A vent hood or fitting that creates excessive back pressure not only lengthens the drying cycle but accelerates dangerous lint build-up. Higher energy bills and increased risk of fire become the obvious outcome. Until now, there was no assessment of the back pressure that these popular vent hood designs and fittings provide. The below chart provides the actual difference or delta (∆) of air pressure measured with a Magnehelic Gauge* before and after the fitting was attached (Differential Pressure). The higher the value, the less efficient the fitting is. These days, being energy efficient is important step in the direction of drying smart. Consider these values when shopping for a dryer vent fitting or hood.
Airflow Efficient Ratings Matrix by Product
*Magnehelic Gauge: A sensitive differential pressure or vacuum gauge manufactured by Dwyer Instrument Co. that uses a precision diaphragm to measure pressure differences. This gauge is manufactured in specific pressure or vacuum ranges such as 0 to 2 inches of water column. Airflow was provided by a typical residential clothes dryer.