| 摘要 |
<p>Recuperative heat exchangers are disposed in the supply and exhaust ducts of a ventilating system. To reduce frost build-up at the exit end of the exhaust-duct heat exchanger, the heat exchanger is disposed so that the exhaust air flows through it alternately from one end to the other, and vice-versa, when the temperature is below freezing. The reversal of flow of the exhaust air is accompanied by a reversal of the flow of heat exchange medium so that the efficiency of heat exchange is not adversely affected. Several systems of heat exchange are disclosed.</p> |
