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We have a three-year old house with a power vent on an oil-fired furnace. The power vent must go (for many reasons) and we must decide on the best alternative venting route. We may be able to run vent pipe up through closets and eventually through the roof at an optimal location but we need to know what code issues are involved. What restrictions apply to joints, bends, clearances, length, etc.?
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GMan, this is a big can of worms. If you really don't have to, I wouldn't. If possible, find an expert in your area to help. Check with manufacturer to see if you CAN vent the furnace without a blower. Check with the city (or county) to find out what codes apply.
Type B vent (double walled) would be what I would use, regardless of the code requirements. This type of vent needs, 2" minimum clearance to any combustibles. Joints are "snap" together and should be taped with a high temp foil tape, keep bends to a minimum. A 90 degree bend is equivalent to 10' straight, 45 - 5'. You'll have to check the manufacturer on sized and length, plan on at least 5" if its over 30 equivalent feet.
*I'm curious as to why you're wanting to get rid of the power venting. I just changed over to power venting from a chimney w/liner that wasn't functioning properly. See the following post: Bob Walker "venting furnaces" 1/27/02 10:19pm!login=true
*GMan: listen to Tim; he's very knowledgeable about this stuff and I have the highest repsect for his advice.Tim: Afetr you stop blushing, a question:"Joints ... should be taped with a high temp foil tape,"Is this a code or manufacturers' requirement, or "just" a good practice that hasn't been recognized by the poobahs?I rarely see the joints taped in my area (and, if you promise not to tell, I've not looked at this issue before!)
*Bob...Tim...Boys... Type b vent is for low flue temperatures and only for gas.Gman...b Listen up...Oil fired flues need all fuel flues that are rated to much higher temperatures.Fire codes today mean call the fire inspector and go over your installation and permitting issues. b Do not do this from this website!near the stream of absolutely wrong advice,ajAs usual, this site is giving out totally wrong advice at times...
*aj,Thanks; that's what I deserve for posting after a day too long.
*Bob,The sealed joints is not a requirement, and on further consideration, thanks to AJ pointing out the low temp rating of type B vent pipe, not the best advice. Type L is the appropriate vent for oil fired appliances. From the IMC, "Oil fired appliances shall be vented in accordance with NFPA 31." Code doesn't not require the joints to be other than "fastened with sheet metal screws, rivets or other approved means". Minimum clearance for a Type L is 18" unless the appliance is specifically labeled for venting with Type L vents, then minimum clearance is 9" (to combustibles).
*Now about the joints... in any flue... regardless... there is a slightly lower pressure in the flues, so the joints mostly leak air safely into the flue not out of it. If it were the reverse then we all would be dead from CO, CO2 and fires.near the stream,ajPeople do not tape flue pipe on a regular basis.