Wood furnace ducting plan

[arro222]

I have a poorly insulated log home built in the late 70's of 1600 sq ft. It is hydronic. I was looking at wood boilers but the expense is rather high to set up (10-$15,000). to the existing baseboard heat. Currently it is 18* outside and with a wood stove in the cellar, the house is at 63* so I'd like to do something about this other than turn on the oil burner all the time when weather gets below freezing. This is with burning 5-6 cords per year and 275 gallons of oil in the same time period.
As an alternative, I then began to look at wood furnaces. If I go wood furnace in the cellar, is there a simple diagram someplace of how to structure the ducting for a wood furnace to heat the house that has none? Correct me if I'm wrong but I'm thinking ducting would be a lot cheaper than setting up piping, valves and dhw tie ins entailed with a wood boiler. Wood furnaces also seem to be half the price of the wood boilers.

 

[maple1]

Furnace manuals usually have some rough guidelines on basic plenum & ducting requirements. Which you would then apply to your specific house layout.

Yes, I would think it would be cheaper than doing a wood boiler.

 

[Medic21]

If you have an existing boiler it would be very easy to hook up an Outdoor Boiler to it. All you would need is a plate exchanger and hook into the existing system.

A Pristine from Crown Royal or a G series from Heatmaster would both be very efficient.

 

[arro222]

If you have an existing boiler it would be very easy to hook up an Outdoor Boiler to it. All you would need is a plate exchanger and hook into the existing system.

A Pristine from Crown Royal or a G series from Heatmaster would both be very efficient.

Could this also be done with an indoor boiler? My current oil fired boiler is 40 years old but it's main duty was to heat hot water all of these years. It has probably seen half of its work load longevity had I heated the house solely with it all the time.

 

[Medic21]

Most definitely, I priced my system both ways with an indoor wood boiler with storage versus an outdoor wood boiler. The cost difference was within $1000 so I moved everything outside. But you could take either one in.

 

[arro222]

Most definitely, I priced my system both ways with an indoor wood boiler with storage versus an outdoor wood boiler. The cost difference was within $1000 so I moved everything outside. But you could take either one in.

Ok thanks
I don't know where this exchanger goes to tie it all in so I have to look it up. I know several years ago Tarm made a boiler that could also fire an oil feed. If I get proactive, I would like to find a wood boiler that does both as replacing my oil fired boiler would be in the $6500 range. Perhaps mitigate some of the sting involving a wood boiler if I can rationalize having to spend $6500 anyway that could go toward a wood/oil combo fired system. This "water storage" thing that some of these need adds great expense.

 

[maple1]

An exchanger is usually used when you need to tie an open unpressurized boiler to a closed pressurized system. Most OWBs are open, most IWBs are closed (pressurized).

Not sure what is on the market these days that I could suggest, for an indoor boiler that would work well without storage. Things have changed over the years. If you do an indoor boiler without storage, you will likely be fighting creosote.

And most all combo boilers that I know of, are a compromise. They do each (wood & oil) 'adequately'. But also don't know if there are any of those on the market anymore.

 

[hhh561]

I have a Longwood furnace that I still use. They have been out of production for about 25 years I would say. they were made as dual fuel furnaces. Either gas or fuel oil. I have the LP model. Used to use the LP as a backup if we were going to be gone. The LP mode was very inefficient. (think big blow torch in a wood stove). Finally put in a high efficiency LP furnace that we still rarely use as we fire the wood furnace when we are here , which is almost all of the time. I do have chminey problems with cresote problems with the wood furnace and sometimes the house gets smoked up. Have tried many remedies orer the last 30 years and have improved the system but still not like it should be.

 

[arro222]

Thanks for the replies.
It seems best to retain the stand alone oil burner and be thinking of a stand alone wood burner of some sort.