Musings of an Energy Nerd

The crowds at the GreenBuild conference in Toronto are daunting; according to USGBCUnited States Green Building Council (USGBC). Organization devoted to promoting and certifying green buildings. USGBC created the LEED rating systems., there are 23,000 attendees this year. As an indefatigable journalist, however, I've managed to survive the crush to board the escalators and have patiently waited my turn in the long lines that form to use the rest room.

If you're interested in new products, check out my photos from the trade-show floor.

If you want to get a flavor of some of the information provided in the presentations, I've culled a few memorable quotes for you to enjoy.

The GreenBuild conference in Toronto, Ontario, opened its gates on October 5, 2011. This is the first time that the U.S. Green Building Council has held its annual conference outside of the United States.

What’s the best way to install foam insulation on the outside of a wall?

Although GBAGreenBuildingAdvisor.com has published many articles and videos on the topic, we continue to receive frequent questions from readers asking how to install rigid foam sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. on exterior walls.

My conclusion: it’s time to provide a primer on the topic.

Homes insulated with fiberglass batts are leakier than homes insulated with cellulose or spray polyurethane foam. Until recently, fiberglass batt manufacturers shrugged off the damning air-leakage data, insisting that their batts could deliver the R-valueMeasure of resistance to heat flow; the higher the R-value, the lower the heat loss. The inverse of U-factor. promised on the packaging — and then changed the subject.

UPDATED and CORRECTED on 9/22/2011

Are you ready for the 2012 code? Each revision of the International codes tends to ratchet up energy performance requirements, and the 2012 revision is no exception.

Although its adoption may be a long ways off in some jurisdictions — after all, many rural areas of the U.S. still have no building codes at all — the 2012 International codes may become law in some areas as soon as next year.

About every six months, I report on new products that catch my eye. This round-up features products from both sides of the Atlantic Ocean: high-performance windows from Maine, Ontario, and Lithuania; high-performance doors from Poland; and high-performance tapes from Switzerland.

Should spray polyurethane foam be installed in an occupied house? Hundreds of spray foam contractors around the country are happy to answer “Yes!” In almost all cases, these jobs end successfully: the spray foam improves the home’s thermal performance and the homeowner is happy.

A subset of green builders have always been grumpy about foam. Such builders look at rigid foam panels and spray foam as suspect products: they are made from petroleum, laced with mysterious chemicals, and impermeable to vapor flow.

R-valueMeasure of resistance to heat flow; the higher the R-value, the lower the heat loss. The inverse of U-factor. is the poor stepchild of building science metrics. Although it is often essential for builders, designers, and engineers to know a material’s R-value, this useful metric is regularly abused, derided, and ridiculed for its shortcomings. “R-value doesn’t measure assembly effects: thermal bridges, air movement, thermal massHeavy, high-heat-capacity material that can absorb and store a significant amount of heat; used in passive solar heating to keep the house warm at night. , moisture content — all of which can all affect thermal properties,” explained Chris Schumacher, an engineer and researcher at Building Science Corporation, at a summer symposium in 2009. “R-value doesn’t do a good job describing the entire system.”

Older buildings with load-bearing brick walls are common in many northern U.S. cities. While these thick (muti-wythe) brick walls were often plastered on the interior, they were rarely insulated.