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Advice on size and brand of Hybrid (Heat Pump) Hot Water Heater

Boston_Brad | Posted in General Questions on

Hi Folks:

I’ve got a 60 gallon, indirect (oil) fired hot water heater that is on it’s way out.  I’d very much like to replace it with a Hybrid Heat Pump Hot Water Heater.

I wanted to get your thoughts on which brand was best.  And also advice on how large of a system.

I’ve got a large family with 6 people in it.  There are 5 women / teenagers in the house.   I’ve read the hybrid Heat Pump HW heaters are very efficient, but can take a while to heat up the water.  In a house of six, where we take A LOT of showers, we don’t have the time to wait, nor do we want to run out.

Do you recommend I keep with a 60 gallon, or upgrade to an 80-90?   And if I have the 60 and the old-school resistance heat coil kicks in how much will that hit my wallet a month?


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  1. walta100 | | #1

    When I looked at the spec for HPWH it looked like every model had the same BTU output the fan and the size and shape of the coil did seem to very. It seems the bigger units just store more hot water and reheat more slowly.

    Note the heat pump will deliver about 4 times the BTUs per watt as resistance element does.

    RHEEM seems to have found a ways to earn the top score in the EPA efficiency tests.

    We have seen complaints about Rheem's newest version. It seems fan makes enough noise to upset several owners.


  2. Ben_McElroy | | #2

    I just installed a Rheem 50 Gal HPWH about 3 months ago. Family of 4 (kids get half filled tub bath and 2 adults who shower every night). Been running it in heat pump only mode the whole time. Only ran low once when I took a long shower after everyone else did their bath/shower routine. Laundry migh have been going too. We have a 1.8 gpm shower head.

    I love the dehumidification value. The thing produces at least a gallon of condensate per day here in humid southern NJ (interior humidity has been very high at 65-70%, can’t imagine what it would be without the HPWH).

    The Rheem is definitely noisy. Louder than a fridge but quieter than a window a/c or dehumidifier. It also sometimes gives off a decent clatter on initial start up of the compressor. Ours is centrally located on the main floor of a 1800 sqft ranch with a louvered door that is rarely closed (doesn’t help with the noise anyways). I can hear the unit at either end of the house but it’s not bad, in my opinion.

    You might be able to get by with a 65 gal in hybrid mode plus some shower length discipline and/or low flow heads (if not already installed). This is assuming some of the kids are moving out in the next few years. If they are going to be around for a while longer, play it safe and go with the 80 gal. Just my 2 cents (from someone who is also in a female dominated house!).

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