Changeover arrangement for a central air conditioning unit

摘要

A valve is provided with one inlet (106) and two outlets (104, 108) with one (109) of the outlets being normally closed by a valve in the form of a film disc (130) carried by a flexible blade (122). A magnetic pad (128) secured to the blade (122) is attracted by the proximity of an actuator carrier magnetic element (165) to cause the flexing of the blade (122) to open the normally closed outlet (104) and to close the normally open outlet. The actuator (164) may be either thermally or electrically actuated and is suitable to override a bleed thermostat to permit warm-up of an overcooled area or to cause a switch-over in operation between heating and cooling mode.