초록 ▼

A variable air volume ventilation system (10) is disclosed in which the output air flow from a supply fan (13), delivered through a supply duct (11) to various places within a building, is returned by a return duct (15) through a return fan (17) and then through a connecting duct (18) back to the in

A variable air volume ventilation system (10) is disclosed in which the output air flow from a supply fan (13), delivered through a supply duct (11) to various places within a building, is returned by a return duct (15) through a return fan (17) and then through a connecting duct (18) back to the inlet (20) of the supply fan (13). The static pressure in the supply duct (11) is sensed by a static pressure sensor (40), and the output signal indicative of pressure is used by a variable frequency power supply (44) to provide power to drive the fan motors (36, 37) at a frequency inversely proportional to the difference between the sensed static pressure and a desired static pressure, thereby adjusting the flow through the ventilation system to match demand. Outside make-up air is provided through an outside air duct (50) and is fed into the return duct (15) at a position (52) near the inlet (16) of the return fan (17). The air flow through the outside air duct is controlled to a constant flow rate which matches the expected rate of exhaust air from the building so that the flow of air into and out of the building is balanced despite changes in the rate of flow through the ventilating system in response to demand.

대표청구항 ▼

A ventilation system for a building comprising: (a) a supply duct; (b) a return duct; (c) a supply fan, having an inlet and an outlet connected to the supply duct, which is driven by an AC electric motor; (d) a return fan, having an inlet and an outlet connected to the return duct, which is driven b

A ventilation system for a building comprising: (a) a supply duct; (b) a return duct; (c) a supply fan, having an inlet and an outlet connected to the supply duct, which is driven by an AC electric motor; (d) a return fan, having an inlet and an outlet connected to the return duct, which is driven by an AC electric motor; (e) a connecting duct extending from the outlet of the return fan to the inlet of the supply fan; (f) means responsive to a condition indicative of the ventilation demands of the building for providing electrical power to the motors driving the supply and return fans at a frequency varying in response to the condition sensed in the building to change the speed of the fans in a manner which tends to restore the condition to a pre-selected value; (g) an outside air duct extending from an intake communicating with the atmosphere outside the building to connection to the return duct at a position ahead of the inlet of the return fan; (h) a flow sensor positioned in the outside air duct to sense the air velocity therein and provide an output signal indicative thereof; (i) damper means in the outside air duct responsive to a control signal for controlling the resistence to flow therethrough and thereby controlling the velocity of air flow in the outside air duct; (j) outside air duct control means, receiving the output signal from the flow sensor and connected to provide a control signal to the damper means, for controlling the damper means in response to the rate of flow in the outside air duct to maintain a substantially constant flow velocity in the duct, whereby the flow rate through the outside air duct may be set to match the expected flow rate of air exhausted from the building being ventilated.