Baseboards fed by fireplace? (how much, fireplaces, water tank, tanks)

[retrogal214]

We are looking at putting a contract on a home with fireplaces that heat the baseboards. How does this work exactly? The house is on propane and they said to save money during the winter this is the best method.

Anyone have any experience with this? How well does it work?

Thanks

[chet everett]

Seems highly unusual. I would be curious to see their propane usage and get some idea of how much wood they typically burn.

There are folks that do run closed combustion heating plants fueled by wood but in a fireplace any air you use for combustion is comming from the house which means both the heat you paid for is going up the chimmeny and that air leaks are actually encouraged...

[MrRational]

Originally Posted by retrogal214

We are looking at putting a contract on a home with fireplaces that heat the baseboards.
How does this work exactly?

No idea. I've never heard of such a thing.

Baseboards are "hydronic" which means water is pumped through them.
Water that is heated in a boiler (usually in the basement).

The house is on propane...

Boiler? Water heater? Stove?

You need to do some more homework.
Maybe post a few clear pictures too.

[thecoalman]

Is there pumps on this system? Is it connected to the propane system and used as supplementary heat? You need a substantial amount of surface area being heated in a hydronic system to accomplish anything with one small exception.

Other than a full boiler typically with solid fuel anything heating water is a passive system using a thermosiphon loop , a small coil of a few feet goes through the firebox. One end of the coil is connected to the top of the domestic hot water heater or where the PRV valve is (being sure to include the PRV valve in your reconnection). From the drain on the hot water tank there is return to complete the loop. When the water gets hot in this coil it will naturally circulate into the top of the tank and the colder water in the bottom of the tank circulates back into the coil. It's a very slow action but you could heat a tank full of water overnight.

There is some caveats though, the tank needs to be close to and above the stove. Ideally your return from the drain on the tank should be level with the inlet on the coil. I've had people use systems like this to heat really small room like a bathroom with some success but heating a large room is not going to work even if you have a pump because there is not enough surface on the coil to extract enough heat. This is a basic diagram:




This has two tanks but it's not necessary, there is two advantages to it. With a separate tank you're always going to have cold water to heat that wasn't heated with you primary source. You also have a lot of hot water.

[thecoalman]

Originally Posted by MrRational

Baseboards are "hydronic" which means water is pumped through them.
Water that is heated in a boiler (usually in the basement).

Off topic but it depends on the system. A lot of times you can get it to circulate by itself in an emergency situation such as if your pump breaks. On most systems there is going to be a flow valve usually located near the manifold for each zone or boiler in single zones.




If you open that valve on the top the water can flow freely. I accidentally left it open once on a zone for a bedroom and it was 80 degrees in the morning. LOL Boiler has to be below the zone for this to work and if you have a zone that has a lot of elevation changes it becomes less effective. In the case of the bedroom it was just straight shot into a really large radiator and a return.

It's same concept as what I posted previously but the issue with stove or fireplace is the coil is so short you can't make very much hot water.