Radiant heat

[MasterPlumbersKeymaster]

I want to remove some copper bsbd
in the kitchen;(3 ext. walls & sep roof)this room is COLD. The rest of the rads in the house are cast iron. Can I just put a separate circulator and zone valve & Tstat with radiant hose in the joists below, will this work?

[Harold KestenholzParticipant]

Radiant floors give off about 30 btuh of heat per square foot if insulated beneath to keep the heat to the floor above. If there is enough exposed floor space to give off enough heat to compensate for the amount of heat lost from the room, it will work.

First, you need to perform an accurate heat loss estimate of the room. You can do this for free at http://www.hydronic.net

Then multiply the exposed square feet of floor space by thirty and you will come close to seeing if it can be done.

You probably can not do this sucessfully because the house has cast iron radiators in it. This usually means that the house was built before the concept of insulation came about in the 1950’s. Because kitchens are usually ringed with cabinets and appliances that prevent installing long lengths of baseboard, many installers use a blower heating unit called a kickspace heater. This can be placed under the bottom of the larger cabinet to blow warm air across the floor at foot level. They come in 8000 btuh sizes which handle most kitchens and are included into the hot water heating system.

If you install the kickspace heater, available from plumbing suppliers, it would be best to do as you suggest – to put the device on its own pipes from and to the boiler with a separate circulator as they usually have a high resistance to the flow of water and may rob heat from a loop it is cut into. It will reguire an electrical connection for the blower.

The easist way is to have a plumber install one, as they do this regularly.

[GuestParticipant]

I recently tore out the cast iron radiators from my house and installed a Stadler Pextron radiant heat system in my first floor area. I opted for typical hot water base board for the second floor.
The first floor area had open joists under neath so i used 1/2 tube with radiant aluminum heat transfer plates and r-19 insulation.
i had to break the loops into 5 seperate zones, but used 1 circulator.
Another option is radiant panels using smaller tubes. these panels are machined out of plywood and screw down.

i used the radiant panels in my 2nd floor bathroom because i did not want to tear out my kitchen ceiling.

talk to Eric at Boyertown Supply in boyertown, PA.

[Author]

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