Does anyone have updated (current product information) on water heaters with heat pumps?
CASUDI
| Posted in Green Products and Materials on
I am looking for a DHW heater (with heat pump) which will service both DHW and a radiant floor system? The project in question has approximately 1300 sf radiant floor system and having one appliance to service both efficiently would be very beneficial.
I’ve looked at the Sanden Eco (good information here in this forum) but it’s too late for the current project to design an exterior heat pump into the residence exterior; but I will certainly consider this next for future cleints since they will be available (I’m told) at the end of this year.
When I searched here I could only find older information.
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No data, but food for thought - the combination does not sound ideal. The lower the heat difference between source and sink, the more efficient a heat pump can work. DHW requires fairly high temperatures, notoriously poor COP. A radiant floor works at much lower temperatures, where a heat pump can work much more efficiently, good COP.
From a thermodynamics point of view you are better off splitting the functions, or at least have separate heat storage for the two functions. 1300 sf is a pretty decent area.
Caroline,
First of all, you can't use a heat pump for space heating unless the compressor is located outdoors. So you can cross most heat-pump water heaters off your list.
In addition to the recently introduced Sanden Eco -- an appliance that may or may not have the heating capacity you seek -- you could consider using the Daikin Altherma.
Other brands of similar appliances exist, but they don't have a distribution or support network in the U.S., so they have to be directly imported from Asia -- which is not a good approach if you have future maintenance problems.
Daikin Altherma heat pump units are available in high temperature format for DHW and low temperature format for infloor heating but they do not appear to offer a single heat pump unit which performs both functions. They do offer a hybrid unit which includes a gas boiler for the DHW side. And Martin's point cannot be made strongly enough, that for any heat pump used for space heating the compressor HAS to go on the outside: it should also be obvious but I will state it anyway, a heat pump water heater installed on the interior of the home will rob heat from the space where it is located and add to the winter heating load. If you are fortunate enough to live in a location without an appreciable winter heating load, this may not be a problem. Otherwise, beware. There's no free lunch in the world of home energy systems.
Caroline ,
1300 sf is pretty vague . how many BTUh is the design load and what temp water does your radiant require at design and in the shoulder seasons ?
What fuels are available to you and what is your location ? Do you require electric only operation ? Maybe you could look into these units .
http://water.nyle.com/wp-content/uploads/2015/06/GeyserCCHPSeries-2015.pdf
More information would certainly help