| 摘要 |
<p>The control for air-conditioning systems, such as vapour exhaust hood, is in the form of a flap, deflector, throttle valve, shutter or slide and alters the relative cross-section of the exhaust air outlet and fresh air supply. The ratio between the discharged and fresh air depends on the volume and/or speed of a blower, i.e. the speed of its motor. The control may be manually or electrically operated and operates in conjunction with measurements of the system parameters, such as temperature, air pressure, humidity, fumes, odour etc. It incorporates a T- or Y-shaped pipe.</p> |
