Question for outside forced air experts

[llidisky]

Hello all. I recently installed a us stove 1600 Ef outdoor wood furnace. It's a forced air. It sits 10 feet from my house and I did a temporary install where I took insulated flex pipe for the hot air duct(10") through my crawl space opening and tied into my main line duct under my house. I then for the temporary part took the 12" cold air return and just have some 12" duct running I to the crawl space and covered then end with window screen to keep critters out. Before it has dipped into the low 20's. I was easily able to keep the house 74-77. Now that it's in the teens and 20's the house is wanting to stay in the high 60's(fine for me. Wife not so much). I have the internal blower settings where it kicks on at 187 and goes off at 120 degrees. My question is if I was to take the cold air return and run it into my attic and tie it into the cold air duct in our ceiling return where it had a real cold air return, do you think it would get me the extra performance needed to combat the colder temps. My house is a single level fairly open floor plan newer spec home 1550 sq feet. Yes I know this isn't how it was suppose to be hooked up from the beginning. But I didn't want to cut holes in my soffet and build boxes to hide the duct if it want going to work for us

 

[stee6043]

I'm not the expert you're looking for but I would tend to think ducting return air from your house as opposed to getting it from outside air would make a tremendous difference in how your unit is performing. You're talking about a 40-50 degree difference in the air temp going into your furnace.

Are you pretty comfortable with the windows/doors/general construction of your house? It seems like a newer home should be a bit tighter than what you're describing. Heating the whole house without cold-air ducting would lead me to believe you're pushing a lot of air out of "somewhere" right now...

 

[llidisky]

Well as of right now I assume that im pushing air into my cold air returns that got to my central electric furnace. I have a vent in my furnace room that goes into my garage and I made a vent under my house The idea there was for a temporary cold air return the air inside the house rises and goes into the central air cold air returns in the ceiling and would escape into my furnace closet and the. Get pulled through the vent I installed in that floor through the cold air duct that is just hanging out in the crawl space. I realize this isn't ideal. But we are looking to build a home in the next few years so I am just trying to save some cash on heating and trying my best to cut the least amount of stuff possible in this house so the wood furnace can come with us to our build. Sorry for punctuation. I'm not the most disciplined in this aspect when typing on my phone

 

[BoilerMan]

What is the temp difference of the air "pulled" from the crawlspace and the air temp measured at a cold air return register in the house? Is the blower in the wood furnace cycling or running steady? As you already know there is a tremendous heatloss with an outside scorched air furnace.

I am not biased when I say use a boiler to heat your new house when its built! Forced hot air (scorched air as we in the trade call it) ain't the way to go. Low temp radiation is the most comfortable and the cheapest to operate long term.

TS

 

[woodsmaster]

Out door forced air is not efficient to begin with, but if I was using one i would add more insulation to your flex duct or build an insulated box around it. That flex duct insulation is pretty thin. Think I would also return the air from in the house, not the crawl space in an enclosed well insulated duct right beside the supply.

 

[Levon742]

I have a 1600 sq foot log home with a 20 foot vaulted ceiling in the living room installed a shelter wood furnace last month and for the first week did just like you pulling fresh air and the house would stay around 75 but the furnace wasn't running long because of the cool air and I'm not yet sure how I want to run the return so for now I just cut a price of 3/4 inch plywood and screwed a 12 inch round take off to it and ran it through my mud room window it is backwoods I know but it made a world of difference