furnace install

michael cook · 03-08-2007, 10:37 PM

Iwas given a lennox propane furace for my garage it was in the basement of my sons house here are my question!!! 1- can I run double wall pipe straight up thru the ceiling and thru the roof 2- can I just let the hot air escape out of the holes in the box on top of the furnace or should I run duct work garage is 24x32 I can put furnace centered on 32' wall any other advice is appreciated oh also he gave me the regulator that was mounted on the wall do I need another one on the tank I'm using a 100lb tank thanks mike

harleyrider · 03-09-2007, 08:08 AM

You have to have some duct work.....even if its just a very tall plenum with sevral registers in it. As far as the LP goes, you must maintain at least 15" wc in and 11"wc at the manifold.

michael cook · 03-09-2007, 08:21 AM

thanks for the response if I understand right I can put registers in the sheetmetal box on top of furnace it has now 2 round holes just put grills over the holes correct?? also the 11"and 15" you are talking about can you explain a little more do not want to make a mistake!! also what about running the exhaust straight up thru roof thanks mike

coolmen · 03-10-2007, 10:18 PM

what size furnace is this, btu ? double wall bvent (chimny) you run up thru ceiling and out roof . keep a min of 1 " clearance from all combustable material, wood,sheetrock ect,, buy registers, one on each side and one in the front ,place high so its not gonna blow in your face, dont go to small with the registers or the units high limet will cut out. propane preasure feeding the furnace should be at a set preasure. and is allways adjusted and checked at furnace first start up. because the furnace is moved to a new location with a differant propane set up.i would check the system.

michael cook · 03-11-2007, 03:12 AM

thanks for the replies as far as btu's not sure my son has not brought it over yet!!! should I put a collar in the attic to keep insulation away from chimney thanks

michael cook · 03-12-2007, 07:56 PM

Well my son brought the furnace over today not a lennox but a TEMPSTAR 75000 btu my question is this the exhaust coming out is 3" my double wall pipe is 3 3/4" do I need an adapter the 3" part is flush with the furnace casing so the double wall can not drop over it??? and second question is shouldI cut a hole in the ceiling and put plenum in the attic and run flex trunks or just raise it to ceiling heigth and put registers in the plenum thanks mike

elementx440 · 03-13-2007, 01:24 AM

I don't think the garage size would really justify the ceiling registers, maybe for looks, but I don't think it's needed.

michael cook · 03-13-2007, 08:49 PM

well I worked on the install today built a stand out of angle iron to get it up off the floor 25" off floor, install vents in plenum, put a new filter holder on they taped the old one on!!!! wired it up and installed thermstat put chimney thru roof went with 3" double wall,ran copper line outside and mounted regulator on ext wall also welded up brackets to secure furnace to wall earth quake proof( lol ) thanks for the help guys just need a propane tank now !!!thanks agaim mike