Blower Door and Duct Testing Equipment are designed to identify air leakage in a home, building, or facility. Air leakage in a home, building, or facility can increase heating and cooling costs dramatically and cause problems with comfort, moisture, and health. While the technology has been around for many years , it is still not yet commonplace, so there is great opportunity for contractors who want to add this service to their capabilities. Retrotec Inc. is the world's leading manufacturer of air leakage testing equipment.
How much can be saved by making upgrades following testing?
According to Energy.gov 5-30%
Who should purchase Blower Door and Duct Testing Equipment?
- Home Inspectors
- Professional Energy Auditors
- HVAC/R Contractors
- Large Facility/Property Managers
How does a Blower Door System Work?
An apparatus consisting of a calibrated variable speed fan built into an assembly is installed in place of a door. Manometer gauges or digital manometers are also installed to measure pressure differential. Outside air is forced into the property being evaluated creating a positive pressure as compared to outside or the reverse is performed creating a negative pressure. The auditor can use a smoke pencil to locate air leaks.
Data typically collected from Blower Door tests:
- Air flow at various pressures
- Air-changes per hour (ACH)
- Leakage area (ELA)
- Air flow per area
Why test ducts?
Leaky ducts pose health, safety, and comfort problems and account for about 25% of the total energy lost in a typical house. The United States Environmental Protection Agency (EPA) states how Duct Leakage Testing is “
by far the most cost effective way to save energy”, as building codes now demand higher performance. Although visual duct inspections may be allowed in some states, duct testing provides an easier, faster, verifiable pass /fail test result.
Duct systems can be significant contributors to air leakage in any building. In many cases, these leaks can be the hardest to find and fix. Even small leaks in duct systems can be a major problem, if air is pulled in from polluted or contaminated areas such as carports or damp, moldy crawlspaces.
A typical Duct Leakage Testing System is comprised of four main parts:
- A flex duct to connect to the ducts and provide a hole to mount a fan.
- A calibrated fan, capable of creating a measurable flow of air.
- A two-channel differential pressure gauge that can also calculate flow for a particular fan.
- A fan speed controller to change the air flow through the fan (can be provided by the gauge).
The specially designed calibrated fan is temporarily connected to the ductwork system using the flex duct. The fan is used to blow air into or out of the ducts to measure the air leakage of the enclosure. The gauge measures the pressure across the calibrated fan and calculates the flow or other values of interest (such as flow per area or equivalent leakage area).
Air leakage is the infiltration or exfiltration of air from the ductwork. In order for leakage to occur, there must be a hole, and there must be a pressure difference across the hole.
Retrotec DucTester Systems measure the amount of air leakage by establishing a pressure difference between the inside and the outside of the ductwork. The pressure difference forces air to leak through all of the holes in the ducts. The amount of air flow that is required to maintain a constant pressure difference is equal to the amount of air that is leaking from the ducts. A specially designed gauge can thus be used to measure the pressure difference and calculate the amount of air flowing through the calibrated fan, which can then be used to determine the total size of all those leaks.