Adding boiler preheat water lines to wood stove?

[tla100]

I have Heatilator WS-22 wood stove in basement. I have an electric mini boiler in basement to run floor heat for garage. The manifolds go to 1" pex oxygen barrier, then travel above stove to boiler 8' away. Stove is main source of heat in small 800 sf house. Works well.

I want to add a "radiator" or 2 in between side panels of stove and plumb to the 1" Pex going to boiler. No sure if I use a coil of soft copper, or black steel pipe with a few U's. I only run boiler at around 105-110, keep 50x32 garage from 57-60 degrees. There is 2" dow board under concrete and garage is well insulated, but want to cut my electric bill down. There is Glycol in system to prevent corrosion.

Any ideas on what to use in stove? I plan on running pump continuously. Thanks.

 

[ziggo_2]

its been done before... id use steel pipe. copper could warp or cause other problems.

Others have done it already on here, id take their advice over mine if i were you...

 

[stihly dan]

There is Glycol in system to prevent corrosion.

That's the first time I herd that.

 

[peakbagger]

make sure that you include a safety relief valve in the loop as bad things happen if you let it boil.

 

[tla100]

There is relief valve on the top side of the boiler. I have been running boiler for 4 years now. If the pump is running continuously I don't think I would have to worry about boiliing. Boiler is at 18 PSI right now.

On the Glycol, from what I was told, keep sludge and scale from building. Acts as antifreeze and raises boiling point.

 

[Marshy]

Soft copper will work fine and will conduct heat a lot better than the black iron pipe. Mother Earth magazine had a DIY article on this exact thing. They even put a thin piece of sheet metal over it to reduce some losses from the coil. I've considered doing this exact same thing to my wood stove and boiler but then I added up the cost of everything and decided I would be better off buying a thermo control wood burner that has 3-4 stainless water coils in the firebox since I want to upgrade my woo burner in the near future...