 in. MINERAL FIBRE SEMI-RIGID INSULATION GYPSUM BOARD (½ in.)

INTERIOR EXTERIOR

WOOD SIDING

DUPONT HOMEWRAP TYVEK MEMBRANE OSB (7/16 in.)

7.5 in. I-JOIST / MINERAL FIBRE

POLYETHYLENE AIR & VAPOUR BARRIER 2X2 HORIZONTAL STRAPPING @ 24 in. / 1.5 in. MINERAL FIBRE SEMI-RIGID INSULATION GYPSUM BOARD (½ in.)

INTERIOR EXTERIOR

SMART PANEL SIDING

DUPONT HOMEWRAP TYVEK MEMBRANE 2X6 MINERAL FIBRE R-22 / FRAMING 24 in. O.C. 2 in. GAP WITH MINERAL FIBRE BATTS R-10 POLYETHYLENE AIR & VAPOUR BARRIER 2X4 SEMI RIGID INSULATION R-13 / FRAMING 24 in. O.C.

GYPSUM BOARD (½ in.)

INTERIOR EXTERIOR

SMART PANEL SIDING

DUPONT HOMEWRAP TYVEK MEMBRANE 2X6 MINERAL FIBRE R-22 / FRAMING 24 in. O.C. 2 in. GAP WITH MINERAL FIBRE BATTS R-10 POLYETHYLENE AIR & VAPOUR BARRIER 2X4 SEMI RIGID INSULATION R-13 / FRAMING 24 in. O.C.

GYPSUM BOARD (½ in.)

INTERIOR EXTERIOR

610 mm [24 in]

*

*

Instrumented Stud Cavity

*

2400 mm. [96 in]

2400 mm. [96 in]

Airtight and high R-value separator between specimens

ELEVATION VIEW

W1

W2

TOP VIEW

W1

W2

Figure 7 Test frame setup, with two test specimens side-by-side separated by a guard to minimize lateral heat and mass flow

Conclusion

Now that the set of promising wall assemblies has been selected, the project will move to the next stage of characterization of their hygrothermal performance (Task 5) as well as their energy and environmental impact assessment (Task 6).

References

1. Said, M.N., PERD 079 B1239 Report on Task 2: Literature Review- Building Envelope, Heating, and Ventilating Practices and Technologies for Extreme Climate, Institute for Research in Construction, National Research Council Canada,. 2006, 108 p.

2 Cornick, S.M. and Rousseau M,. PERD079 B1239 Interim Report Task 2B - Community Consultation on Wall Construction Methods, Institute for Research in Construction, National Research Council Canada 2007, 25 p. (also available in French).

Appendix

NRC-IRC PERD 079 Progress Meeting

June 12th, 2007 8:30-12:00

Building M-20 2

Floor Executive Conf. Room

NRC-IRC 1200 Montreal Road Ottawa

Agenda

8h30

Welcome, objectives, agenda (Coffee and tea will be available)

Review of Project Tasks:

Task 1

Field surveys of indoor conditions

Task 2

Literature review

Task 2B Community consultation

Task 3

Climate characterization

Task 4

Work plan review and selection of wall assemblies

Task 5A Laboratory testing

Task 5B Hygrothermal computation analysis

Task 6A Energy impact analysis

Task 6B Environmental impact analysis

Task 7A Final report

Task 7B Seminar Tour

11h00

CMHC project-related activities

11h20

NRCan project-related activities

11h40

Action items

Task 1 Field Surveys of indoor Conditions - Progress Report

Objective

To characterize the indoor conditions of RH and T in several houses in northern and northern climates, as well as the basic characteristics of the bldg envelope, the occupants and the mechanical services and moisture problems

Progress

− 3 field surveys of indoor temperature and relative humidity in 8 houses each are completed and reports received

o Prince Rupert BC (April-May 2005) o Inuvik NT (Nov-Dec 2005)

o Carmacks Yukon (Jan-Feb 2006) − IRC report of analysis being prepared

Findings

− Survey in First Nations Community (Carmacks Yukon) showed poor quality of construction (very leaky), large range of indoor temperatures (central wood stove heating in 7 of the 8 homes), mould problems present in “moisture troubled” and “non-moisture troubled” houses − Survey in Carmacks Yukon showed average RH readings between 17-49%RH and average

temperature readings between 15 and 28ºC for the month of monitoring.

