hausdok Posted January 27, 2009 Report Share Posted January 27, 2009 Just a question, Did you do the combustion air calculation to ensure there'd be sufficient air for that unit to combust properly? Basically, garage volume has to equal 50 cubic feet per thousand BTU? If not, you're going to have to open a vent to the outside for air, because you can't take it from the house, and that is going to make the whole thing an exercise in futility. ONE TEAM - ONE FIGHT!!! Mike Quote Link to comment Share on other sites More sharing options...
tcfinishing Posted January 27, 2009 Author Report Share Posted January 27, 2009 If I am correct in my calculations the 45,000 btu furnace needs 3000 cubic feet before a vent is required. My garage is 3,758 cubic feet. Quote Link to comment Share on other sites More sharing options...
hausdok Posted January 27, 2009 Report Share Posted January 27, 2009 Looks like 2250 to me, unless the instructions say to add volume for certain installation conditions. Either way, you should be OK. ONE TEAM - ONE FIGHT!!! Mike Quote Link to comment Share on other sites More sharing options...
energy star Posted January 27, 2009 Report Share Posted January 27, 2009 Is that heater in a wood shop? Quote Link to comment Share on other sites More sharing options...
tcfinishing Posted January 27, 2009 Author Report Share Posted January 27, 2009 No it's not a wood shop Quote Link to comment Share on other sites More sharing options...
tcfinishing Posted February 15, 2009 Author Report Share Posted February 15, 2009 I just wanted to say a final thank you to all who responded to my questions. I lowered the unit heater 7" to allow for a proper flue configuration. The unit heater was inspected, by a city building inspector on thursday afternoon and he passed the installation with no problems. Here are some follow up pictures of the final installation: Thanks Craig Slater Click to Enlarge 44.78 KB Click to Enlarge 32.51 KB Click to Enlarge 26.84 KB Click to Enlarge 27.96 KB Quote Link to comment Share on other sites More sharing options...
Terence McCann Posted February 15, 2009 Report Share Posted February 15, 2009 Is your unit heater approved for sidewall venting? Quote Link to comment Share on other sites More sharing options...
tcfinishing Posted February 15, 2009 Author Report Share Posted February 15, 2009 Yes if you look at the previous pictures I sent there is a diagram of horizontal venting from the installation manual. Quote Link to comment Share on other sites More sharing options...
lowdwnsteve Posted August 22, 2011 Report Share Posted August 22, 2011 Old post-- But I'm in a bit of confusion with the venting and clearing of the soffit etc... I've got the Same Mr Heater 45k.. I also ordered the horizontal vent kit.. With reading the instructions, it say's the venting has to be 4' from any soffit and 12" from the wall etc.etc.. I'm basically doing the identical thing as the OP..BUT,, In the pic of the exterior vent being that close to the soffit??.. IS that code????? I wanted to do the same thing, but essentially extend the piping 12" from the edge of soffit... Just want the inspecor to be happy.. any advice before I start cutting through the wall?? Just don't want to get it all done and the Inspector to Red X me... From Olds, Alberta.. TIA Quote Link to comment Share on other sites More sharing options...
Hearthman Posted August 23, 2011 Report Share Posted August 23, 2011 The city inspector doesn't know his job. This should never have been approved. This units vents under positive vent pressure. Therefore, the venting must be listed for use with positive vent pressure, which is either CATIII or IV. The mfrs. horizontal kit contains B-vent and single walled pipe--neither of which are listed for use under positive pressure through UL 1738. Just because a mfr. makes and sells something doesn't automatically approve it for installation. [:-monkeyd Quote Link to comment Share on other sites More sharing options...
orangetang Posted November 21, 2011 Report Share Posted November 21, 2011 I'm installing a similar unit in my garage, and can say that even the local HVAC contractors would still use a c-vent 90 off the unit and adapt it over to b-vent through the thimble and out past the eave. I called the city prior to starting this install and they confirm that as long as the c-vent is no closer than 6" from ceiling, wall, etc. and the b-vent no closer than 1", there is no problem. Unfortunately for my, my eave is almost 3 feet from the wall I'll be venting through, and the unit is over 2 feet wide, so I'm kind of in a bind for the horizontal maximum of 5" plus a 90 and a condensation leg... It seems kind of weird that Mr.Heater placed your gas fitting right up against the exhaust port like that. I bought a Reznor and there seems to be a lot more room for ducting and gas-line to be run. Hearthman, What are you required to run instead of c or b vent if neither are approved? All these heaters have a single wall, 3" or 4" exhaust. Or do you mean, this style of heater in general is not approved for installation? IE: Lennox, Reznor, Big Maxx and a handful of others have been selling unsafe, non-approved, uninstallable heaters to the public. tcfinishing, shouldn't you have some sort of condensation drain or 'drip leg' on your vent? For the record, I have absolutely no training in any form of HVAC, electrical, plumbing, whatever so I really am asking. Quote Link to comment Share on other sites More sharing options...
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