Building Science-Perm

Builders in northern Minnesota have been using polyethylene sheeting on the warm in winter side of wall assemblies for years.  Beginning in the 1960’s, we were taught that the poly would stop vapor diffusion in building cavity, keeping walls dryer.  During the 1990’s and 2000’s, building scientists determined that only a small percentage of wall wetness comes from vapor diffusion.  So, how does moisture end up inside building assemblies in a northern climate?  Mostly by air leaks! Continue reading “Building Science-Perm”

The Energy Audit-Air Conditioners

Summer has arrived, bringing warm temperatures and higher humidity.  As a kid, I remember hot nights sleeping in the upper story of an old farm house, often also suffering from sunburn.  Now, I can’t imagine not having at least one cool room in the house for relief.  What a wimp I’ve become.  Many homes in Minnesota have some sort of air conditioning today.  This blog posting is going to discuss the different types, efficiencies, and operating costs of common air conditioners along with the basics of how they operate.
Continue reading “The Energy Audit-Air Conditioners”