I saw your site for the first time tonight and thought you might be able to offer some advice.
I am ever so slowly modifying our existing home. We currently have a “woodchuck” which is a wood burner with forced air. The system is installed in our basement. Although it heats much better than our heat pump, I would prefer radiant type heat over forced air. Also, most of the radiant heat from the unit is lost to the dark corner of the basement.
What I would like to do is install a traditional wood stove on our main floor to use as our primary heat. Here is my big question- Is there a way to enjoy a traditional wood stove and use that stove to heat water for a subfloor radiant heat system or even wall mounted radiator for hard to reach bedrooms and bathrooms???
I have seen someone install an old beer keg at a 45 degree angle, suspend about 6 inches above a wood stove. They had brought their water supply into the keg and preheated their water before it got to their hot water heater. This significantly reduced their electric bill.
I guess I’m looking for something similar and code friendly of course….
Thanks for your time,
Polk County, NC
Although most heating of buildings and homes before the advent of central air conditioning systems was hot water or steam radiators. Now things are changing again and many up-scale homes are starting to utilize hydronic heating due to the higher energy savings and comfort. Our 3 story solar home has a built-in masonry fireplace in our ground level (partly below grade) family room. This fireplace has a Hydro-Heater hydronic firebox which is “hollow” on all 3 sides and the bottom which allows water to flow around these areas then this water flows up into a heat exchanger containing 90 feet of boiler tubing. This heated water is then pumped into a air heat exchanger located in the discharge side of my central air handling unit, which circulates this heated air to every room of our home including all 3 floors. When we have a roaring fire in this fireplace, every room of our home stays at the same temperature and there are no cold spots.
I have also designed many systems like this for others only we piped the heated water to baseboard hot water radiation located in each room, and used motorized zone valves to allow each room wall thermostat to separately control the temperature of each room. Although most of the wood-forced boilers you will find advertised these days usually are the self-contained type that is located outside and piped into the home, there are still several manufacturers that offer “hydronic inserts” that look like a log holder that you place inside a standard fireplace. Many wood stove manufacturers offer an optional hot water coil feature, but these are usually intended to only heat a domestic hot water tank and not the entire house.
Yes, you can heat a radiant floor, but the problem is most radiant floor heating systems keep the water temperature in the lower 100 to 120 degree range, and most hydronic wood stoves can easily produce hot water in the higher 160 to 180 degree range which is much better suited for a baseboard radiation system. This means a radiant floor system will require a storage tank with one small pump circulating tank water through the hydronic fireplace to heat the tank, and a second small pump to circulate heated tank water at a different flow rate through the radiant floor piping. Remember, boiler water or water passing through hot water radiators and radiant floor piping usually will include additives to reduce sludge and rust, and you cannot mix with your domestic hot water system (sinks and baths), so if you want to also heat your domestic hot water tank, you will need a separate coil in this storage tank for that piping.
You are on the right track, but remember, these are classified as a “boiler” and if you don’t include the proper pressure and temperature safety relief valves in your piping, these things can blow up and do some real damage. Also, manufactured hydronic stoves are made from “boiler grade” steel which is much stronger with no flaws or weak spots. This may be why there are not as many manufacturers these days and why I do not agree with your “beer keg” idea!