1:20 pm - 2:30 pm | Room: Taylor Hall | Session Chair: Leslie Peer

Building Material Performance

Vacuum-Insulated Wood-Framed Walls - How Do They Measure Up?

High performance housing standards in Canada require high levels of insulation. Homebuilders have traditionally employed thick wall assemblies that are often twice as deep as conventional walls to achieve the necessary thermal resistance [RSI 6.0-8.8  (R 28-50)].  Because they cannot protrude beyond zoning setbacks, these thick walls can negatively affect livable area. This has a real cost to buyers (> $25,000 per home in some markets,) on top of additional materials and labour. This has been identified as a barrier to adoption of such housing. 

In collaboration with an industry partner, CanmetENERGY and Carleton University developed and evaluated a polystyrene/vacuum insulation panel system for insulating and air-sealing thin, high R-value wood-framed walls. The research team constructed prototype assemblies, measured the effective R-value under steady-state conditions in a guarded hot box, and installed in the CanmetENERGY Building Envelope Test Hut (CE-BETH) for in-situ field exposure and long-term monitoring over a four-year period.  

The thermal resistance of the test assemblies was determined to be between RSI 7.6 to 9.0 (R-43 to R-51), twice that of today’s code-built homes. Durability criteria were established based on the ASHRAE 160 standard to calculate the of mould index and air conditions at the surface of sensitive materials. Temperature, humidity, and moisture content of the wall sheathing was measured over a 4-year period. These measurements were used to assess the risk of mould growth on the structural sheathing and framing members.  

During the 4-year monitoring period the durability criteria were satisfied; however, these assemblies were observed to be at higher risk of mold growth compared to a baseline assembly. The mould index  peaked at 2.4 during the summer of 2017. The dry out period with the initial moisture content was longer than expected and the sheathing experienced wetting from the interior due to high interior humidity conditions. For long-term durability and resilience, this wall system requires excellent bulk water management and mechanical control of indoor humidity. It was observed that this design is best suited for off-site construction to prevent damage to its fragile VIPs.

 

speaker pic

Brock Conley, Natural Resources Canada

 

bio coming soon.

 

 


Thank You to Our Current Sponsors

  • Diamond Sponsor

    edge group
  • Emerald Sponsor

    artistic skylight domes
  • Emerald Sponsor

    owens corning
  • Emerald Sponsor

    pretium
  • Emerald Sponsor

    pretium
  • Emerald Sponsor

    soprema
  • Gold Sponsor

    exp
  • Associate Sponsor

    cufca
  • Silver Sponsor

    elastochem
  • Silver Sponsor

    elastochem
  • Silver Sponsor

    pcl construction
  • Silver Sponsor

    prodemnity
  • Bronze Sponsor

    Ellis Don
  • Bronze Sponsor

    Entuitive
  • Bronze Sponsor

    HRI
  • Bronze Sponsor

    HRI
  • Bronze Sponsor

    Leading Edge
  • Bronze Sponsor

    NaturaSeal
  • Bronze Sponsor

    NaturaSeal
  • Bronze Sponsor

    rdh
  • Bronze Sponsor

    State Window Corporation
  • Bronze Sponsor

    Synergy Partners
  • Bronze Sponsor

    tremco
  • Bronze Sponsor

    tritan
  • Bronze Sponsor

    Sealtight