High Efficiency Furnace Roof Termination 10 feet from the property line.

[krikstrebor]

I recently had a code official require high efficiency furnace concentric vent terminations at the roof be terminated 10 feet from the property line. He used 2006IMC 501.2.1 #2 as his justification: "501.2.1 Location of exhaust outlets. The termination point of exhaust outlets and ducts discharging to the outdoors shall be located with the following minimum distances: 2. For other product-conveying outlets: 10 feet (3048 mm) from the property lines; 3 feet (914 mm) from exterior walls and roofs; 10 feet (3048 mm) from operable openings into buildings; 10 feet (3048 mm)above adjoining grade." To me this code interpretation seems to have several problems, 1.the item in question is a vent pipe and not an exhaust. 2. Product conveying exhaust is defined by some code amendments to be: Ducting used for conveying solid particulates, such as refuse, dust, fumes, and smoke; liquid particulate matter, such as spray residue, mists, and fogs; vapors, such as vapors from flammable or corrosive liquids; noxious and toxic gases; and air temperatures exceeding 250F. 3. Item 501.2.1 does not indicate which direction a termination must discharge to need the 10 foot clearance (horizontal/vertical). I did more code research and found under 2006IMC 804 direct venting integral vent and mechanical draft systems, the code requires 10' of clearance to a property line with vents using power exhausters. If I understand correctly power exhausters are mechanical fans installed at the top of the stack to provide draft and if I am correct this item does not apply. Next I went to 2006IMC 804.3.5 Vertical terminations and could not find a reference to distance from the property line but did find the following: Where the vent termination is located below an adjacent roof structure, the termination point shall be located at least 3 feet (914 mm) from such structure. Since the IBC does not provide a definition of "adjacent structure" I am not able to determine if that means a structure possibly on a different lot. So I am stuck without definitive language or evidence to support or deny the 10' away requirement. Has anyone had a similar problem and if so what was the determination and what evidence did you use to support it.

 

[tys90]

Assuming these are gas-fired, I believe you will need to follow the International Fuel Gas Code. IFGC 2009 503.8.4 indicates that you can't terminate condensing vents over walkways where water and vapor may cause nuisance or hazard (probably ice or water pooling). Otherwise I don't see any other requirements about property lines. I don't think section 804 of the IMC is applicable for gas-fired equipment. This is just my quick glance at the codes, I haven't ran into this before.

As always, the authority having jurisdiction has the final say and it's up to their interpretation. I'm not sure what the exact definition of Product Conveying Exhaust is but I wouldn't consider a furnace vent to be product conveying.