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Sub-floor radiant heating or baseboard radiators for 500 ft 3rd floor apt?

Caleb Member Posts: 22
I just bought a home that needs new heat on the top floor apartment. It is small 1 bedroom about 500 S.F. I am looking for best way to heat the place with city gas available at the meter. I like the gas fired wall hanging heaters that I have a place for and get good gov't incentives. I found one (triangle) that also has dom. hot water (DHW) in one boiler. Can I use this with pex lines on the baseboard to supply heaters in bedroom, Kitchen/dining, living, and bathroom rooms? But today I was just reading about warmboard and similar items that would run pex on the floor to heat whole house. Can I do this in bathroom under tile and under laminate floating floor? I read it only uses 90degF water so it operates boiler at best efficiency.

Lastly, is this overkill since there is a second floor apartment below the floor that is heated separately? I could probably get away with elecreic space heaters given the small space, but how do I calculate the cost differences?

Thanks for reading and any advice.




  • SWEI
    SWEI Member Posts: 7,356
    heat loss calculation

    will be necessary to properly size the boiler.  The Triangle Tube PE110 will probably be about 8-10x bigger than you need for that space alone.

    What kind of heating system (and source) serves the rest of the building?  Did it used to heat the 3rd floor as well?
  • Caleb
    Caleb Member Posts: 22
    went with Electric instead of gas

    Went with an electric mini split for heat and also provide A/C in summers on top floor. First winter was a little cold with just one indoor unit and 3 rooms all without insulation. Last summer blew in cellulose insulation and this winter much nicer. Holds heat in far away rooms much better.