A Cold Climate Construction and Energy Blog
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 is 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”
As I write this post at the end of November, our outdoor temperature is 28°F with an outdoor humidity of 75%. Inside my home, the temperature is 70°F with a humidity level of 21%. Slightly uncomfortable humidity levels for my family. During last year’s polar vortex, when the temperatures reached nearly -40°F, my indoor humidity dropped to 9%, much too dry. Knowing what I know about building science, I will not operate a humidifier. This post will explain why. Continue reading “Building Science-Wintertime Interior Humidity”
*This post first appeared on the Green Building Advisor website.
In the typical year, I’m in about 100 homes conducting energy audits and assessments, many of the homes are older. The work I do is to help a customer form a plan to deal with their high energy costs in operating the home, in my area, that is usually heating related. The first thing most homeowners will look to do is add insulation or air seal the building. Those steps will improve the cost to operate the home, but the changes may have a detrimental effect in other areas. Before we form a plan to air seal and insulated, there are other considerations that must be addressed. Continue reading “Building Science-Address Moisture Before Energy Improvements”
I have talked many times about blower door testing, air sealing and air leaks in this blog, on the Green Building Advisor’s website, and more recently, in the pages of Fine Homebuilding Magazine. Most of what I’ve written deals with testing a home or techniques used in air sealing a home. This time I’m going to discuss the mechanisms that cause air to leak, there are only three of them, but first a little science. Continue reading “Building Science-Three Way Buildings Leak Air”
I’m a big fan of exterior insulation. It’s rarely used in my area, mostly because the State of Minnesota has eliminated that code requirement. It has to to with our wide use of polyethylene sheeting as a vapor retarder on the warm in winter side of a wall assembly and then adding a low permeance plastic insulation product as exterior insulation. These plastic foams would be the choice for most contractors, lower cost and easy to source. Very slow vapor movement in either direction when a wall assembly becomes wet. This posting isn’t going to get into the foam insulations, but more into what exterior insulation can do for a home. Continue reading “Building Science-A Benefit of Exterior Insulation”
I think most of us know of this man, one of the founders of The Energy Conservatory and designers of the Minneapolis Blower Door. I recently had the opportunity to chat with Gary. My intent with the interview is a little different from other interviews that have featured Mr. Nelson. I wanted to ask questions from a practitioner working in the field point of view. Continue reading “Building Science-An Interview with Gary Nelson”
If you’re a nerd like me, chances are you’ve heard of WUFI. WUFI is a German acronym that basically translates to heat and moisture movements through a building assembly. This is called hygrothermal analysis, it predicts wetting and drying of an assembly and lets us know if that assembly is risky. Continue reading “Building Science-WUFI”
Recently I was at a house conducting an energy audit when the homeowner indicated they were experiencing high humidity in the master bathroom. The windows were fogging up and they had some mold growing in one of the ceiling corners. They operate a bath fan regularly but it didn’t seem to remove any moisture. Continue reading “Building Science-How to Test a Bath Fan.”
I recently tested the Code Minimum House for air tightness at the rough framing stage. We ended up where I was hoping at this first test, .55 ACH50, 140 CFM. Given the volume of the home, the leakage area is equal to approximately 15 square inches. Continue reading “Building Science-A Visual for Blower Door Testing”
Wait…What? Building science and a custom shower? Yep! As some of you may know from my Instagram feed, I can’t stay busy doing energy audit, assessments and building diagnostics or residential energy design in my area. Continue reading “Building Science-Custom Shower”