Using heat from Fridge to heat water
dmdvt
| Posted in Green Products and Materials on
Has anyone thought about using the heat pump in the fridge to heat hot water?
What about a hack from a DIY ?
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Replies
Dennis,
There are several comments posted on this blog page that discuss the idea: First comment discussing refrigerator-cum-water-heater idea.
There are several problems, including these:
1. The two loads aren't matched in size.
2. The two loads aren't necessarily simultaneous.
3. Most homes can't accommodate a single large appliance that acts as a refrigerator-cum-water-heater because of the size of the appliance.
4. Combination appliances are a pain because when one part fails, both appliances fail.
I think that's a great way to increase the efficiency of the refrigerator and recapture the energy for use any time of year. the heat fro a frige is not wanted during the heating season, but in the non-heating season it could be put to better use. i agree that the loads are not balanced or necessarily required at the same time, but, you could use a secondary tank as the heat exchange reservoir that could be more easily balanced and use it as a cold water preheater for your domestic water heater. that way the recaptured energy is useful all year. just a thought.
it is also a sales nightmare to try and push two separate products at one time; that will always be the real barrier - nobody will buy it.
and we would need to do a return on investment on such a device to see if the extra costs could be recouped. this wouldn't be the first 'use something relatively free' like say venting your fridge/freezer to the outside during the cold of winter or recovering waste heat in the shower where the solution costs more than any savings.
About the only cheap and easy use for that low grade heat from the back of the fridge is an "airing cupboard". http://en.wikipedia.org/wiki/Cupboard#Airing_cupboard
Basically building the airing cupboard with a fridge size hole on one size.
I haven't tried it or seen it tried. Just an idea.