How wood boilers control heat output?

ElderGreen

Other than the size of the fire what controls the temp of the water a wood (tarm) boiler can circulate through the home?

Gordan

Nothing.

But the same is true of any other boiler. It's just that solid fuel boilers can't really throttle down as quickly or as effectively, so it's paramount to give them some way to shed excess heat while they simmer down. Large buffers and dump zones are typically used.

Mark Eatherton

Oxygen suppression...

Take away one side of the required fire triangle, and the flame gets small. This is exactly why most older wood burning stoves are being banned. Too much useless smoke when the dampers close.



A properly designed system would have a matched storage system, and would allow the fire to burn cleanly at full burn and put the energy into the storage tank system. That energy is then harvested as needed.



Like solar, when you need it the most, you get it the least, and vice a versa.... You have to plan your use carefully around its availability.



Wood fired boilers, set up properly and maintained properly CAN be a clean (relatively) source of energy. Set up wrong and operated wrong, they are an environmental disaster.



There are places back east that the pall of smoke is so bad under certain conditions that health alerts are issued for people with lung ailments. That can't be healthy for anyone...



ME

SWEI

temp of the water

Is affected by the rate of water circulation through the boiler.



Separating storage and distribution is not optional IMO with solid fuel boilers.  As Mark pointed out, the boiler needs a large enough tank to hold all the BTUs in a full load of wood, minus some minimum load figure during the burn time on a mild day.

Paul48

Short Answer

The boilers themselves do a terrible job of controlling heat output,but as Mark said, they can be made efficient, properly installed.

ElderGreen

No surprise then he's

a heck of a time with creosote in the venting for the tarm. Literally blocks the venting after a couple months.

SWEI

creosote

Oh my.  This really does need some attention ASAP.

ElderGreen

I'm betting that

because the tarm is having to idle so often, that is creating the creosote.

ElderGreen

So asides from the pressure

relief valve opening, is the circulation system and the buffer tank the only things that can truly control the temperature of the water?

SWEI

heat loss

will remove the heat gained by burning the wood.  The buffer tank just gives you a place to put the heat until you can use it in the house.

Tom_133

Pics

Take a few pics of the system and post them, we can be more helpful and specific that way.