Three Key Concepts When Insulating High-Performance Buildings

I was recently asked to write an article as a digital supplement for Construction Canada magazine, with the general topic requested being thermal/moisture protection for municipal, university, school, and hospital facilities (MUSH). I decided to focus on the thermal control layer, and titled the article “Three Key Concepts When Insulating High-Performance Buildings” (click on the article title for a direct link to the article). It was published online in March 2020 by Kenilworth Media Inc. I hope you enjoy it! – David Organ

“When designing building enclosures, several complex and integrated considerations are required. These include, in part, the water, air, vapour, and thermal control layers. While all are equally critical to the integrity of the building, the scope of . . . [the] article focuses on key considerations when specifying the thermal control layer at opaque walls for Canadian municipal, university, school, and hospital (MUSH) high-performance buildings.” – David Organ

To supplement the published article I thought I would add the following information:

Two popular simulation software offerings include THERM Finite Element Simulator and the WUFI® family of software products. Other offerings include EE4, eQUEST, DOE 2, EnergyPlus, IES Virtual Environment, Hourly Analysis Program (HAP), TRACE 700, and EnergyPro.

Thermal Break Products: There are various thermal break products and systems available to the designer in Canada that serve to interrupt thermal conductivity pathways, some of which are available from but not limited to the following manufacturers: Armatherm™ Thermal Bridging Solutions, Schoeck Canada Inc., Fabreeka International, Inc., JK Thermal, Peikko Canada, Tnemec Company, Cascadia Windows & Doors, Knight Wall Systems, and Engineered Assemblies. Also noteworthy are the following: fibreglass pressure plates for curtain walls have been available for many years; OmniGlass SCT manufacturers a fibreglass curtain wall system; Cascadia Windows & Doors, in addition to its fibreglass clip, offers a fibreglass curtain wall vent adaptor that offers a fibreglass sash and frame in place of aluminum; and GlasCurtain Inc. manufacturers fibreglass curtain wall systems, their newest system, ThermPH+, is certified to Passive House Institute (PHI) Cold Climate criteria (0.6 W/m2K – R9.5).

“The function of a water-resistive barrier is to keep liquid water from entering the building enclosure. Combined with flashing and other materials, the water-resistive barrier ensures that there is a shingled assembly to direct liquid water to the exterior”, and also, “A single material can function as all three, an air, vapour and water-resistive barrier. There are also materials that function only as a water-resistive barrier that are not air barriers. Understanding the functions of the materials used is critical so that the building performs in accordance with the Project requirements” – Carlisle Coatings & Waterproofing.

Dew Point is “[t]he temperature at which the water vapour contained in a volume of air at a given atmospheric pressure reaches saturation and condenses to form dew. The dew point varies depending on how much water vapour the air contains, with humid air having a higher dew point than dry air. If the dew point temperature is reached within . . . [a wall assembly], condensation occurs, wetting the walls resulting in insulation ineffectiveness and deterioration of moisture-sensitive materials” – Carlisle Coatings & Waterproofing.