I'm looking at building a tornado shelter for my old farm house and I've come up with an idea that I would appreciate some input on. To make this easy to understand (I don't have pictures), let me put it this way;
Visualize a square two story farm house. Off of one side you build a 28' long attached enclosed/insulated walkway. At the end of this you have a 10' x 10' all concrete storm shelter (buried into a bank). Now the question: If I were to put a forced air wood furnace inside the shelter, can I put a 30' run of pipe from the furnace, along the ceiling of the insulated walkway, then into the house? I know there will be circulation issues, but my main question is can I put a big enough fan to push hot air 30'?
I think I can resolve circulation issues, but if I can't push the hot air that far, it's a mute point. The reason I'm toying with this idea is because it's going to cost me almost $2000 to get the old chimney in the farm house safe. It's an old house that isn't very tight that my son lives in. I have an infinite supply of bur oak on the 70 acres so I'd like to burn wood vs the $380 electric bills this winter.
Thanks for any ideas, and if I need to clarify this, please ask!
I have been in some houses that where 50' long with the furnace in the basement at one end , heat was coming out at the other end 40odd feet away.
For what you want to do it is some what different , you not only have the 30 feet from the house but also the house to cross with the ductwork , but I would be willing to try it out , as I am sure it can be done . How much heat you will loose from such a long run I have no clue as to how one can count this .
You might need a fan in the ductwork to help push the air some , aint no big deal . ;)
Use insulated duct work and I don't see were you should have any problems.
Bruce
> but my main question is can I put a big enough fan to push hot air 30'?
Easy, no problem at all. I would think 8" round duct work would do. I would super insulate it though and build a box around the insulation too. Question would be how many CFM needed to heat the house, I have no idea how to calculate that? Going by what 8" blowers cost, maybe 300 cfm would be enough?
Hi there,i think you should be thinking "Hydronic"
Are you going to have your cold air return coming down the tunnel? It might be pretty cold unless you duct it back as well. I grew up with hydronic heating and did not realize the benefits until I built my own house and used scorched air because it was cheaper. (only to install)
sawdust
Here is a link,you should check out,may help....Bert
Hi there,here is a link ya may want to look at...
http://forum.doityourself.com/forumdisplay.php?f=129
My furnace is 25' from main ductwork in a seperate bulding. I would recomend insulated flexible duct with a box and more insulation and definetly a cold air return like others have said. I would keep the doors at each end of the hallway closed and what little heat comes off duct would be enough to keep it warm. Mine works fine but I do have a 3 speed blower on furnace.
bmill, just a thought, make an EASY EASY way to move wood into the bunker - Carrying or wheelbarrowing really gets old fast!
Thanks for the replies. I am going to build a door into the walkway to haul wood in so I don't have to drag it through the house. i do plan on running a cold air return back to "the bunker" along the floor. I'm going to start with a 600cfm fan and adjust as necessary. I'm getting close to starting the project, I'm going to do a bit more homework though. By the posts, I think it's doable. I appreciate the hydronic suggestions, but I'm probably going to stick with "scorched air". If I get this going, I'll post some pictures.
Bmill
One thing to keep in mind if your furnace is going to be in a small room is how to vent the smoke. My wood-fired boiler is in an 8' x 12' room and when I open the door the smoke can be very heavy and fill the room quickly. In your bunker I think you would want a powered exhaust fan that you could turn on before opening the door.
Bill