− Survey in Inuvik NT showed low average RH readings (between 10-30%) and temperature readings indoors on the warmer side (between 20-26ºC) for the month of monitoring. The houses were older and leaky. Frost formed on interior surfaces. Moisture damage of interior surfaces resulting from melting frost was a common problem.

− Survey in Prince Rupert BC showed average RH readings between 36-65%RH and average temperature readings between 19 and 25ºC for the month of monitoring.

− Surveys did not show a direct link between occupancy loads, moisture problems and higher relative humidity indoors. Quality of construction (i.e., airtightness, level of insulation, glazing type) and ventilation has an impact as well. Most of these houses were very leaky, had levels of insulation typically found in southern construction (R20) and traditional double glazed windows. Most houses had manually operated exhaust fans in bathroom and/or kitchen.

− Peaks of RH levels near saturation were measured in bathrooms and kitchen in all three surveys.

Deliverables

One NRC report along with the 3 consultant reports.

Outcome

The data is used for the development of a test protocol the wall test specimens will be subjected to in NRC-IRC Environmental Exposure of Envelope Facility

Outreach

− Article in NRC-IRC Construction Innovation Newsletter published (March 2007)

− PowerPoint talks on Inuvik and Carmacks surveys were presented in Northern Communities (in Feb 07 – see Task 2B), and are posted on NRC-IRC PERD 079 project website

(http://irc.nrc-cnrc.gc.ca/bes/hmpe/north60pubs_e.html)

− Paper submitted at the Thermal Performance of the Exterior Envelopes of Whole Buildings X International Conference in Florida Dec. 2007

Future activities

Task 2B Community Consultation - Progress Report

Objective

To engage the building community in the development & evaluation of innovative high performance wall construction methods suitable for northern communities needs & constraints

Progress

− 3 community consultation sessions were conducted in Feb. 2007 in Yellowknife NT, Arviat NU and Whitehorse Yukon.

− Participants included public housing corporations, builders, municipalities, Public Works and Government Service Department, architects, engineers, energy consulting firms,

manufacturers, NRC-IRAP, tenant association representatives, First Nations building managers, Yukon Cold Climate Innovation Centre rep.

− An interim report of the consultation notes was reviewed by the communities and circulated to Partners (June 2007)

Findings

− “Keep It Simple” approach must prevail.

− Transportation costs are a driver in material selection (e.g. board stock insulation is much more expensive and less practical to transport without damage than batt and semi-rigid insulation.)

− The building shell needs to be closed in quickly. Wall systems with few outside layers are preferred (exterior insulation sheathing are not commonly used for this reason)

− Panelized systems are not much favored, even though in theory these could allow for quick shell close-in time and reduced labour intensity. Concerns over the need for hard-to-achieve-on-site tight tolerances, detailing of joints, damage during transportation and the need for creating jobs and developing local construction skills make these less attractive.

− For reasons mentioned above, double stud wall technology is not favoured. − Use of open cell SPF was reported having potential for interfaces of components

− Several innovative construction methods have been tried over the years up North but little information appears to be available on their performance.

− Risks of creating double vapour barrier with foam plastics on the exterior are a concern limiting their use in new construction (in NT and Yukon. Use in retrofit apparently led to some cases of moisture entrapment and premature deterioration.

− Interest in combining SIPs (and using these for their structural capability) with traditional stick framing was mentioned in NU.

Deliverable

One NRC report summarizing the consultation notes.

Outcome

The data is used for the selection of the type of wall assemblies for evaluation with experimental and modeling studies

Outreach

− The report will be sent to all communities consulted and posted on NRC-IRC website.

Future activities

− Support to the Yukon Cold Climate Innovation Centre (Whitehorse Yukon) in setting up a Northern Information Portal where this and other types of information would be made available to northern communities, as the need for such sharing platform was expressed in some places and the suggestion met approvals in other places.

Task 3 Climate Characterization -Progress Report

The climate characterization task serves as a basis for the development of the chamber test protocols (Task 5B), the selection of appropriate survey locations (Task 1), the selection of locations for hygrothermal simulations (Task 5A) and energy analysis (Task 6A). The scope of the task was limited to low-rise residential construction, exterior environmental conditions, energy and hygrothermal performance of walls. Interior conditions addressed partially in Task 1

Status:

• Complete

Plan:

• n/a

Summary:

The recommended criteria selecting extremely cold Canadian climates are:

1. Locations where the mean number of days where daily minimum is less than -20oC is 100 or more, and/or

2. Locations where the annual of heating degree-days above 18oC is 8000 or more.

The recommended criteria selecting extreme coastal Canadian climates are:

