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radiant floor heat in hydronic return line?

daver
daver Member Posts: 1
Probably been asked before, but is the temperature drop from a cast-iron radiator hydronic system enough (or be made enough) that the return could be used as a radiant floor?

Comments

  • SWEI
    SWEI Member Posts: 7,356
    It could be, depending on the sizing and ΔT of both. A set of closely spaced tees on the return line from the radiators will allow you to keep a 10-15˚F ΔT on the floor while running the radiators at 25-30˚F ΔT.
  • Paul Pollets
    Paul Pollets Member Posts: 3,663
    Try the Oventrop UniBox to turn radiator temps into appropriate RFH temps. The UniBox can provide up to 12K Btu's for a small radiant zone. Typically, a radiator is removed and the UniBox pipes from the old radiator stubs. A circ pump is not required.
  • SWEI
    SWEI Member Posts: 7,356
    Had to go look that one up. http://www.oventrop-us.com/catalog/pc/viewCategories.asp?idCategory=15
    Interesting. Which model are you using?
  • MikeG
    MikeG Member Posts: 169
    I'm thinking about doing the same type of thing. Currently I have a 15x24 family room with copper finned BB. Well insulated, tight, good windows over a good access crawl space. The underfloor insulation is not up to standards so I know that is part of the issue. I'm running about 150* water now. Rest of the house is mostly BB with utility room radiant floor and ceiling with thermostatic mixing valve. The supply and return 3/4" copper lines feeding the family room are run in a joist bay about 4" below the floor. With insulation under them. It's a sealed joist bay. Floor is 3/4" TG OSB with 5/8" maple. My wife really likes standing over that joist bay. I plan on installing extruded plates and O2 pex this summer and reinsulating, just to do some floor warming. Im trying to plan out the best way to do that. I did not want to run another zone for that. This room was newer construction attached to a 100+ year old farm house. I'm not totaly understanding how the Oventrop works. I thought about cutting in close tees and putting a circ under the crawl with a thermostaic valve. Looking at all options. If I just insulated it would probably be fine, but I don't mind the expense for comfort. We spend most of our time in that room. Just looking for options. Thanks to all