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Testing-Failed a Code Required Blower Door Test, Now What?

2012 was the first year the International Energy Conservation Code required residential construction to pass an air leakage rate test, better known as a blower door test.  My area of the country requires the test to be at or below 3 air changes per hour at the test pressure of 50 pascals (ACH50).  (Other areas, typically warmer climates require 5 ACH50.)  Most new construction in my market has no problem passing the test, but I have had a handful of houses fail, usually the failed tests are by a builder having their first blower door test or the project is a very small home.

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Testing-Setting up a Home for a Blower Door Test

This post was originally published in the April 2022 issue of the Journal of Light Construction.  www.jlconline.com

Blower door testing a home requires much more than simply setting up the equipment and running the test.

When setting up a house for a blower door test, should you seal off the bath fans? How do you address that six-inch combustion air vent in the mechanical room?  Should the overhead garage door in the attached garage be open or closed? Continue reading “Testing-Setting up a Home for a Blower Door Test”

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Shorts-Attached Structures Outside the Air Control Layer and Blower Door Testing

Whether you are performing blower door testing or hiring someone to perform the test for you, it’s a good idea to understand how a home should be setup for the test.  Should a door be open or closed?  What can be sealed off?  How to address rooms attached to the house but are outside the air control layer?  That’s today’s topic, attached garages and three season porches.  How should those spaces be setup for a blower door test?

Continue reading “Shorts-Attached Structures Outside the Air Control Layer and Blower Door Testing”

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Building Science-Ice Dams

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”

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Building Science-Existing Construction Improvements

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”

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Building Science-Three Way Buildings Leak Air

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”

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Energy Audit-Calculating the Cost of a Home’s Air Leaks

Air leaking into a home (infiltration) or out of a home (exfiltration) happens naturally in every home, new or old.  No matter how much air sealing is performed, we just can’t make them completely air tight.  I’ve tested some new homes that were very tight, .33 ACH50, (anything under 1 ACH50 is very good) and I’ve also tested many older ones that aren’t so tight, we can use my 1952 Cape as an example, 9.71 ACH50.  In this post, I’m going to discuss how to manually calculate the cost of the air leakage and examine what we can do with that number. Continue reading “Energy Audit-Calculating the Cost of a Home’s Air Leaks”

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Building Science-An Interview with Gary Nelson

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”

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Energy Audit-Measuring for Blower Door Testing

Whether you are using equipment from Minneapolis Blower Door, Retrotec, or any other blower door manufacturer, one of the first steps in conducting a blower door test is to measure the home’s floor area, volume, and surface area.  Coming up with the floor area is the simplest, length times width.  Calculating volume also isn’t hard, width times length time height, simple right?  Not always, getting the volume of a geodome or a complex cathedral ceiling often takes some time. Continue reading “Energy Audit-Measuring for Blower Door Testing”