ADAPTIVE MAKEUP AIR SYSTEM AND METHOD FOR TIGHT ENCLOSURES

摘要

A system and method for introducing external air into an enclosure having an exhaust fan for removing internal air at an outflow rate. A sensor measures a quantifiable characteristic which is indicative of the outflow rate. Based on the measured quantifiable characteristic, a controller determines a speed of a makeup air fan that results in the inflow rate matching the outflow rate, and opens a damper and runs the makeup air fan at the determined speed. For example, the sensor may measure an amount of electrical current flowing to the exhaust fan, and low and high speed exhaust fan values are stored in a memory, and corresponding low and high makeup air fan speeds are set. The controller then controls operation of the makeup air fan based on the amount of current flowing to the exhaust fan and the corresponding makeup air fan speed to match the inflow and outflow rates.

主权项

1. A makeup air system for introducing external air into an enclosure, the enclosure having an exhaust fan for removing internal air from the enclosure at an outflow rate, the makeup air system comprising:
a damper configured to open and close an air passage operable to direct the external air to enter the enclosure; a makeup air fan positioned in the air passage and configured to move the external air into the enclosure at an inflow rate; a sensor configured to measure a quantifiable characteristic which is indicative of the outflow rate, and to communicate a signal representative of the quantifiable characteristic; and a controller configured to receive the signal from the sensor, determine a speed of the makeup air fan based on the quantifiable characteristic that results in the inflow rate at least approximately matching the outflow rate, and open the damper and run the makeup air fan at the determined speed such that the inflow rate of external air into the enclosure at least approximately matches the outflow rate of internal air out of the enclosure.