On Fri, 2005-09-23 at 00:19 +0100, M.Blackmore wrote: > On Mon, 2005-09-19 at 12:04 -0400, [EMAIL PROTECTED] wrote: > > I had a brand new furnace installed > > this summer and don't know how prevalent the DC motor is. > Ditto. I'd never even thought to ask! In the UK, since February or March 1st (can't remember which) by law all new central heating boilers have to be condensing.
This sounds like a good thing except for the intrusion of reality: a). load factoring on a condenser is relatively critical - they have to be on the edge to work properly. How many Joe Plumbers are going to be able to get precise radiator and heat loss calculations to size or throttle a boiler so precisely?? b). Someone at a uni here (Loughborough?) did a lifecycle environmental cost of conventional high efficiency boilers and condensers. Condensers go wrong so often that any benefit of the extra 5-10% efficiency is wiped out by the fuel use of all the gas fitters running around the countryside repairing them - or as if often the case nowadays, simply ripping the entire installation off the wall and replacing them with new boilers every couple of years, given the costs of parts and the difficulty of getting components in and out of the construction. There are times when even old environmentalists despair... less efficient but durable and repairable machinery might have the long term edge in a lot of circumstances, guess I. The old Morris Minor car being a classic example of road transport in terms of its overall impact (for a motor car!)... Malcolm _______________________________________________ Futurework mailing list [email protected] http://fes.uwaterloo.ca/mailman/listinfo/futurework
