exhausting furnace threw the wall?

[burlybrute]

Alright, my chimney is getting in pretty rough shape. I am wondering if I can vent my furnace out threw the rim joice, it's a 4" flue on the furnace. If this will work I would use insulated pipe, do not want to run it up the side of my house. I am getting ready to put a roof on my house and want to get rid of the chimney. The budget allows for a roof this year so the furnace will be next year. I don't want to vent it out the wall if it won't vent properly. From the exhaust on the furnace to the rim joice it will be about a 40" rise over a 8' run. Not looking to gas the family with carbon dioxide fumes inside the house.

 

[brewchief]

No it will not vent properly unless it is run up above the roofline.

There are a few non condensing furnaces that are rated to sidewall vent but not very many, a pic or two and brand/model number will determine if it is one that can be safely sidewall vented.

 

[philjafo]

New b-vent can be ran up the chase that the chimney was in, however as of may non-condensing furnaces might not be available. If your planning to replace next year it wouldn't make much sense to put money into a b-vent that wont work with the new furnace.

 

[Jackfre]

Your other option is to "power vent" the furnace. Your sources for PV's are Tjernlund and Field. This will allow a negative pressure (chimney vented) furnace to vent horizontally. I think when you check the prices it will not be agood investment on a soon to be replaced appliance. There are not a lot of good options other than to try to make it through the season until you are ready to replace the furnace. If you keep the old unit, buy good CO detectors and put one in the mechanical room and one on each floor. CO detectors are your best investment right now.

 

[James-W]

If you want to get rid of the chimney, which a lot of people do, then you need to get rid of the reason for having it. I am not a furnace guy, but I really don't think there is an inexpensive way to vent an older furnace out thru a sidewall. Chimneys give you a "draft" as the warm air rises up thru it and it takes the burned gases outside above the roof line. If you vent the furnace out of a sidewall you won't get the proper "draft" and the furnace will probably not work very well. There would also be a danger of getting burned gases in the house which would not be good at all. There may be a way to vent it out of a sidewall, but I seriously doubt it would be cheap.

You are sort of in a bad way here, basically you want to get rid of the chimney. But you can't really get rid of the chimney until you get a different venting system for the old furnace, or unless you get a new furnace that vents out of a sidewall. To make matters worse, you need a new roof more than you need a new furnace.

I hate to say this, but it may be time to talk with your friendly banker and get a loan for a new furnace. I suspect the cost for the interest on the loan would be less money than the cost of trying to vent the old furnace out thru a sidewall. Keep something else in mind here, a new furnace will no doubt be more efficient than the old one so an added plus for the new furnace is that you will save money on your heating bills.