Posted by Bruce Larsen on February 11, 2000 at 08:33:08:
The more I think about it, the less I want to use electricity in my radiant floor / DHW project. At first I thought designing so if the electricity goes out, all zones valves would open to flow - now I am wondering if there is some type of non-electric (thermocoupled) valve, maybe something I can install in each room (zone) to open and close the zone valve as the floor or air temp dictates. Ideally, it would be adjustable.
Since the supply (hot) water would be flowing by convection, the pressure to open and close against would be negligible. (If more "ummphff" is needed, possibly even a tank of water in the attic could provide the working pressure to operate via hydrostatic head?). Yeah - NON-electric. Sometimes here in North Dakota, at -50 f the electricity gets thick, will hardly run through the wires.
Ideas??? Thanx - Bruce