DIY Home Improvement Forum banner
1 - 20 of 47 Posts

·
Administrator
Joined
·
42,395 Posts
Termination must be a min 2' above anything within 10' of it horizontally. And comply with manufacturers min height requirements.

International Fuel Gas Code has the section your looking for.
 

·
Registered
Joined
·
608 Posts
High efficiency gas furnaces have different venting needs than the old classical gas furnace that required double wall chimney. The high effeciency furnances use PVC pipe for venting, and you need not only a vent out, but a dedicated freash air source (i.e. two pvc pipes). Many of these furnances can vent through a wall. There's certain requirements like it has to be at least 12" off the ground and you can't vent under a deck (you wouldn't want to as the exhaust gas is warm and moist).
 

·
Administrator
Joined
·
42,395 Posts
Ok. Does the furnace gets it combustion air from outside. Or does it use combustion air from the house.

If from the house, its a mechanical vent system.
If from outside its a direct vent system.
 

·
Administrator
Joined
·
42,395 Posts
I don't know, but I only believe there is one pvc pipe and it is on the roof. It has a downfacing "u" at the top and the manual has a figure labeling what looks like it an intake. The City has now chimed in and it says the minimum is 3" if the unit is in the attic, which it is.
AHJ/Authority Having Jurisdiction.

can add additional requirements to any national or international code.
So if the city is saying 3'. Then they probably have a printed version of their code. that you can get a copy of, and show to the HOA. They can not legally force you to violate an International, or local building/safety code.

Although a down facing U is for an intake. Nothing says it isn't the flue pipe, and terminated wrong.

Might want to recheck the piping.
And post a pic of the furnace and its PVC piping.
 

·
Administrator
Joined
·
42,395 Posts
Got better info. It is an exhaust vent and the unit isn't in the attic. Downturn U wasn't required. I was thinking that he had a larger unit. Sorry. 3' only applies to attic installs. While 12" is the minimum, it depends on pitch of roof. Believe roof is steeper than average. Have forwarded pictures to the city so that it can try to determine pitch.
Direct vent has a different requirement then mechanical or natural.
However. if it doesn't have an intake pipe, it is not a direct vent system.
 

·
Registered
Joined
·
1,857 Posts
if you have access to attic take a 2' level and mark top edge at 1'. hold end of level against bottom of rafter/truss cord and measure up at 1' mark that will give you rise/pitch
 

·
Registered
Joined
·
608 Posts
OMG, I now understand what my HVAC installer was saying.

Rather than having PVC pipes sticking out of the building, my HVAC contractor installed this for a terminater:
http://www.garagejournal.com/forum/showthread.php?t=15066

At first I though this thing hanging on the side of my house (over the garage door) was ugly. But now I see compared to the alternative, it's a thing of beauty.
 

·
Hvac Pro
Joined
·
23,688 Posts
Looks to me like the guy used an existing 4 or 5" chimney to run his exhaust pipe thru as a "single pipe" setup. That is legal with some furnaces and not with others. Depends on the brand and model of furnace. It is more efficient to take the combustion air from outside but in a moderate climate probably would not save huge $$. In a COLD climate YES. My concern is that if the wind is strong and blowing into that elbow it can cause pressure tripping problems with the furnace or flame rollout. We always vent ours vertical with no elbows. Any water in the smoke runs straight down anyway so there is no need for that elbow. Ugly setup and the local code will prevail.
 

·
Hvac Pro
Joined
·
23,688 Posts
I have seen those Bayvents and something very similar used with some high efficiency Rheems. Not sure if that is standard with Rheem or their idea of a concentric. I do not like them as the intake is very close to the house and VERY easy to plug with snow and spider webs/leaves and difficult to clean.
 

·
Administrator
Joined
·
42,395 Posts
Shouldn't even have an ell on it.
And the intake should have been ran out the roof also. Then he could have kept it at 18" with no problem.
 
  • Like
Reactions: Klawman

·
Hvac Pro
Joined
·
23,688 Posts
Your problem is not unique. Condos can be very anal about sightlines, drapery or anything that offends their sensibilities that someone wants to change. Not sure what to do other than camouflage it to match the color of the roof or get a lawyer to read the fine print of the purchase agreement/condo rules to see if there is any leeway for changes.
 
1 - 20 of 47 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top