I have a 3 ton open loop radiant floor system. It is about 4 yrs old, and also rarely cools the house via ceiling mounted coils. (multiaqua). The well water is 52 F. The installers hooked up the desuperator to the electric hot water tank. single tank system. It did not work well, so I turned it off. The 3 ton has enough to do anyway in the dead of winter to heat the place. (2400 sq ft in Toronto area ). I looked high and low for a dedicated pre-built domestic hot water system. not much luck to my surprise. Only this heliotherm one, which is from Europe and likely expensive. http://www.heliotherm.at/ Anyone put one of these in? We spend more on water heating than on heat now! If there are no other solutions I may convert to a 2 tank system for hot water, but that will load up the 3 ton unit more. I use wood as my emergency heat when the 3 ton can't keep up. (well we have a fire every night for a few hours in the wood stove, which I think adds a lot of heat to the house). Is it worthwhile to run the 3 ton unit to make hot water via the desuperator? I can't believe there is no plug n play well sourced hot water solution - it seems a natural for the rural areas of the NE states, Canada, etc. Thanks for any comments, etc. --Tom

Almost all manufacturers have dedicated DHW water to water GSHP models. It is usually their standard unit built with a double wall vented load coil. Info is scarce as there has not been a big market for them. ClimateMaster has the THW10 rumored to be engineered by Veismann.

If you do go ahead with an additional unit consider a conventional unit staged with your existing unit and heat your DHW with an indirect water heater (one with the largest heat exchanger surface area you can find). Depending on configuration and your needs you might have to finish off with your electric water heater.

I saw units like that. The problem with them is complexity and size. Complexity in that there is additional plumbing, head scratching and general 'work'. A water heater usually runs at 4500 watts, which is about 15,000 BTU. For a geothermal I would only need about 8000 BTU, with a bigger tank, etc. To get 8000 BTU at 125F with a 52 F source It seems like one ton or less would be fine. The THW is a 3 ton. So a 100 gal tank with a one ton compressor inside it, along with all the extras, so that it has the bare minimum of connections. I guess it would need ground loop in/out and domestic cold in/ hot out, and a 240 volt 60Hz connection.

For instance the Heliotherm has an output of about 6000 BTUs and uses 600 watts of electricity. That would actually do it for us if the tank was big enough. Theirs is a 60 gal tank.

I see your point of the indirect hot water thing - that will cut down on mineralization.

I may just break down and go with the two tank desuperator - but it only works when there is heating or cooling demand.

Thanks,

--Tom

I had one of these installed along with my FHP system. http://heat2o.com/index.html

It has been installed for almost two years and so far it has worked great.

My installer is here: http://www.owenscomfortsystems.com

Hope this helps.


Regards,

Mark

Waterfurnace EWO20 is worth a look. Most codes want a double wall and vented heat exchanger for DHW service