Ads
related to: inline duct fans cfm counter pressure meter
Search results
Results from the WOW.Com Content Network
Duct leakage test in the US. A duct leakage tester is a diagnostic tool designed to measure the airtightness of forced air heating, ventilating and air-conditioning (HVAC) ductwork. A duct leakage tester consists of a calibrated fan for measuring an air flow rate and a pressure sensing device to measure the pressure created by the fan flow.
Actual cubic feet per minute (ACFM) is a unit of volumetric flow. It is commonly used by manufacturers of blowers and compressors. [1] This is the actual gas delivery with reference to inlet conditions, whereas cubic foot per minute (CFM) is an unqualified term and should only be used in general and never accepted as a specific definition without explanation.
An air flow meter is a device similar to an anemometer that measures air flow, i.e. how much air is flowing through a tube. It does not measure the volume of the air passing through the tube, it measures the mass of air flowing through the device per unit time, though Thus air flow meters are simply an application of mass flow meters for the ...
The Dall tube is a shortened version of a Venturi meter, with a lower pressure drop than an orifice plate. As with these flowmeters the flow rate in a Dall tube is determined by measuring the pressure drop caused by restriction in the conduit. The pressure differential is typically measured using diaphragm pressure transducers with digital readout.
This pressure difference forces air through all holes and penetrations in the building enclosure. The tighter the building (e.g. fewer holes), the less air is needed from the blower door fan to create a change in building pressure. Typically, only depressurization testing is performed, but both depressurization and pressurization are preferable.
Figure 1: Components of a centrifugal fan An external motor belt driven inline centrifugal fan discharging inline to the exterior of a building through a duct. Unlike non-inline/non-concentric impeller casing design with a cutoff blade above, the concentrically symetric cylinder casing and impeller geometry of inline type redirects the outflow around so that it is parallel to the inflow of gases.
Ads
related to: inline duct fans cfm counter pressure meter