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solar tanks

radmix Member Posts: 194
Im looking for a solar tank that does DHW inlet and out, Coil for solar, Coil for Boiler and a Coil for space heating. There will be two tanks both 119 gallons




  • Fortunat
    Fortunat Member Posts: 103
    not triple coil but the same idea

    There are a bunch of tanks now for sale in US that are designed for solar combi systems. I haven't seen any actual triple coil tanks here yet, but these multi tap tank in tank water heaters do essentially the same thing.

    -Wagner CombiPro 450

    -Buderus Logalux PL750/2S

    -Triangle Tube Smart Multi Energy Tank

    Any of these would probably be suitable for what you want to do. Because the outside tank is full of boiler water and has lots of different tappings it allows you to tap in for the boiler and even multiple different space heating temperatures at the same time.


  • hot_rod
    hot_rod Member Posts: 22,261
    plenty of dual coil

    tanks on the market, some with electric element backup.  The upper coil, properly piped, maybe with a 3 way zone valve, should be able to double as boiler input or heat output.

    Typically the upper coil can supply energy to the heating load until it drops to a low temperature. Then the boiler kicks in to cover the load and bypass the tank to allow solar contribution to a cold tank.  But you still need to provide DHW under any condition.

    There will be some compromise when trying to use a single tank system to provide DHW, solar input, heating load, and boiler input.

    A dual tank system with a solar control that has priority logic options is another method to consider.  That can help maximize the solar contribution by selecting the best, coldest load to present to the collector array.


    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,336
    Is the water...

    ... in the tank being used for anything other than storage?  Is it under pressure?  If not under pressure, you could use an insulated plastic tank for storage.

    Yours,  Larry
  • Tom in Maine
    Tom in Maine Member Posts: 23
    edited October 2011
    Another option

    We make 200g and up tanks that can have whatever you need for hx.

    If you are tying two 119g tanks together, this might be an alternative.

    Sorry for the commercial, but it is a fair bit less expensive and more serviceable.

    Tom in Maine
    Tom Gocze
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