Abstract
The application of exterior insulation in both new construction and retrofits is a common practice to enhance the energy efficiency of buildings. In addition to increased thermal performance, the rigid insulation can serve to keep the sheathing board warm and serve as a water-resistive barrier to keep moisture-related problems due to condensation and wind-driven rain. Polyisocyanurate (PIR) rigid boards have a higher thermal resistance in comparison to other commonly used exterior insulation boards. However, because of its perceived lower permeance, its use as exterior insulation is not very common. In this study, the hygrothermal property of PIR boards with different facer types and thicknesses is characterized. The material data obtained through experimental test and extrapolation is used in a long term hygrothermal performance assessment of a wood frame wall with PIR boards as exterior insulation. Results show that PIR with no facer has the smallest accumulated moisture on the sheathing board in comparison to other insulation boards. Walls with a bigger thickness of exterior insulation perform better when no vapor barrier is used. The PIR exterior insulation supports the moisture control strategy well in colder climates in perfect wall scenarios, where there is no air leakage and moisture intrusion. In cases where there is trapped moisture, the sheathing board has a higher moisture content with PIR boards with both aluminum or fiberglass type facers. An innovative facer material development for PIR boards can help efforts targeting improved energy-efficient and durable wall systems.
| Original language | English |
|---|---|
| Article number | 3373 |
| Pages (from-to) | 1-15 |
| Number of pages | 15 |
| Journal | Materials |
| Volume | 13 |
| Issue number | 15 |
| DOIs | |
| State | Published - Aug 2020 |
Funding
Funding: This manuscript has been partially authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the US Department of Energy. The authors would like to acknowledge the funding provided by NSERC Engage grants and the school of Construction and Environment at British Columbia Institute of Technology. Keywords: drying and wetting; hygrothermal performance; Polyisocyanurate board; moisture content; thermal performance; vapor permeability This manuscript has been authored in part by UT-Battelle, LLC, under contract DE-AC05–00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).
| Funders | Funder number |
|---|---|
| US Department of Energy | |
| U.S. Department of Energy | |
| Natural Sciences and Engineering Research Council of Canada |
Keywords
- Drying and wetting
- Hygrothermal performance
- Moisture content
- Polyisocyanurate board
- Thermal performance
- Vapor permeability