1. Extreme wet and humid climates as defined in this study shall be locations where the MI value calculated as per the NBCC 2005 exceeds the theoretical limit of √2 i.e. 1.414 or,

2. Where the mean annual rainfall exceeds 1250 mm.

A lower limit of 1000 residents was set to ensure an adequate building stock for the survey portion of this project. It was felt that for coastal regions there would be a sufficient number of locations large enough to provide an adequate stock of residential buildings. Based on the criteria set out above, as well as the availability of suitable weather data, five locations are recommended for further examination in this project. The five locations are:

1. Inuvik, Northwest Territories – Extreme cold 2. Yellowknife, Northwest Territories – Extreme cold 3. Iqaluit, Nunavut – Extreme cold

4. Prince Rupert, British Columbia – Extreme wet and humid

5. Halifax (Shearwater), Nova Scotia – Extreme wet and humid (if an eastern location is desired)

Outputs

• Client report: Report on Task 3: Extreme Canadian Climates – Northern and Coastal, Report No: B-1239.3, July 2005.

Task 4 Review Work Plan and Select Wall Assemblies - Progress Report

Objective

To review work plan and select wall assemblies for laboratory and modeling studies

Progress

− Feeding Tasks 2A and 2B are completed

− Information on the CMHC E2 project in Dawson city Yukon received.

Proposal of wall assemblies for experimental studies Number and configuration of test specimens

− Three 2400 mm by 2400 mm test frames with 2 test specimens each will be subjected to a test protocol aiming to challenge these with extreme outdoors and indoors conditions. Two test specimens will be mounted side-by-side into a test frame. An airtight and highly insulated “guard” will isolate the test specimens from each other, minimized mass and heat transfer between these.

• 6 wall tests specimens will be tested for cold climate

• 2 additional test specimens will be tested for northern coastal climate.

− The test specimen will be opaque (i.e. no windows). Deficiencies in the specimens (e.g cracks providing an air leakage path) will be introduced at a given stage of testing, to challenge the wall specimens and compare their hygrothermal response in a before/after conditions.

Composition of the test specimens for cold climates

Test Wall specimen Rationale

No.1 Structural wood siding, housewrap, 2X6, R22 mineral fibre, poly, 2X2 strapping and R7 mineral fibre semi-rigid insulation, drywall

This is Nunavut NHC typical new house construction detail. NHC has indicated interest in getting it evaluated. Variations on this theme of “wrap and strap” are used in Yukon and NT as well. This would be our reference.

No.2 Cedar siding, 1X3 strapping, housewrap, OSB, 2X8, R28 batt, poly, R4.5 EPS, 2X3 strapping, R9 mineral fibre, drywall

This is the wall composition (Wall “B”) for the CMHC E2 house in Dawson city Yukon.

No.3 Wood siding, housewrap, 2X3 and semi-rigid mineral fiber R12, OSB, 2X6 with R22 mineral fiber, poly, drywall

This is a system with exterior insulation sheathing. This system could have benefits for minimizing thermal bridges at wall/floor connection (cold floors near periphery were reported in Nunavut), and maintain the wood structure and the OSB above dew point for longer periods (compared to interior insulation strategies. The approach has been used somewhat in Alaska in the “Remote” system. Drawback : labour intensive for exterior close-in of shell.

No.4 Wood-based siding, housewrap, load-bearing SIP (6 in. EPS), 2X2 strapping R7 mineral fibre semi-rigid insulation, poly, drywall

This is a system using SIP panels combined to interior insulation. SIP systems can provide rapid close up of the exterior skin of the walls and have minimal thermal bridging. Quality of joints to control movement and maintain airtightness is critical.

No.5 Wood siding, housewrap, OSB, vertical I-joist filled with insulation, poly, drywall

This is a I-joist wall system. This system permits large amount of insulation to be placed with less

Test Wall specimen Rationale

No.6 Wood siding, housewrap, OSB, cavity with staggered steel stud (or wood studs), filled with low-density SPF, poly, drywall

Or

Wood siding, housewrap, OSB, 2X4 stud cavity filled with SPF, 2X3 strapping filled with SPF, poly, drywall

This test specimen would take advantage of the air barrier property and insulation value of open cell sprayed polyurethane foam system.

