Heating Domestic Water

beatle78 · Post by **beatle78** » Sun. Mar. 30, 2008 7:52 pm

So what boilers are insulated and what boilers are not?

Yanche · Post by **Yanche** » Sun. Mar. 30, 2008 9:59 pm

europachris wrote:Now that summer is approaching - I have this nagging question regarding heating domestic hot water all year round with coal.... SNIP ...

Most modern homes are well insulated and have central A/C. While running coal to heat hot water might save $ per BTU, that would be offset, IMHO, by the extra cost to run the A/C to remove the extra heat load from the idling coal fire. ...SNIP... Chris

The energy efficient way to heat domestic hot water during the summer time in centrally air conditioned homes is to have a de-superheater on the air conditioning compressor. This is a system that removes some of the heat that normally goes to your outdoor condensing col and through another heat exchanger produces hot water. This hot water is then used as the supply water to an indirect hot water heater. The additional operating costs over central air conditioning are low, the equipment capital equipment cost are high.

Post by **Richard S.** » Sun. Mar. 30, 2008 10:22 pm

beatle78 wrote:So what boilers are insulated and what boilers are not?

Probably any boiler, the Keystoker eouropachris has is a hot air/radiant stoker with a hot water coil.

All the EFM boilers will be insulated and I'm sure the Keystokers are too. The AA's and the AHS I don't know about but I'd doubt they aren't.

beatle78 · Post by **beatle78** » Mon. Mar. 31, 2008 12:02 pm

Richard S. wrote:
beatle78 wrote:So what boilers are insulated and what boilers are not?
Probably any boiler, the Keystoker eouropachris has is a hot air/radiant stoker with a hot water coil.

All the EFM boilers will be insulated and I'm sure the Keystokers are too. The AA's and the AHS I don't know about but I'd doubt they aren't.

Thanks Rich.

The Harman boiler must be insulated as well, then?

Does anyone know of a boiler that is NOT insulated? That way I can scratch that off my list of boilers.

Yanche · Post by **Yanche** » Mon. Mar. 31, 2008 1:44 pm

beatle78 wrote:So what boilers are insulated and what boilers are not?

The A-A Anthratube is normally not insulated, insulation was an option. The AHS Coalgun is insulated. But don't make the lack of insulation a big decision factor. Most boilers have poor insulation compared to the insulation in a modern hot water heater. More important to low summertime loss is how hot the boiler water is and does it have to be kept at the desired temperature all the time because the domestic hot water coil is in the boiler.

Highlander · Post by **Highlander** » Mon. Mar. 31, 2008 2:57 pm

The Harman boiler, is not insulated as it comes from the factory. I added a small amount of fiberglass under my sheet metal covers which helps somewhat, but it still radiates quite a bit of heat.

Scottscoaled · Post by **Scottscoaled** » Wed. Apr. 02, 2008 12:17 am

Here is how I'm figuring losses. The Keep it going timer will be set at 2.5 minutes per half hour. Thats 120 minutes per day. Thats 3600 minutes per month. May, June, july, Aug.,Sept. That's 18,000 minutes or 300 hours. My boiler is set to run at a feed rate of 10 lbs per hour. That's 3000 lbs of coal to keep it running. We use most of our water in the morning so an additional 5 lbs of coal per day would be an extra 750 lbs. For less than 2-ton of coal @ $210 per ton is still way cheaper than the 300 gallons of fuel oil (more like 400) that we usually use. With a good drafting chimney, the timer could be set for half that amount. As far as air conditioning, I'm sure that any additional heat generated wouldn't be an issue until the summer months. Even then, the savings would probly cover the electricity costs for the pool and the a/c. Just the way I'm figuring. Going to find out pretty quick!

Scott