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Community and Q&A

Best source for domestic hot water?

aekatz | Posted in Mechanicals on

Getting ready to build a LEED certified home, tight construction, excellent quality windows. Ground Source Heat Pump based HVAC. Will use excess heat from heat pump for hot water, but need a storage/booster tank. HVAC contractor wants to use standard resistance tank heater. Is this sufficient? How do I best find a highly insulated tank? Essentially no one in my area of the country (Northeast Indiana) is building like this. Heat Pump tank? My HVAC contractor says that a demand heater would be too expensive/relatively useless as the water coming from the heat pump should be more than sufficient most of the year, and the tank is justly used as an insulated reservoir. I have “just enough knowledge to be dangerous not helpful”. When we first sat down with our architect, he said that “…building green was a series of difficult compromises”. This house is, in part, to be a demonstration of what can/should be done, yet we do need to be somewhat practical. Yet we are trying to keep electrical loads as low as possible.

Any suggestions?

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  1. GBA Editor
    Martin Holladay | | #1

    In your situation, a standard electric-resistance water heater is the appropriate tank. It provides storage as well as a backup source of heating. There is no need to invest in a heat-pump water heater, since you already have a heat pump.

  2. user-2890856 | | #2

    Andrew , I concur with the caveat that this tank should be insulated well and be of good quality . Hard to find in the standard electric offerings of almost all manufacturers . There is one manufacturer that gets it however , HTP in East Freetown Mass has your heater , Look up the Everlast water heater . It has an EF of .91 , 2-3 inches of water blown foam insulation , 316 L SS tank , no anode rods needed for this reason , low wattage 3,000 or 4,000 elements and a lifetime warranty .
    Within a budget and wanting to do the best you can this is the heater you want .

  3. badgerboilerMN | | #3

    We use the Rheem Marathon, by far the lowest standby losses and available in the 105 gallon model I have to take advantage of my off-peak rates.

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