Since 1968 I have been heating my home with a oil fired hot water boiler==baseboard heat. I would like to change my source of heat to electric. Any suggestion or ideas
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Are you aware that in most locations, heating water with electricity will cost about three times more than gas? I do not know why you want to change but...what you propose will be very expensive.
Last house we lived in was like that. When my wife bought the place (before me), it was oil fired hw; after the system died and filled the house with oily soot and the insurance co had to have EVERYTHING in the place cleaned, she went electric hw.
However, think about your options and cost. Electric is typically most expensive; oil or nat gas tends to be cheaper. if available, my pref would be nat gas; it's clean and easy.
"Electric probably less than half again as much" Probably not. Check to be sure, but my very cheap electricity is twice the cost of not-very-competitive fuel oil. A 3-fold difference is common.
But, to answer your question. It is very hard to beat hot water heaters for code-approved, pressure rated, sources of hot water. If your baseboards can operate at 140-160, then installing 2 or 3 EHWH might do it. Obviously, your heat demand needs to calculated/estimated first, regardless of what electric option you select. "tankless" hot water heaters take up less space and are higher wattage. But, like otehr HWH, have limit between 140 and 160 on their thermostat. A purpose-built electric boiler should give you 180F which is a common design criteria for baseboard heaters.
Note that your electrical service (utility drop, meter head, distribution panel ("breaker box"), and conductors to your utility room will all have to be upgraded to accomodate the increased current demands.
Just some numbers to think about: a 40kW electric boiler at 240-1-60 power will require 167 A and produce 136,000 Btu/hr of useable heat, enough to heat an average 3000 sf house. If the boiler operates at full load 25% of the winter and electricty cost you $0.06 kwh, (national average is $0.08) you will pay $1340 to heat your home for 3 months.
Consider water/water ground source heat pump, then operating cost can be below gas/oil - you likely have undersized existing baseboard for that though.
Tankless hw heaters not allowed for this application on all mfg specs I've seen.
remodeler
I'm with JunkHound in thinking ground source heat would be best, if you have to go electric. Where are you located? If you're in a location where AC is also used, it would make both heating and cooling more efficient.
Why didn't Noah swat those two mosquitoes?
remodeler: "Tankless hw heaters not allowed for this application on all mfg specs I've seen."
Agreed. That doesn't mean it doesn't work just fine. A lot of tanked HWH's aren't spec'd for space heating applications either, (although some are - with no discrenible difference in construction). My sense is that the manufacturers are just trying to avoid liability in what is, admittedly, an uncommon application and therefore one which a mediocre plumber could get wrong.
I sometimes use my hammer contrary to the instructions, too. But so far the Stanley Hammer police haven't thrown me up against the wall.
David Thomas Overlooking Cook Inlet in Kenai, Alaska
Edited 1/31/2003 11:11:55 AM ET by David Thomas
FWIW - I was suggesting that the guy go with a forced air system, not stick with baseboards.Try praising your wife even if it does frighten her at first.
BTW, there is a tankless heater that is designed just for that application. I forgot the name, but I think that it is German.
I saw it on Bob Vila show. What they where touting was a "boiler on the wall". Some distributor was putting these systems together. I combined the tankless heater along with the pumps, manifolds, and valves. All on a carrier and it is just bolted to the wall.
"there is a tankless heater for that application" "boiler on the wall"
Nice. Especially in heating systems, I think a lot of designers miss an opportunity to add value. If floor space costs $100 - $200 per square foot to build and then something to heat (forever more); then saving 20 square feet is a chunk of change. My own domestic hot water, RFH, forced air, and HRV are all in a 3' x 4.5' closet. With enough space for access and service.
David Thomas Overlooking Cook Inlet in Kenai, Alaska
>>I sometimes use my hammer contrary to the instructions, too.
That must be one cold hammer (kenai, alaska). how long's your work season?
I have experience with gas instant-ons, they would be unsuitable in radiant system because they are triggered by water flow and stricly do not allow preheated water because it screws with their delta-t (trips the blow-off valve). I don't know much about the electric ones, I am a little distrustful that they could get so much temp rise out of an electrical heating element, though I saw they have a huge amp draw.
I am amazed every morning by my coffee maker. What an improvement on percolating.
remodeler
Agreed, flow rate and delta-T would be issues, but with enough flow rate, the delta-T problem would be eliminated. I can see ways around those problems, especially if the tubing in the slab hasn't been spec'd yet (bigger tubing, shorter loops, bigger pump). But control would be tricky. Really easy to hit a zone with too many BTUs before the T-stat noticed what was going on. You might need to install an interval timer (e.g. upon rising voltage, open for 10 minutes, close for an hour) so the T-stat would have time to notice the heat that had been added. Then the pumping time (10 minutes in this example) could be tuned for loop size and adjust longer and short for cooler and warmer outdoor temps.
But definitely a far trickier installation that a tanked HWH or a standard boiler. Easiest way to use tankless might be to the tankless keep a tanked HWH to temp and distribute from the tanked HWH. Thereby eliminating an advantage the tankless had.
David Thomas Overlooking Cook Inlet in Kenai, Alaska
Ground water source is a good idea and some of it is being used in this state. Most heating contractors want to go the ground loop system but they only want to trench down about 5 feet. I dont think that is deep enough and will cause the standby source to come on in extreme cold weather . They need to trnch down about 8 feet but that raisses the cost way up. Water to water would mean I would need another well about 60 feet deep that would give me a endless source of water. I have a legal place to dump the used water.
Back at the beginning of World war I .I was in Noth Dak. When the war started oil was hard to come by. Alocal dude who tinkered had a oil fired boiler and he simply pulled out the oil burner unit and slipped in a electric coil about 3 in in dia and a foot long, changed some controls and lived happily ever after. Electric was not a problem because it was generated locally by a coal fired steam generating system. The coal ws a local low grade type mined locally and cost about 50 cents a ton. Of course he plugged up the chimney. I cant find any one who thinks that would work but it did.
none
I don't think you want to go GeoSource heat pumps with baseboards as you could not run them at a high enough temp for your existing baseboards. And if you could your c.o.p. (coeffient of performance) would be to high to make economic sense. My suggestion would be a Viessman Vitodens wall mount condensing boiler if you can run with nat. gas or propane. Or the Vitola 200 in oil fired.