Using a flow hood. Using a blower door and pressure pan (for diagnostic purposes only) Using a blower door only (not recommended) The basic idea behind using a duct leakage tester to test for duct leakage is: Use a calibrated fan to pressurize the duct system. Measure the airflow through the fan with the duct system at pressure. In new construction, the best time to conduct a blower-door test is after the house has been insulated but before the drywall is up. At this time, leaks will be easier to find and fix. When testing older houses, a blower door can help a contractor find and seal air leaks. That process is called “blower-door-directed air-sealing.”. Duct Testing Process: Testing the ducts requires sealing all the openings of a duct system. This includes all supply and return registers. We do this by using large HVAC tape to cover and seal the openings. This process can take some time as we try to create the best seal possible. Our fan is then sealed to the air handler or a large return The blower door test takes the guess work out of detecting air leaks in a structure; however, most contractors would like to pass the blower door test the first time. It is estimated that 50% of newly constructed homes will fail the blower door or air-tightness test. The test is also most effective when conducted throughout the entire building. Blower door test results aid builders and owners in the decision-making process. It helps determine: How much effort should be spent on sealing air leaks in comparison to windows or insulation. How much mechanical ventilation is needed to create good indoor air quality. . The intense pressure from the blower door exaggerates the natural conditions to make air leaks appear more obvious. The cfm50 measurement refers to how much air is rushing back into the building as the blower door is forcing air out, depressurizing the house. A good number here would be about 800 cfm50 or 900 cfm50 for a 2000-sq.-ft. house. Using smoke pencils while depressurizing the house or fogging devices while pressurizing with a blower door can be used to help you figure out where the major air leaks are. If you have a sufficient temperature difference between the inside and outdoors you can also use infrared thermographic cameras to find the trouble areas. The air tightness test determines the amount of air leakage in cubic metres per square metre of internal surface area of the building m3. Or, to put it simply, air tightness testing measures the amount of air that escapes through the gaps or building fabrics. Ideally, having an airtight building means that less energy will be wasted through the How does a blower door work? The fan motor and blades push air out of the building with the fan sensor located where the air is being pulled into the fan [more on this below]. Channel A reads the house pressure [with the reference outside], while Channel B measures the pressure at the fan sensor and just upstream of the sensor, converting this Blower door test are really just for inspections when you have to pass certain requirements. I work in construction and build low income housing. We are strictly regulated and we have to meet certain requirements. We do blower door test to check those. On renovation jobs we have to show a certain amount of improvement.

how does a blower door test work