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- Path: sparky!uunet!cs.utexas.edu!rutgers!ub!dsinc!cs.widener.edu!eff!world!moroney
- From: moroney@world.std.com (Michael Moroney)
- Newsgroups: sci.energy
- Subject: Re: hot water
- Message-ID: <BzqvCI.KL2@world.std.com>
- Date: 24 Dec 92 03:36:17 GMT
- References: <5016.1017.uupcb@spacebbs.com>
- Organization: The World Public Access UNIX, Brookline, MA
- Lines: 33
-
- howard.smith@spacebbs.com (Howard Smith) writes:
-
- >The problem with oil and gas water heaters is the flue. It has to have
- >low thermal resistance to the water and also low resistance to the flow
- >of the fumes and air up from the bottom of the flue. Much heat goes up
- >the flue.
-
- Yes, but my boiler is still supposedly 87% efficient despite no fancy flue
- gizmos. The flue is the reason it is not 100% efficient though, certain
- unvented gas and kerosene room space heaters are 100% efficient.
-
- Anyway, for the original poster, check the (required) energy efficiency
- labels on water heaters at places that sell them, this will tell you the
- efficiency better than us in this group.
-
- >Real inefficiency occurs when the heater reaches temperature and shuts
- >off, leaving the heat from the pilot light and the water, back through
- >the low thermal resistance, to pass up the flue by convection. The
- >less hot water you use, the less efficient the system. Some sort of
- >electric pilot light and automatic, insulated damper in the flue are
- >needed to stop this loss.
-
- Yes. I've been meaning to look into this to increase the efficiency of
- by heating system by such a damper (hopefully with an interlock)
-
- >M> This is reflected in the higher price of electricity compared to oil.
-
- >Yes, but you also have pay the man to bring the oil to your house.
-
- This is included in the price. It is still cheaper than
- heating by electricity by a wide margin.
-
- -Mike
-