Coal Boiler w/ under floor radiant heat using PEX

Re: Coal Boiler w/ under floor radiant heat using PEX

PostBy: Rob R. On: Tue Nov 29, 2016 9:16 pm

There are lots of bad radiant installs out there. Either people do a bad job on the system install, or they don't bother to see if the room can be heated with radiant heat in the first place. A drafty room with lots of glass is a good example of a room that probably needs more btu's than you can put through the floor, at least without making the floor feel like the beach in July. Sometimes the "great room" may need a length of baseboard to assist the radiant in cold weather.

Do your homework first, and that means a heat loss calculation to see what the heat load of each room is.

My neighbor has a ~1600 sq. ft ranch that was build in the 1970's with electric baseboards. He installed pex with aluminum transfer plates in the entire house, and put a zone of baseboard in the breezeway. I think most of his house has laminate flooring, and there is a little bit of carpet. He has been very pleased with the results.

My uncle has an addition on the back of his house that was always chilly. He ended up putting a "quick trak" system down, which is basically a subfloor that has grooves in it for pex tubing. The pex gets run and glued in place, and then the flooring goes over it. He used some sort of hardwood, and the room is very comfortable.
Rob R.
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Coal Size/Type: Lehigh Rice
Other Heating: Dad's 1953 EFM Highboy

Re: Coal Boiler w/ under floor radiant heat using PEX

PostBy: bksaun On: Wed Nov 30, 2016 7:28 am

I've already done it, works fine, stapled some reflective insulation under it to keep the heat in the joist, mine is under my tile bathroom floor. It used to be like walking on a frozen pond, now its so warm you want to lay down on it! Makes it NICCCCE! ... &mode=view

Hybrid Boiler Project boiler#p303299
Stoker Coal Boiler: Hybrid, Gentleman Janitor GJ-6RSU/ EFM 700
Hand Fed Coal Stove: Hitzer 503
Coal Size/Type: Pea Stoker/Bit, Pea or Nut Anthracite
Stove/Furnace Make: Hitzer/ EFM-Gentleman Janitor
Stove/Furnace Model: 503 Insert/ 700/GJ-62

Re: Coal Boiler w/ under floor radiant heat using PEX

PostBy: David... On: Mon Dec 19, 2016 10:17 pm

I had a hand fed coal boiler. One of my zones is staple up radiant heat. I used 3/8 pex held in place by plastic clips. I have 5 loops that are 200' or less. The loops connect to supply and return manifolds I made from copper tees. I use a Taco 008 circulator to move the water. I use a Honeywell non electric thermostatic mixing valve to control the water temperature in the floor loops. My floor thickness is 1.5" of wood. The radiant will only work down to about 20 degrees. I have a hot water coil in my a/c system to make up the difference.
Radiant and coal are made for each other. They both like long run cycles. I stopped using my coal boiler because my back was no longer up to burning 4 tons of coal a winter. Good luck.
Hand Fed Coal Stove: Chubby clone
Coal Size/Type: Nut
Stove/Furnace Make: Penn

Re: Coal Boiler w/ under floor radiant heat using PEX

PostBy: McGiever On: Tue Dec 20, 2016 7:57 am

Welcome David and thanks for stopping by. :)
Do come on back and share some more of your experiences, we like hearing of others adventures with coal heating. :D
Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
Coal Size/Type: PEA / ANTHRACITE
Other Heating: Ground Source Heat Pump
Stove/Furnace Make: Hydro Heat /Mega Tek

Re: Coal Boiler w/ under floor radiant heat using PEX

PostBy: NJJoe On: Tue Dec 20, 2016 9:59 am

epd1088 wrote:My HVAC friend says that coal will burn too hot but I have to believe that it is possible.

Hope your friend is not a professional. I'm not an HVAC guy but even I know heat can be tempered to the desired temperature using a 3 way mixing valve.