Solar hydronic under floor heating

Discussion in 'Development' started by Lizzie, 10th Jun, 2018.

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  1. Lizzie

    Lizzie Well-Known Member

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    Planning the build of our next house - which may be a couple of years away - but already thinking about factors that need to be incorporated "during" the build.

    Would love to put in under floor heating throughout the house, via either hydronic (water via solar powered heat pump) or mesh with a separate solar power supply due the power required for a whole house.

    I'm leaning towards the hydronic as the system can be used for cooling in summer.

    Has anyone installed either/or and any recommendations of which way to lean - and reading?
     
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  2. Erica

    Erica Well-Known Member

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    @Lizzie did you chose a system? What did you go for? - I'm just starting the same investigation for my new build. A friend building in Adelaide hills (so cold!) is going for hydronic in-slab heating throughout the entire house (250m sq of living), water to be heated by an electric heat pump (pump located inside in a linen cupboard) and electricity generated by solar roof panels (big system to supply all of the household needs during the day).
     
  3. Lizzie

    Lizzie Well-Known Member

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    We're not renovating that property (currently tenanted) until this time next year ... so still stewing in the back of the mind.

    Because it's a full reno I'll be putting three phase power on - which means a double (13kw) solar system plus hot water and I might run out of roof space - so will talk to the experts as to whether it's best simply to go electric under floor heating with the amount of electricity we'll be producing, or hydronic.

    Emotionally I'd rather to hydronic - but practicalities will prevail. Love to hear how your friends went. I got relatives in NZ who have a hydronic system that runs off the wetback of their fireplace - under the slab floor - thru the towel rails - back to the fireplace (which his a whiskey still on top) and they love it - both the heating and still
     
  4. spludgey

    spludgey Well-Known Member

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    It will be far cheaper and more versatile if you get solar PV (regular panels) and then run a (reversible) heat pump with the power.
    Look at getting 3 phase and a minimum of 13.2kW of solar, but ideally more.
    In NSW (where you live, so I assume that's where the house will be), you're best off putting as many solar panels on your roof as you can, even if they're south facing they'll pay back.
    You should consider solar with your roof design as well. Have as few surfaces/faces as possible and if you can, face as much of the roof north as possible. Locate stink pipes and antenna (if you still need it in this day and age) as far south as possible.

    Edit: while typing this, I read your reply above. Maximise solar PV over hot water, it's much cheaper. With 3 phase, you'll be able to connect up to 30kW in NSW without a special application.

    Buy the way, I work with solar as part of my job, so if you have any questions, please feel free to ask.
     
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  5. euro73

    euro73 Well-Known Member Business Member

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    We used this in our 3 bathrooms and laundry - works great

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  6. Lizzie

    Lizzie Well-Known Member

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    Being a greenie at heart - I'm all over it :D
     
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  7. Paul Mete

    Paul Mete Well-Known Member

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    Our experience is that in-slab hydronic will not use conventional solar heated water and is fussy about the water it allows in its system to avoid blockages. So you are right in thinking of a heat pump system.
    We suggest a high performance solar passive design for any new home to compliment these active measures and cooling may not be needed. If needed it may be minimal. Power generation via. PV cells and the need for aircon cooling coincide (sunny days) so it makes sense to save on the cost of your system and simply power a simple cooler through power generation on a well designed house.

    PAUL
     
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