In the consultations, many participants expressed an interest for open cell low-density polyurethane foam applications. As well in Nunavut it was reported that transportation costs for steel studs are lower than those for wood studs. Steel studs are currently being used for partitions in some Nunavut houses. Staggered steel studs and SPF could minimize thermal bridging and provide an airtightness plane, and would not impact on the closing in of the outer shell. Control of thermal bridging due to high thermal conductivity of the steel stud requires careful detailing.

Deliverable

A report will describe the proposed test specimens and the rationale for their selection.

Outcome

The selected wall systems will be subjected to testing and modeling in Task 5, and to energy and environmental impact evaluation in Task 6.

Outreach

− The report will be sent to the communities consulted (Task 2B) for feedback.

Future activities

Task 5 Hygrothermal Assessment of Proposed Wall Assemblies

Objective

− To evaluate the hygrothermal performance of proposed building envelope assemblies in Task 4 using the Environmental Exposure Envelope Facility (EEEF)

− To conduct a parametric study to assess the hygrothermal performance of the selected building envelope assemblies is Task 4 using the state-of-the-art hygrothermal tool hygIRC.

Progress

− Test protocol for interior is in progress. Two protocols to be developed, the Northern protocol and the Coastal protocol.

o First draft of exterior protocol for Northern wall testing completed June 2006 o Coastal exterior protocol not started.

− Test protocol for exterior in progress. Two protocols to be developed, the Northern protocol and the Coastal protocol.

o First draft of exterior protocol for Northern wall testing completed June 2006 o Coastal exterior protocol not started.

Proposal of wall assemblies for the experimental studies (See Task 4) Experiment

Number and configuration of test specimens

− Three 2400 mm by 2400 mm test frame with 2 test specimens each will be subjected to a test protocol aiming to challenge these with extreme outdoors and indoors conditions. Two test

specimens will be mounted side-by-side into a test frame. An airtight and highly insulated “guard” will isolate the test specimens from each other, minimized mass and heat transfer between these. • 6 wall tests specimens will be tested for cold climate

• 2 additional test specimens will be tested for northern and coastal climate

− The test specimen will be opaque (i.e. no windows). Deficiencies in the specimens (e.g. cracks providing an air leakage path) will be introduced at a given stage of testing to challenge the wall specimens and compare their hygrothermal response in a before/after conditions.

• The assessment will concentrate on performance parameters for heating and high humidity climates of the northern and humid northern-coastal regions.

Modeling

Computations will be coordinated with the laboratory testing studies in order to obtain data to benchmark computation as well as provide data for the design of the laboratory testing.

Deliverable

A report describing the experimental study performed in EEEF with the selected wall assemblies (Results and Analysis) and the parametric study using the state-of-the-art hygrothermal tool hygIRC.

Future activities

Task 5A Wall Testing – Exterior Protocol

The exterior protocol determines the conditions on the weather side of the Envelope Environmental Exposure Facility (EEEF), Task 5B. Two protocols to be developed, the

Northern protocol and the Coastal protocol. The scope of the protocol includes temperature and RH, wind, p, solar radiation, and wind-driven rain for the coastal protocol.

Status:

• In progress

• First draft of exterior protocol for Northern wall testing completed June 2006 • Subsequent minor revisions

• Circulated during Northern community consultations, Feb 2006 • Little to no comment received so far on Northern protocol • Coastal exterior protocol not started

Plan:

• Revise Northern protocol possibly including solar radiation and diurnal cycling • Finalize Northern protocol – Target date: - Sep 2007

• Draft Coastal protocol prepared by Jan 2008.

Summary:

Northern wall protocol to date

Cold Side Temperature and RH Profiles

-50 -45 -40 -35 -30 -25 -20 -15 -10 -5 0 5 10 0 168 336 504 672 840 1008

Time from Steady State, h

Cold side T, °C 50 55 60 65 70 75 80 85 90 95 100 Cold Side RH, % T, C RH, % Winter conditions Summer c onditions Sp ri n g con diti ons

The suggested temperature and relative humidity profiles for the exterior side of the EEEF based on the above analysis is given here, divided into 24-hour intervals.1

HTC and ΔP Profiles 20 25 30 35 40 45 50 55 60 0 168 336 504 672 840 1008

Time from Steady State, h

HT C, W/m-° K ; Δ P, Pa HTC, W/m-*K DP, Pa Winter conditions S ummer con diti ons Spring conditions

The suggested pressure difference across the wall from inside to outside and suggested heat transfer coefficient to be maintained on the cold side of the EEEF based on the above analysis is given here, divided into 24-hour intervals.

