Uncontrollable heat source

[fudd]

Morning. Has anybody used their skin tank as a heat sink when installing a wood burning stove with a back boiler? We are still having trouble finding a suitable means of safely dumping the heat from our range. Thanks.

Steve P

[larkshall]

Novel Idea, it could work. I'd try it and see, You might have to put a non return valve in the engine to tank fitting. I'm not sure of your setup, but how are you going to get hot water to flow downhill to the tank?.

[MtB]

Morning. Has anybody used their skin tank as a heat sink when installing a wood burning stove with a back boiler? We are still having trouble finding a suitable means of safely dumping the heat from our range. Thanks.

Steve P

 

The main reason not to do this is that circulation through the skin tank will rely on a working pump. A natural convection heat dump is far safer. Your excess heat will only be dumped while the batteries are adequately charged, and you can be certain the fridge (say) won't drain them while you are sleeping and before the next period of engine running.

 

All the same issues as using a radiator for a heat dump, so what's the problem with a radiator?

 

In addition, you'll need a method of making sure the engine coolant does not short-cut through the back boiler when under way.

[fudd]

Hello. My heating engineer ( domestic ) said I need somewhere to dump the heat if it all goes tits up. Normally this would be in the loft and discharge into the water tank. Can't do that on our boat so I'm thinking of ways to feed the excess off in case it boils so to speak, I thought it would be a bit more efficient than a radiator.

[TUGBOAT]

Hi Steve

 

We have a diesel range. in case of overheating we have a blow off valve/safety valve which dumps water through a skin fitting into the cut and therefore releases any build up of preasure. cost's about £10 in plumbers merchants. hope this is of use to you

 

John

[fudd]

Hi Steve

 

We have a diesel range. in case of overheating we have a blow off valve/safety valve which dumps water through a skin fitting into the cut and therefore releases any build up of preasure. cost's about £10 in plumbers merchants. hope this is of use to you

 

Hello John. That's what I'm looking for I think. The only thing is, what if it blows when someone is walking alongside the boat? Not very likely but it could happen. Thanks.

Steve P

John

[Tony Brooks]

Fit it in the stern then, to one side of the fuel tank, or in the bow. You may have top make up angled mounting b lock so it points directly to the front or back. The outlet could go anywhere as long as the pipe is large enough to ensure there is minimal resistance to any steam/water flow down it.

 

The implication of this thread so far is that you are running a sealed system and that I consider a very dangerous game with a solid fuel/wood burning appliance. If it is not sealed then you should have a header tank somewhere high up in the boat. This would allow steam from a boiling stove to escape (given that the connecting pipe is large enough)but it may well make a horrible mess. If it is not sealed then I would have thought that the water/stem would still exit via header tank rather than a relief valve.

 

I await being told I am wrong by our heating experts.

[fudd]

Hello Tony. We haven't connected it up to anything at the moment and won't until we have a 100% safe installation. I'm just trying to achieve the latter by asking the questions. Thanks for the advice.

Steve P

[BlueStringPudding]

My header tank is like a teensy toilet cistern. It has an overflow pipe into the stern bilge so if the water expands it has somewhere to go without spilling into the boat. It also has a cold water refill pipe with a miniature ballcock and valve. So if the water level in the header tank were to drop after heating-overflow-cooling, the system tops itself back up via the header tank.

 

Once a year I put a little extra premixed antifreeze in the header tank, in case the water has become diluted from the automatic top ups. Otherwise it's designed to be maintenance free.

Edited October 18, 2012 by BlueStringPudding

[blackrose]

The implication of this thread so far is that you are running a sealed system and that I consider a very dangerous game with a solid fuel/wood burning appliance. If it is not sealed then you should have a header tank somewhere high up in the boat. This would allow steam from a boiling stove to escape (given that the connecting pipe is large enough)but it may well make a horrible mess. If it is not sealed then I would have thought that the water/stem would still exit via header tank rather than a relief valve.

 

Couldn't you plumb the top of the header tank out of the boat to avoid steam or mess inside the boat?

 

This is the header tank from the backboiler of my stove. (It's now inside a cupboard)

Edited October 18, 2012 by blackrose

[fudd]

My header tank is like a teensy toilet cistern. It has an overflow pipe into the stern bilge so if the water expands it has somewhere to go without spilling into the boat. It also has a cold water refill pipe with a miniature ballcock and valve. So if the water level in the header tank were to drop after heating-overflow-cooling, the system tops itself back up via the header tank.

 

Once a year I put a little extra premixed antifreeze in the header tank, in case the water has become diluted from the automatic top ups. Otherwise it's designed to be maintenance free.

Hello. This still relies on a pump though doesn't it.

Steve P