Pennsylvania Question on water heater with geothermal

Discussion in 'General Discussions' started by cwb124, Apr 17, 2017.

  1. cwb124

    cwb124 New Member

    Not 100% geothermal related but hoping someone here could guide me in the right direction. I had a Climatemaster Tranquility unit installed this past summer with the desuperheater. As part of the install they put the 50 gal 'dummy' electric tank and hooked that to my existing 80 gal propane water heater.

    Well that propane water heater is now dead and I'm looking to replace it. What would be the ideal (in terms of efficiency and budget) replacement? Should I just do a straight swap for an 80 gal propane tank? Should I go smaller since I have the 50 gal holding tank? Should I go electric, or maybe tankless propane? We have never run out of hot water and I don't want to start now. There's 5 of us in the house, and 3 of them are girls. I guess I am just not sure how, or if that 50 gal holding tank should change my decision making on replacing the water heater. Thanks!
     
  2. arkie6

    arkie6 Active Member Forum Leader

    You can't really count on the 50 gallon geothermal buffer tank measurably increasing your overall hot water capacity because during mild weather when the geothermal unit is not running or running infrequently, the buffer tank won't be heated.

    Given your statement "We have never run out of hot water and I don't want to start now. There's 5 of us in the house, and 3 of them are girls.", I would probably stick with an 80 gallon primary water heater. I'm not sold on tankless water heaters and some (most?) aren't recommended to accept pre-heated water which is what your 50 gallon buffer tank will be providing when the geothermal unit is running frequently.

    From this link: https://learn.compactappliance.com/tankless-water-heater-sizing/

    "Note: tankless water heaters are intended to heat potable (drinking) water only and the inlet water to a tankless unit should not be pre-heated."

    Now the question is whether to stick with propane or go with conventional electric resistance or electric heat pump water heater.

    Gas fired water heaters have faster recovery than electric or heat pump water heaters.

    Gas fired water heaters have higher heat losses than electric water heaters. If the water heater is located in the conditioned space, this will aid in the wintertime when heating the home, but add additional heat load in the summer.

    With the variability of propane prices, it is difficult to predict the long term cost advantage of propane vs. electric.

    An electric heat pump water heater would likely have the lowest operating cost, but higher up front purchase cost. Heat pump water heaters also need a relatively large area to draw heat from, so if your water heater is located in a small room or closet, that won't work for a heat pump water heater. A disadvantage is that the heat pump water heater draws heat from the air around it so in the winter time it adds to your homes heat load but with a high efficiency geothermal unit heating your home this should not adversely affect cost to operate unless your geothermal unit is marginal or undersized. A plus is that in the summer, the heat pump water heater cools and dehumidifies the air around it. This can be an advantage especially if the water heater is located in a damp basement.

    Is the water heater the only propane appliance you currently have? If so, switching to electric might allow you to completely eliminate propane from your home.

    An advantage of propane is that most water heaters can operate during electric power outages if that is a common concern in your area.
     
  3. cwb124

    cwb124 New Member

    That is awesome info. Had no idea tankless heaters shouldn't accept pre heated water. Good to know.

    If I were to go with electric water heater I would indeed be no longer using any propane items. I am however in the future considering a propane whole house generator and possibly a gas cook top in the kitchen. I would be worried about the recovery time of the electric tank though. We've been very happy with the propane heater so I may just stick with that. Negative of the heat pump electric is it throw cold air out and I'm planning on fishing a part of the basement and would rather not have to fight against that extra cold air.
     
  4. Deuce

    Deuce Member

    Most electric water heaters have about a 45 minute recovery time I think.
     
  5. cwb124

    cwb124 New Member

    Yeah my understanding is propane can recover about 2x as fast. Also, for the last couple years I've been getting propane at around $1.00-$1.30/gallon since I own my own tank. Looks like propane has to be around $3.40 for electric to be more cost effective based on a couple calculators out there. Think I'll just do a straight swap. Thanks for the insight, awesome info as usual from this board.
     
  6. mtrentw

    mtrentw Active Member Industry Professional Forum Leader

    A challenge I ran into when getting off oil and all electric was the spare capacity I had in my electric panel. You may not be able to support the additional load of an electric water heater.
     
  7. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

  8. Bablu

    Bablu New Member

  9. johnny1720

    johnny1720 Member

    I have a Reheem tankless hot water heater that is attached to my Desuper Heater. There are 5 people in my house and three are ladies. Prior to haveing the geothermal installed I filled the propane tank 3 times a year. I now fill it 2 times per year. I pay a bunch for propane probably close to $3.00 per gallon. What ever I pay is totally worth it to have unlimited hot water. I power wash vehicles in the winter with hot water, I occasionally fill the kids little pool with warm water. Two years ago I used 150 degree water to break down a few ice dams on my roof. I normally don’t get ice dams but that was a very bad winter.

    I pay close to $500 per year just for hot water.
     
  10. gohole

    gohole New Member

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