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CB in MN
Worth swapping out electric baseboard?

I am experiencing my first winter in my new Minneapolis, MN home. The house is heated with a gas boiler and baseboard heaters which work well. However the previous owners converted the attic space into a master suite and installed an electric baseboard heater with its own thermostat. They claim to have insulated as best they could when they did the conversion, but it is absolutely freezing up there and we end up keeping the electric baseboard at 70 degrees all night.

I have heard that electric baseboards are electricity hogs - is that true? Am I burning through money by leaving it on almost 24/7? Also, I think I could run water pipes up from the basement which would give me a standard hot water baseboard in the master suite which I could then zone. Would it be worth it?

NEC
Re: Worth swapping out electric baseboard?

Your electric BB "probably" runs at 250watts per foot. What do you pay for a kWH of electricity by the time all of the extras are tacked on? From there it is pretty simple to figure out what it costs to run the BB.

NashuaTech
Re: Worth swapping out electric baseboard?

I agree with NEC---it's probably costing you several hundred $$$ per week to run the elec. baseboard, and it still isn't doing the job of heating that you need.

Yes, an extension of the gas-fired hydronic baseboard would be an excellent solution---provided several elements are present:

1) they can run at least one 3/4" supply and one 3/4" flexible plastic PEX pipe return line up there from the boiler.

2) the gas boiler has sufficient reserve btu capacity to add on the attic heat load.

3) the attic exterior walls have sufficient insulation to adequately hold the heat---insulation can be blown in from the outside by removing a shingle or piece of siding here & there to blow in cellulose insulation if you need it for a few hundred $$$----this is well worth the expense if there is no insulation in the attic exterior walls now.

They have a 3/4" plastic PEX tubing now that can withstand hi temps of at least 200 degrees & is usually flexible enough to run it up wall cavities, drain chases or chimney chases to get it up to the attic location----BUT, it may involve opening a wall cavity here & there if they run into several "firestops" (crossbrace wood members inside the walls that block vertical access to the attic, except in "balloon" framing construction).

Most boilers have adequate reserve capacity to "add on" an additional zone---you will have to calculate the present HEAT LOSS of the attic addition and document the btu/hour OUTPUT of the boiler.

For a rough estimate, take the entire sq. footage of the attic addition rooms and multiply by 40 to get a rough estimate of the heat loss per hour.

Thus a 700 sq.ft. attic apt X 40 = 28,000 btu/hour as the heat loss & additional amount of btu/hr the boiler would have to supply to the attic (if there are a lot of single pane or drafty windows up there or little or no insulation, multiply by 50 or 60 instead of 40).

Check the NAMETAG LABEL on the boiler for the total BTU/HR OUTPUT of the boiler (usually a DOE or IBR number).

You would have to calculate the heat loss for the lower level apts doing a similar calculation to determine how many btu/hour are needed for the lower apts to see if there is sufficient reserve capacity for the boiler to heat the attic apt.(there usually is sufficient reserve).

Consult the Yellow Pages under "Heating contractors" to get several estimates for the cost of the conversion.

Let us know how you make out---you can usually save big $$$ by doing this type of conversion.

CB in MN
Re: Worth swapping out electric baseboard?

Thanks so much for the advice. Is there an 'easy' way of knowing whether the previous owners did indeed insulate the exterior walls and whether it is sufficient? I guess I could cut a hole into the drywall and see what I find!

I'll do the calculations and see whether my system can cope with the extra load. Our boiler is a 40 yr old Peerless which some time soon we will replace, so I'm thinking when we do that we could have them do the extra pipework. Will let you know how I get on.

NashuaTech
Re: Worth swapping out electric baseboard?

Yes, no need to cut a hole in the sheetrock to check for wall insulation---one trick is to unscrew the cover plates of the electrical wall outlet receptacles (exterior walls only) & take a flashlight & small inspection mirror to see if you can see any insulation---you can often feel cold airflow with your hand if there is none---you may have to unscrew & remove the steel/plastic receptacle box itself (keep the wire attached) to get a good look in the wall cavity.

Take a wire hanger & unravel it & put some glue on one end & insert it in the cavity (turn off the electric power to the attic if you are working near any wires) to see if you get any insulation on the glued end---if you can hear the hanger wire rattling around when you twist it, you can assume there is no insulation inside the walls.

Also drill some small holes in inconspicuous areas & run the glued hanger wire in as before to see if you get any insulation---the drilled holes can later be filled with caulking compound.

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