Blower Door Testing forms a critical part of commissioning for new construction, restoration or retrofit projects in residential, commercial and multifamily buildings. This air-leakage measurement measures the flow rate of conditioned indoor air in the building enclosure under standardized pressure differentials. The data obtained can reveal various air tightness metrics that vary depending on standard and procedure. These metrics include the number of air changes per minute at a given pressure difference. They can also be used to estimate HVAC system infiltration rates. Construction Standards are Changing In addition to complying with the building code, a blower-door test is a good way to identify leaks. Installing a large fan at your entrance will lower the internal air pressure, allowing you to see any crevices and cracks in the wall. It allows technicians to collect valuable data on the infiltration rate, which they can use to determine the heating and cooling requirements. Blower data is often compiled and presented in terms air changes per minute at a certain building pressure. For example, 50 pascals. These metrics can be calculated by measuring the indoor and outdoor pressures using the digital gauges that are on the hardware for the blower doors. Since temperature and barometric conditions affect air density, and viscosity must be taken into account, in order to accurately measure air flow. Energy Efficiency Blower door testing is a way to find air leaks during construction and renovation. An airtight building envelope reduces energy costs and increases comfort. The basic test uses a calibrated, sealed fan to pressurize an enclosure. The imbalance in pressure created by the fan forces the air through holes and cracks on the building envelope. To determine the known values of Qfan, and PnBuilding, airflow through a fan is measured. This test could also include a baseline pile effect pressure, which accounts for the difference between interior and exterior temperatures. The airtightness can then be compared with a third-party performance specification or a standard. The results can be used for code compliance, or to identify problem areas that need to be remedied. Indoor Air Quality Blower-door testing can reveal the rate of natural air infiltration and help pinpoint air leaks causing comfort issues. Accurate Airtight Exteriors combines this data with an infrared inspection and visual inspection to assist our clients in resolving problems for their commercial or industrial buildings. This test determines how tightly sealed a building is. It uses a powerful fan to create a pressure difference between inside and out, forcing air through any holes or penetrations. The metrics used depend on the standards to which a building is being tested. This includes the number of air-changes per hour at an indoor/outdoor difference in pressure and the amount outside air required to equalize the pressure inside. It is important to measure the stack-effect pressure as a baseline, which takes into account temperature differences within the building. This is crucial, as a change in temperature will cause a change in the pressure. Comfort The blower-door test is essential for many reasons during construction. It accurately identifies any air leakage leading to increased insulation and decreased heating and cooling expenses. This device also ensures a constant temperature, which increases comfort indoors. Finally, it allows a building contractor to meet certain incentive programs for energy efficiency by complying with ACH50 standard for their specific climate zones. The blower door system is composed of a metal frame which expands to fit tightly into an opening such as a window or large exterior doors. It also includes a nylon panel that is attached to this frame, and a fan calibrated to force air in or out. It is connected with a monometer, pressure gauge, and a computer laptop that tracks metrics like ACH50. To get a good result from the test, you should prepare your home or area by locking all the interior doors. The exhaust fans should be shut off and all gas-burning appliances turned off. They can create carbon monoxide backdrafts into the testing environment.