Blower Door Testing For Commercial Building Enclosures

The Blower Door Test is an important part of the commissioning procedure for residential, multifamily, and commercial projects. This air-leakage testing measures the flow of conditioned conditioned air through the building enclosure with a standardized differential pressure.

The data reveals a range of air tightness metrics. These metrics can vary depending on which standard and method was used. These metrics can be used for estimating HVAC design infiltration.

Construction Standards Are Changing

The blower door test can be a very effective way to discover leaky areas. A large fan is mounted in your exterior entranceway. The fan lowers the pressure of the interior air to reveal any cracks, crevices, or openings through which air can enter or leave the building.

The technicians can gather useful data to determine heating and air conditioning equipment size requirements. Blower-door data is usually compiled and expressed in air changes per hours at a specified pressure of the building, like 50 pascals.

These metrics are determined by measuring indoor and outdoor air pressures and the airflow of the fan using digital gauges attached to the blower door hardware. As temperature and barometric force affect air viscosity and density, they must be compensated for to get accurate measurements.

Energy Efficiency

Blower-door testing can be used to detect air leakage in construction or renovation. Airtight buildings will improve comfort and reduce energy costs.

Basic test: A calibrated blower is sealed temporarily into a doorway or window opening, and then used to pressurize building enclosure. The fan's pressure imbalance forces air into the building enclosure through any cracks or holes. Airflow through fan is measured, and then compared to the building pressure. This gives a known series of values for Qfan.

The test could include a stack-effect pressure as a baseline to account for temperature differences between the interior of the building and the exterior. The airtightness in the building can then be compared against a performance standard or a third party specification. Depending on standard and project, the results can either be used to demonstrate code conformity or to pinpoint areas in need of remediation.

Indoor Air Quality

Blower door testing helps identify air leaks and their impact on comfort. Accurate Airtight Exteriors utilizes this data, along with a visual examination and infrared-technology to help resolve problems of our client's commercial, industrial or multiple family buildings.

This test measures the enclosure of a structure by using high-powered fans to either depressurize or pressurize it. By creating a difference in pressure between inside the building and outside, air is forced through all openings and penetrations. Depending on which standard is being used, different metrics will be used.

They include the number and rate of air changes at a specific indoor/outdoor air pressure differential as well the amount of exterior air required to equalize pressure in the interior. This is done to account for temperature differences. It's important because temperature changes can affect pressure.

Comfort

Blower door tests are essential during construction for many different reasons. It accurately identifies leakage of air, leading to an improved insulation as well as reduced heating and cool costs. It increases indoor comfort as it ensures consistent temperature control. This allows a builder, who is in compliance with ACH50 for their specific climate zone, to qualify for certain energy incentive programs.

The blower system is made up of a metal expandable frame that can be fitted into any window, exterior door or opening. There's also a nylon panel mounted to the frame. And a calibrated air fan to move the air. It is attached to a monoometer or pressure gauge as well as a laptop computer which tracks metrics like ACH50.

To ensure a positive test result, prepare the house or space by closing and locking all interior door during the test. It is important to turn off all exhaust fans and gas-burning devices, since they can introduce carbon monoxide in the test environment.