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Moving air handlers from attics is a good idea…even better add more attic insulation at the same time…what could go wrong?The worst thing you could do is install furnaces and air conditioning systems… Read More

For a bunch of supposedly clever folks we sure do dumb things. One of the big ideas of the past couple of decades or so is to keep the heat out during cooling and keep the heat in during heating. The… Read More

Here is a pop quiz for you folks that are bored of Jeopardy. California is desert. Florida is a swamp. We build concrete slab-on-grade in both places. Which place has more slab moisture problems? Yes… Read More

Buildings today are hollow and multilayered with numerous air gaps or void spaces. Chases, shafts, soffits and drops abound. Everything is connected to everything else, typically unintentionally.… Read More

The perfect wall is an environmental separator—it has to keep the outside out and the inside in.  In order to do this the wall assembly has to control rain, air, vapor and heat. In the old days we… Read More

The energy used in institutional, commercial, and industrial buildings in cold climates (zone 4 and above) is substantial. Most of this energy is used after construction is complete; hence, reducing… Read More

Condensation within walls during cold weather is a common performance problem. Most such condensation is due to air leakage, not diffusion. Although air barrier and vapor control layers can reduce… Read More

Putting metrics on building energy performance is a required step to make any progress on low-energy use and/or “green” buildings. However, there are many confusing and contradictory metrics… Read More

The difference between site and source energy is a vital concept to understand when looking at the energy performance of buildings—failing to account for the difference will result in an apples-to-… Read More

Unvented roof assemblies, such as conditioned attics and unvented cathedral ceilings, are becoming common in North American construction.  These assemblies are created by eliminating ventilation… Read More