This post originally appeared on the Green Building Advisor Website.
A couple years ago I was asked to perform a blower door test on a new home. The home was small with a footprint of only 1130 square feet. When the test was completed, the test report indicated an air leakage rate of 91 CFM at the test pressure of 50 Pascals, .33 ACH50. Completely unexpected for this code-built house. (I actually measured the volume of the home again and ran the test two more times before I was convinced I had an accurate test.) The contractor contacted me some time later and indicated the homeowners were noticing air coming through the exterior light switches when the dryer was operating. The dryer was producing close to the same negative pressure as my blower door every time it was being used, a negative pressure of about 50 Pascals. Is this a problem?
Continue reading “Building Science-Tight Homes and Negative Pressures, When Should We Be Worried?”
This year seems to be a good (or bad depending on how you look at it) year for ice dam problems in my area, the intensity of ice dams seems to change year to year. I was recently on an ice dam diagnostic with an insulating contractor and a general contractor, the home was built in the early 1990’s and there is evidence there have been issues from the beginning. We spent a couple hours testing this home, I’ll get into what we found in a bit.
Continue reading “Building Science-Ice Dams”
This three-part series first appeared on the Green Building Advisor website and has been condensed into one post.
An unconditioned and uninsulated crawlspace, an unsealed and uninsulated forced air heating system, and an uncovered dirt floor, which by the way has a sewage leak. If this were your home and you wanted to make improvements, where would you start? Continue reading “Building Science-Existing Construction Improvements”
I’ve been asked this question a few times. “At what point do I need to add mechanical ventilation to my home?” The answer, it depends. Continue reading “Energy Audit-Ventilation Recommendations”
My last posting I talked about air changes at 50 Pascals (ACH50) and air changes natural (ACHnat). This week I’m going to discuss how much fresh air a home needs in a northern climate and a couple of the codes Minnesota has in force that work well. One of these codes, the requirement for balanced ventilation, helps add durability to our structures. Continue reading “Building Science-Air Changes”
I watched an electrician install two ceiling fans in an attached garage recently while I was working as a subcontractor on a new home being built. I quizzed him on their use and he said moisture control. This got me thinking about controlling humidity in a heated garage in a northern climate, this week’s topic. Continue reading “Construction Design-Humidity Control in a Garage”
Bath fans serve a few different functions. Removing moisture, removing odors, and if noisy enough, to drown out sounds. Continue reading “Mechanicals-Bathroom Ventilation”
One of the questions I always ask while conducting an energy audit or assessment is if there is a build-up of frost or water vapor on any of the windows during the heating season. Usually, the answer is no. But I do occasionally get a yes, what is this piece of information telling me? Continue reading “The Energy Audit-My Moisture on Window Question”
I’ve had several discussions on this blog about the importance of a tight home, “built it tight and ventilate it right”. Continue reading “Mechanicals-Heat Recovery Ventilators”