Tag: Building Science

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Code-Blower Door Testing a Small Home

This post originally appeared on the Green Building Advisor website.

Code compliant blower door testing of a small home can be very frustrating for both the person performing the test and the homeowner or contractor who are required to have the test.  A few months ago, I tested a 952 square foot, newly constructed home with a volume of 7616 cubic feet, one of the smallest I’ve tested.  The house had a leakage rate of 416 cfm which resulted in a 3.28 ACH50 number.  A failed blower door test (my climate requires 3 ACH50 or less).  If we take that same CFM rate but increase the ceiling height to 9 feet, which changes the volume to 8568 cubic feet, 2.91 ACH50, a passing test.  Either way, 416 CFM of air moving through the blower door isn’t much, some kitchen exhaust hoods can move more air than that.  Seems unfair to punish smaller homes when blower door testing, especially when the blower door test is testing the surface of a structure, not it’s volume.

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Windows-Water and Air Sealing

I’m going to make a statement that not everyone will agree with, windows leak water.  Not all are leaking now, some will develop the leak later, as the window and the sealing products used to install the window age.  The leak may be an error or failure in the installation, or it could be the window itself that is leaking.  It could be a design error, water funneling off a roof over a window, such as in the photo.  The leak may only be an incidental amount of water, or it could be a major bulk water concern.  The leak may also only be active during the once every ten-year major rain fall event.  The point is windows will leak water.

Photo by Eric Strommer-Strommer Home Improvements

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The Thermal Bridge

Thermal imaging is an awesome tool, it can be used to find areas of missing insulation and other temperature anomalies in the building shell.  It can help us find issues with electrical, plumbing and heating systems.  And when used in conjunction with a blower door, we can often “see” the air leaks.  The photo below was taken without the assistance of a blower door, I was at this new home to conduct a blower door, but the test hadn’t begun at the time this photo was taken, can you say thermal bridge!

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What is R-Value?

This is the first in a series of blogs I’ve written for Rockwool and the R-Class Builder Program.  If you are not already a member, you can join at this link, Rockwool R-Class.  The R-Class program is free.

What is R-value?  I write often about different insulations, how they perform, where they should and shouldn’t be used.  I think this blog post should go back to the basics and talk about what is R-value, how it is calculated, and how much is needed.

This concrete foundation is not insulated, concrete has a much lower resistance to heat flow (R-Value) than the insulated wall. This becomes evident when using thermal imaging. Heat is leaving this structure through the concrete. Insulation will slow this heat loss.

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Indoor Air Quality and Building Diagnostics

The post originally appeared on the Green Building Advisor website.

I recently purchased the CPS IAQ PRO SmartAir professional indoor air quality meter to use during energy audits and building diagnostics/investigations.  My intent with the purchase was two-fold, first to learn more about indoor air quality metrics by testing homes in my market, and second, to have a more accurate temperature/humidity/dew point estimation inside these homes.  I recently had the opportunity to use the tool on a building investigation, I’ll outline this case study later in this post.  First let’s talk about the features of the CPS IAQ PRO SmartAir.

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Why You Need Blower Door Testing

This article first appeared in issue 304 of Fine Homebuilding Magazine.

I bought my first blower door in 2009, back when new construction was in a downturn and energy auditing and weatherization projects were on the rise.  I took a 40-hour energy auditing training course at a local college which included hands-on training on how to use a blower door.  It took many tests before I became comfortable in its operation and understood the information it was providing.  Though one of the more expensive tools I own, I’ve been able to keep it busy and add this specialized testing to my business’s income stream.

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Construction Education-Texas Building Science Symposium

This post originally appeared on the Green Building Advisor website.

I recently made the 1349-mile trip from my home in Northern Minnesota to Austin, Texas.  Stepping off the plane in Austin at 9:30 in the evening on November 8th, my first impression was it was hot, hot and muggy.  Much different than the 35°F when I left Minnesota.  I was taking my first trip to Texas to attend the Texas Building Science Symposium.  A two-day event of nothing but building science education.

Ben Bogie, Steven Baczek, Enrico Bonilauri, Allison Bailes, Jake Bruton and Peter Yost. (Not pictured, Glenn Mathhewson.)

The Texas Building Science Symposium is an off shoot of the Midwest Building Science Symposium started by the Kansas City chapter BS and Beer group.  Travis Brungardt and Joe Cook started the symposium in 2020, which I had the pleasure of attending.  That first event had two speakers, Steven Baczek and Jake Bruton.  In 2021, the event grew to include more speakers.  This year, the symposium was held not only in Kansas City, but also in Chattanooga, Tennessee, Austin, Texas, and an upcoming event in Washington, DC. Continue reading “Construction Education-Texas Building Science Symposium”

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Building Science-Tight Homes and Negative Pressures, When Should We Be Worried?

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?

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Building Diagnostics-Single Point vs Multi-point Blower Door Testing

This Article first appeared in the September/October issue of The Journal of Light Construction.

The main purpose of a blower door test is to confirm the integrity and continuity of the air control layer or air barrier.  I have a few different options on how to perform a test.  Which option I choose is dependent on the reason I am performing the test.

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Construction Education-Construction Instruction

This post originally appeared on the Green Building Advisor’s website.  https://www.greenbuildingadvisor.com/

I recently took a trip to Denver, Colorado for a couple days of construction education, specifically a two-day class on high performance HVAC and IAQ.  The course was offered by Ci, or Construction Instruction and combined classroom learning with real-world, hands-on education in their adjacent testing center.

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