horizontal water heater

Anyone make a horizontal tank electric water heater? Preferably a heat pump hybrid based unit.

Lots of reasons I dont need to bore you with why I want to put it where I do, but the ideal space for this would be about 5' from where my new geothermal exchanger is going. I cant put it immediately next to my geothermal exchanger cause my breaker boxes are there and code wont allow it to fit.

That space feet away is under a small deck like area that leads up to my back door... approx 3' height clearance, but its about 6' wide and 8' deep. Its a 4 bedroom house, so the low boy units arent really big enough and would be harder to service with multiple of them under this deck.

I'd like to setup two tanks under this space... one that is fed off the geothermal as a pre-heat tank (no power), that ultimately feeds into the other that is powered. I should be able to easily fit a couple of 80 gallon tanks in this space if anyone made them in a variety than can be mounted horizontally.


I have no access to gas at my place, but also considering an alternative to use a tankless electric heater in a booster fashion. Its less than 10' from my breaker box and I have 400A of service, so wiring would be easy. I'm in a cooling dominated area and the geothermal unit i'm going with is known to produce 100-115 degree water pretty easily at more than 20 gallons per hour, so hopefully wouldnt even have to run the tankless unit most of the year (only during the cold months maybe if the geothermal doesnt produce enough heat to both heat the house and the water).

Anywhere have efficiency comparisons of electric tankless vs standard electic vs heat pump hybrid?

For the pre-heat tank, there are lots of indirect WH that you could use. Never saw an electric one in that configuration, though (doesn't mean they don't exist). The temperature gradient works better on a taller tank. I think you'd lose more capacity with a horizontal tank, since the colder bottom water would be closer...less gradient, and therefore, you'd be unable to get as much out before the hotter top water was cooled off.

A heat pump hybrid version may not be all that efficient if it gets cold there...might be fine if it is a mild climate. Tankless needs LOTS of amps. Not sure what you have that you installed a 400A service, but an electric tankless might need a lot of that, so it would depend on what your 'normal' load is.

Propane may be an option, if NG isn't available.

The problem I'm really having is finding someone that makes a horizontal residential electric WH. I can find tons that make industrial WH, but they are cost prohibitive and just overkill. Do you know of any companies that make these?

NG isnt even close to me... gas company actually laughed a bit at how far away it was. And I'm not really into propane... just dont want to go there as theres not really a great place to put the storage tank on my property.

I'm in a cooling dominated environment in SE US (80 degrees by march and can last into december - snow that melts by the next day only a few times a year). So the geo unit should make its maximum amount and any sort of heat pump WH will have plenty of heat to remove from the environment. Its also in my garage, so no worries about removing heat from the house in the few colder months of the hear.

The geo manufacturer says to use a direct WH and tee the cold water input immediately above the WH and run that over to the geo unit. And then run the geo unit hot out back into the WH drain valve with another tee directly off the WH. So it essentialy sucks water out the WH cold inlet at the top and pumps it back in the back in the bottom through the drain out.

So its really setup for a two tank system since there will essentially be a uniform temp in the pre-heat tank due to hot water rises up over colder water through bottom entry into the pre-heat tank. Essentially, there is very little gradient in the pre-heat tank, so horizontal should be fine for that.

I currently have a shortty tank (40 gal give or take) crammed into a closet under my stairs, so probably not getting much benefit from gradient anyway since its more or less the same height as what my horzontal tank would be.