Coastal wall protocol to date

Coastal regions protocol to be developed. Build on protocols developed previously.

• Cornick, S.M.; Lacasse, M.A. "A Review of climate loads relevant to assessing the watertightness performance of walls, windows and wall-window interfaces," Journal of ASTM International, 2, (10), Nov/Dec., pp. 1-16, November 01, 2005 • Cornick and M. A. Lacasse “An Investigation of Climate Loads on Building

Facades for selected locations in the US” Journal of ASTM International, Nov/Dec., pp. 1-16, November 01, 2007

MEWS protocol

Outputs2:

• Client report: Exterior Testing Protocol: Extreme Northern (Oct 2007) • Client report: Exterior Testing Protocol: Extreme Coastal (Feb 2008)

•

2

Task 5A Wall testing – Interior Protocol

The interior protocol determines the conditions on the interior (room) side of the Envelope Environmental Exposure Facility (EEEF). Two protocols to be developed, the

Northern protocol and the Coastal protocol. The scope of the protocol includes temperature and RH.

Status:

• In progress

• First draft of interior protocol for Northern wall testing completed June 2006 • Subsequent revisions

• Circulated during Northern community consultations, Feb 2006 • Little to no comment received so far on Northern protocol • Coastal interior protocol not started

Plan:

• Revise Northern protocol • Finalize Northern protocol • Target date: Sep 2007

• Draft coastal protocol prepared by Jan 2008.

Summary:

• Results Task 1 survey will be used to create interior boundary conditions. • Temperature is proposed to be held constant at 25°C

• Three potential methods for setting the boundary relative humidity conditions on the room side:

o A. Constant conditions: The indoor chamber is set at a constant temperature humidity condition. Pros: Constant conditions can be easily achieved and controlled. Cons: No evaluation of dynamic swings in interior conditions – as recorded during the survey. o B. Dynamic offset from the exterior conditions: A dynamic offset

from the exterior conditions. Pros: Dynamic loads similar to those seen throughout the surveys. Cons: Control of moisture would be complex; like option A short-term moisture loads are not addressed. o C. Interior T and RH profile: A daily T and RH profile based on the

survey results is produced incorporation humidity peaks and temperature set backs. Pros: Typical 24hr profile simulates peaks and troughs typical of occupant behaviour; other profiles exist for comparison. Cons: More difficult to control than prolonged constant conditions; does not follow ambient conditions4.

• All options have their advantages and disadvantages that need to be further explored before determining a final test protocol.

• 50% 70% 90% 3 gv/kgda 50% 90% 90% 90% Interior Conditions Exterior Conditions

A – Constant Condition B – Dynamic Offset from

Exterior Conditions

C – Dynamic Interior Condition with Peak Humidity Events

Options for Setting Experimental Interior Boundary Conditions Outputs5:

• Client report: Interior Testing Protocol: Extreme Northern (Oct 2007) • Client report: Interior Testing Protocol: Extreme Coastal (Feb 2008) • Conference Paper: Testing Protocols for Northern Homes: Part 2 Interior 6

5

Task 6A Energy Analysis – Progress Report (as of June 12 07)

The objective the energy analysis task is to assess the impact of the wall designs selected on the whole house performance using the hygrothermal performance characteristics derived from the Task 5 – Wall Testing. The scope is limited to single family, single zone, single system homes, a single year IWEC type calculation. Only wall will be compared in the study, cooling will not be considered.

Status:

• Not started

Plan:

• Selected one or more energy analysis packages; (EnergyPlus, ESPr, HOT3000 for e.g.)

• Construct basic houses to modeled; 1) single family detached; 2) typical row-house (5-plex for the Northern regions, row-row-house for Coastal regions e.g.) • Select typical Northern and Coastal locations for modeling.

• Conduct comparative modeling for Northern and Coastal areas. • Report on Northern study.

• Report on Coastal study.

Schedule:

• Select modeling tool(s) – Aug 2007

• Construct Northern house models – Sep 2007 • Select Northern locations – Sep 2007. • Construct Coastal house models – Dec 2007 • Select Coastal locations – Dec 2007.

• Preliminary modeling studies based on selected Northern walls – Dec 2007. • Remainder of the schedule is dependant on Task 5 Wall Testing.

Summary:

• n/a

Outputs7

• Client report: Energy Impact Analysis: Extreme Northern (Mar 2008) • Client report: Energy Impact Analysis Extreme Coastal (Mar 2008)