摘要 |
A ventilation system comprises a window unit with a rectangular window frame having a hollow interior constituting a flow passage for air, and a ventilator held in fluid communication with the hollow interior of the window frame. The ventilator has a built-in heat exchanging element which effects a heat exchange between fresh air and foul air during operation. The window frame has an integral pipeline disposed in the hollow interior of the window frame at the interior side of the window unit for the passage therethrough of a heat-transferring medium. The heat-transferring medium flowing through the pipeline gives up heat to, or extracts heat from the air channeled through the flow passage in the window frame prior to or after the air's being introduced into the ventilator. Thus, the efficiency of heat exchange is considerably increased. |