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Solar HW system: Comments?

jp_2 Member Posts: 1,935
thats odd?

you will not be able to extract any more heat than the panles can produce within a day. I do not think the heat pump will ever pay for itself?

if you need higher temps, use a smaller storage tank.


  • Bart Nathan
    Bart Nathan Member Posts: 6
    Solar HW system: Comments?

    We live in central Virginia and have 3200 sqft house (well insulated). We already heat with hydronic radiant heat and with propane (high efficiency) as the power source. We want to add solar HW to the system to help with winter heating and DHW, especially in light of the tax credits, the skyrocketing cost of propane and other tangibles and intangibles.

    Anyway, we have gotten a quote for a system. I am pasting the text below of the system:

    "The solar system provides active solar hydronic heat collection and storage using American Energy Technology 4’ x 10’ solar panels with black crystal coating, and a drainback heat storage tank with DHW heat coils. The system uses a drainback design to eliminate potential for overheating, freezing and nighttime losses. The heat storage module is an unpressurized, polyethylene tank with copper coils for the domestic hot water and integrates with the radiant system. The price includes 5 AET panels with flush mounting hardware for direct mounting to the roof and solarsil flexible couplings, the Delta T control, the storage tank, bronze solar pump. and tubing & insulation from the roof to the mechanical room. The panels are planned to be flush mounted to the garage roof. Included is a 1 ½ton heat pump to raise the solar supply temps to make optimal use of solar panels in the heating season."

    Cost: $11,000 (NOT INCLUDING LABOR)

    Now some questions:
    1) General thoughts on this system?
    2) Are 5 4x10 panels enough? Too much?
    3)What about the heat pump? Seems like overkill to me, though our water is from a well and pretty cold.
    4) Is the cost reasonable for this system?
    5) Is a simpler solution practical?


  • hot_rod
    hot_rod Member Posts: 22,254
    Have the contractor

    run an F-Chart analysis for you.

    It will show percentage of load able to be handled, Fuel Savings, Life Cycle Savings, Life Cycle Cost, and an Economic Summary, among other reports to see if this fits your budget and expectations.

    hot rod
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Bart Nathan
    Bart Nathan Member Posts: 6

    I'll see if he did it already or can do it.

  • Kevin_in_Denver_2
    Kevin_in_Denver_2 Member Posts: 588
    Temp limit of poly tank

    A polyethylene tank probably has a max. operating temp. of 160?

    It wouldn't surprise me if labor doubled the cost, so that's something you need to know.

    There was an error rendering this rich post.

  • Bart Nathan
    Bart Nathan Member Posts: 6
    What kind of tank

    is better/stores higher temps? What would the price differential be?

    Thanks for the heads up on the labor.

This discussion has been closed.