OWB backup...........brainstorming needed

[Richard@PM]

Ok here we go, you have radiant with no indoor boiler,first get a good cold start boiler ( I like the Biasi direct vent ), replumb the lines from the wood boiler through a plate exchanger ( with counter current flow for best heat exchange ) on the incoming wood boiler side place a honeywell strap on aquastat to the copper or black iron piping ( pex will not work well ), use the r and b terminals to interupt the power to the b-1 terminal wire that fires the oil burner, set the strap on aquastat at about 160 degrees, any time that the water temp coming in from the wood boiler is above 160 degrees the oil boiler cannot fire, below 160 the oil boiler will fire on any call for heat and it will run up to its setpoint of 185 degrees, now you will have two sources of heat protecting both wood boiler water temps and home heat. Next lets look at the oil boiler side, this should be piped in a primary secondary manner so that the oil burner is not heated by the wood boiler when it is not needed, only the primary loop that supplies your radiant will be heated at this point and your radiant loops draw from it, the oil boiler then injects into that loop only when needed. When piping this primary loop you should install two more tees and ball valves for any future alternative heat sources or extra loads and just cap them off. If this sounds like something that you are interested in getting involved you may PM me and I can explain in more detail over the phone. I still type with one finger and have not yet figured out how to post photos from my phone on here, perhaps someone could help me with that part and I can post a diagram of this setup.

 

[mtfallsmikey]

Ok here we go, you have radiant with no indoor boiler,first get a good cold start boiler ( I like the Biasi direct vent ), replumb the lines from the wood boiler through a plate exchanger ( with counter current flow for best heat exchange ) on the incoming wood boiler side place a honeywell strap on aquastat to the copper or black iron piping ( pex will not work well ), use the r and b terminals to interupt the power to the b-1 terminal wire that fires the oil burner, set the strap on aquastat at about 160 degrees, any time that the water temp coming in from the wood boiler is above 160 degrees the oil boiler cannot fire, below 160 the oil boiler will fire on any call for heat and it will run up to its setpoint of 185 degrees, now you will have two sources of heat protecting both wood boiler water temps and home heat. Next lets look at the oil boiler side, this should be piped in a primary secondary manner so that the oil burner is not heated by the wood boiler when it is not needed, only the primary loop that supplies your radiant will be heated at this point and your radiant loops draw from it, the oil boiler then injects into that loop only when needed. When piping this primary loop you should install two more tees and ball valves for any future alternative heat sources or extra loads and just cap them off. If this sounds like something that you are interested in getting involved you may PM me and I can explain in more detail over the phone. I still type with one finger and have not yet figured out how to post photos from my phone on here, perhaps someone could help me with that part and I can post a diagram of this setup.

Biasi is a good boiler, altho he may not have local sales/service support...I sold Burnham for many years.

 

[Richard@PM]

Biasi is a good boiler, altho he may not have local sales/service support...I sold Burnham for many years.

Biasi happens to be my choice in cold start boilers and is one of the larger companies here in the northeast, to me the manufacturer is not the more important issue, cold start is and if it were me, it would be direct vent to save the existing flue for future back up wood stove inside for possible extended power outages.

 

[war-wagon]

Biasi happens to be my choice in cold start boilers and is one of the larger companies here in the northeast, to me the manufacturer is not the more important issue, cold start is and if it were me, it would be direct vent to save the existing flue for future back up wood stove inside for possible extended power outages.

Richard,

thanks for all of your help and i will be contacting you in the future. few more questions though. what size furnace should i be looking at (5000 sq ft). also the two manifolds are roughly 60' apart, wondering it that would mean two furnaces, each would heat roughly 2500 sq ft in that case. thank you for your feedback

 

[Richard@PM]

Richard,

thanks for all of your help and i will be contacting you in the future. few more questions though. what size furnace should i be looking at (5000 sq ft). also the two manifolds are roughly 60' apart, wondering it that would mean two furnaces, each would heat roughly 2500 sq ft in that case. thank you for your feedback

The size of the boiler is up in the air unless a real heat loss annalisis is done but guessing I would say around 180,000 btu,no you would not need two boilers if you plumb with primary secondary piping, the circ on the primary loop would feed all zones and you would get some residual heat off the primary piping, you may wish to insulate it.