Airtightness testing with a Blower Door

A blower door can be used to check how airtight a structure is. It is designed to detect air leaks in walls, attics, and mechanical penetrations. While a blower door test does not evaluate how well a structure is insulated, it can reveal drafty walls and air-bypass situations that undermine otherwise well insulated wall assemblies.

We perform blower door tests with all the energy assessments as well as mid-construction blower door tests, that is done during New Homes Construction and with Step Code Compliance Reporting.

The results of a blower door test are used in our CSA F280-12 Heat Load Calculation. This improve the accuracy of the calculation as it is based on test results and not assumptions (used in some F280 calculation procedures).

The results of a blower door test will be presented in a number of ways:

ACH50

Let us start with ACH50,it stands for Air Changes per Hour at 50 Pascals. This is the number of times per hour that your space heating system will need to reheat the air volume in your house during a winter storm with winds of about 35 miles per hour.

However, understanding ACH50 is crucial for homeowners, builders, and anyone aiming to lower energy costs and improve indoor air quality.

A “good” ACH50 value depends on the building type and location:

New Homes: For most new homes in British Columbia, an ACH50 value of 2.5 or lower meets current energy codes. Some energy-efficient homes aim for a value as low as 1.0 or even 0.6, particularly for Passive House certifications.
Existing Homes: Older homes often have higher values, sometimes reaching 5.0 or more. Retrofitting and sealing air leaks can greatly improve these numbers.

ELA10

The Heating Ventilation and Air Conditioning Industry use Effective Leakage Area (ELA) and equivalent leakage area (EqLA).
In layman’s terms, this is the equivalent size hole in your house when all the small air leaks are added.

EfLA is usually based on an induced building pressure of 4 Pa. Back before the days of the 50 Pa target pressure for testing homes, 4 Pa was used to measure the hole size in American homes building envelope under natural conditions.

However, we in Canada use ELA10, this is the test performed at 10 Pa depressurization and this result will be included in your Home Renovation Upgrade Report.

Retrotec 5000 BLOWER DOOR

Thermographic Scan with a Blower Door

In addition to the standard blower door test, we also do an Infrared thermal scan with the blower door running. Thermal videography is used to locate and identify air leaks and poorly insulated areas in the building. This is a powerful method that will help the advisor and building owners to develop a strategy to improve building envelope tightness, proper ventilation, reduce energy usage and increase occupant comfort and health.

FLIR camera used for thermographic scan