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marthaoge
convert electric radiant heat to hydronic combined with domestic hot water?
marthaoge

I have a 60 ranch walk out basement home with electric baseboard radiant heat and an electric hot water heater. My master bathroom is on a north facing wall in zone 4 (Wisconsin). We are going to do a total gut and redo of the bathroom. I would like to convert the electric radiant baseboard to floor and wall hot water heat with an electric fired boiler located in the basement. The boiler could also be combined with domestic hot water. The size of the bathroom will be about 12' x 12' with 8' ceiling. At a later date we would also like to add the hydronic heat to the basement floor that covers about 28' x 28' with 8' ceiling. Is there a small electric boiler/domestic hot water heater that would be sized correctly for a 2 zone system (bathroom and basement) for the 1600 sq foot application? Is there a boiler that could be hung on the wall? We live next to a creek in a flood prone area so I don't want to use the electric in floor radiant heat because the basement floor sometimes gets wet. Also if we could elevate the boiler and hang it on the wall, when the creek rises we don't have to worry about anything electric in the basement getting wet. Any suggestions? And don't tell me to move because of the flooding. The area is so beautiful I can live with the occasional flood.

NashuaTech
Re: convert electric radiant heat to hydronic combined with domestic hot water?
NashuaTech

You would have to have several hydronic (hot water systems) heating contractors over to your house to evaluate the situation & recommend what is the best way to go on this project---consult the Yellow Pages under "Hydronic Heating Contractors", or Google "Best hydronic heating contractors in (your county) Wisconsin".

Since you are in an area that experiences bitter cold during the heating season, you would have to figure between 35 to 45 BTU/sq.ft (if not more) for the 1600 sq.ft. involved in this project; thus you would need a ballpark boiler with a capacity of 64,000 btu/hr or perhaps up to 72,000 but/hr (1600 X 45 btu/sq ft./1600 X 35 btu/sq.ft.)---if you could locate the boiler & a companion indirect hot water heater on the main floor, or in a specially built shed above flood waters you would avoid flood problems & use a small backup Honda generator, or similar unit, to drive the boiler system for emergency heat & light in the event of a power outage, & most importantly to avoid frozen & bursting heating pipes during an extended power outage.

If you choose forced hot water heat you run the risk of frozen heating pipes in a power outage (also an obvious danger with hydronic radiant heat as well) so a 10% solution of propylene glycol (non-toxic anti-freeze)/water would have to be used in all the heating pipes & convectors if you experience frequent power outages in winter; there is always the option of choosing a forced hot air system.

Although I dearly love & enjoy my own hydronic baseboard & cast iron radiator heating system, I live in an area (Northeast) where I've witnessed the mess & expense of other homeowners who ignored the precautions listed in this post---the frozen heating pipes crack in inaccessible wall cavities creating a real mess, very costly to repair; the house is usually uninhabitable while repairs are being done; in spite of this "Achilles heel" that is characteristic of hydronic heat, the benefits far outweigh this one liability; newer hydronic installs use Pex hi temp plastic tubing which can withstand some freezing, but most of the convectors themselves are subject to damage.

I'm not a big fan of these "wall hung" boilers because they have complex controls that often break down; it is rare to see an electric boiler, & you would probably be much better off with a gas-fired, propane-fired or #2 oil-fired unit; the indirect HWH is simply a companion tank that sits next to the boiler thru a zone & provides all the domestic hot water you'll need (30 to 40 gallon, or more capacity).

If you have available in your area propane, natural gas, or #2 fuel oil this would support the 1600 sq.ft. remodel area, & in addition act as a standby rest-of-the-house home emergency heating source in the event (probably likely in Wisconsin) of a power outage during a snow or ice storm.

Are you using wood-burning stoves now for emergency heat in the event of a power loss?

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