Energy Efficiency Testing

Do you feel drafts in your home?

Do pesky critters keep finding their way in?

We offer certified blower door testing, which can help with a whole lot more than testing ACH on a new build.

We test all our builds. Our latest project was our tightest house yet, with a 1.065 ACH50. A heating recovery ventilator (HRV) was installed to constantly pump fresh, filtered air into the house.

What is a blower door?

A blower door is a calibrated testing instrument used to either pressurize or depressurize a building and measure the amount of airflow at a given pressure (usually in pascals), commonly referred to as "ACH." The structure is tested at 50 pascals and referred to as ACH50.


What is "ACH?"

ACH is "air changes per hour." ACH is a universal measurement and requirement for a building to meet state or local requirements. For example, did you know Montana follows the 2018 Internation Energy Conservation Code, which requires less than 4 ACH50? That's four air changes per hour at 50 pascals, which is equivalent to a roughly 20 mile per hour wind blowing at the side of a structure.


AHHH! You're building the house too tight! Houses need to breathe!

These are typical comments, and the science that accompanies this technology has been around for a long time. The first thing to understand is that we're not trying to stop all air movement. The goal is to manage the air. HRV and ERV systems are employed to exchange air from inside and outside through air filters and a heat exchanger. Homes don't need to breathe, but the people inside do! These units supply fresh, clean filtered air, as well as tempering the air that enters the house.






Testing to find where the draft or the mice keep coming in?

Yes, that's correct. Most people blame the windows for the draft, and they are often the culprit. Other times, the window install itself is guilty of the drafty conditions. This doesn't always mean poor workmanship. More often, the cause is material shrinkage and failed sealants. How? The wood the window flange is fastened to may have shrunk over time, leaving a small gap around the perimeter of the window. We use a synthetic smoke/ fog machine similar to what is seen in concert venues, and depending on the project, we will pressurize or depressurize the structure and use a fog machine to find the holes.

How low can you go? More information can be found at the links below.