Author Topic: Clearance issue.  (Read 2100 times)

Offline scarey8

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Clearance issue.
« on: October 25, 2017, 06:09:32 PM »
Spoke with a friend of mine who installed a propane furnace the other day.  Superior Propane came to inspect and would not drop the tanks as the furnace exhaust and intake were with one foot from a screened in porch.  The furnace exhaust and fresh air did not terminate under the porch but adjacent to it, 8 inches away.  There was no building opening near by the termination as well.   Im not aware of this code clause, anyone aware or been caught by this? 

Offline Admin

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Re: Clearance issue.
« Reply #1 on: October 25, 2017, 06:39:25 PM »
Only Clauses 8.14.10, 9.3.3 and Table 5.2 mention clearances to building openings and they apply to pool heater vents, cylinders and relief devices.  There is no such Code that requires clearance from the furnace exhaust vent to a building opening.  I have challenged inspectors with this information for years, and have yet to hear a reasonable explanation.

Quote
Clause 8.14.8 - A vent shall not terminate
(a) REVOKED BY FS-225-17
(b) less than 7 ft (2.1 m) above a paved sidewalk or a paved driveway that is located on public property;
(c) within 6 ft (1.8 m) of a mechanical air-supply inlet to any building;
(d) above a regulator within 3 ft (900 mm) horizontally of the vertical centreline of the regulator vent outlet to a maximum vertical distance of 15 ft (4.5 m);
(e) except as required by Clause 8.14.8(d), any distance less than that of any gas pressure regulator vent outlet as detailed in Table 5.2;
(f) less than 1 ft (300 mm) above grade level;
(g) within the following distances of a window or door that can be opened in any building, of any nonmechanical air-supply inlet to any building, or of the combustion air inlet of any other appliance:
(i) 6 in (150 mm) for inputs up to and including 10 000 Btuh (3 kW);
(ii) 12 in (300 mm) for inputs from 10 000 Btuh (3 kW) up to and including 100 000 Btuh (30 kW); and
(iii) 3 ft (900 mm) for inputs exceeding 100 000 Btuh (30 kW); and
(h) underneath a veranda, porch, or deck unless
(i) the veranda, porch, or deck is fully open on a minimum of two sides beneath the floor; and
(ii) the distance between the top of the vent termination and the underside of the veranda, porch, or deck is greater than 1 ft (300 mm).

Offline Hgye

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Re: Clearance issue.
« Reply #2 on: October 25, 2017, 09:08:47 PM »
Doesn't 8.14.8.(g) say the clearances?  The furnace manual will say it as well.  What am I missing?

Offline Mmtc79

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Re: Clearance issue.
« Reply #3 on: October 25, 2017, 09:37:10 PM »
First words of superior propane that's your problem there lol I've had run ins with them also if your to code challenge them but from what your saying your good to go

Offline Admin

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Re: Clearance issue.
« Reply #4 on: October 26, 2017, 08:28:14 AM »
Quote
Doesn't 8.14.8.(g) say the clearances?  The furnace manual will say it as well.  What am I missing?

Yes, but nowhere does it say "building opening".  I'm not sure which clause the inspector is using to enforce clearance to a screened porch.  I agree the porch is part of the building and would leave the gas exhaust vent either 12" or 36" away, depending on BTU's, but I don't see where the Code says this is required. 

Offline Porcupinepuffer

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Re: Clearance issue.
« Reply #5 on: October 26, 2017, 01:42:02 PM »
In the Carrier manual, under venting clearances, they show Item A: "Clearance above grade, veranda, porch, deck, balcony, or anticipated snow level". They have it showing 12" clearance.

I assume someone quickly picks up the owners manual and misinterprets this to be a clearance from all directions for what is listed. They see the comma's and think only the above grade is 12" and the rest are separate clearances all around that require 12".

But when you look at the diagram of Item A, they refer to everything mentioned as something that may be below your venting. So it's a minimum height only clearance. Not side to side... That's probably where someone is goofing it up.

Offline NoDIY

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Re: Clearance issue.
« Reply #6 on: October 27, 2017, 12:14:38 PM »
The intent is opening to a building. Windows and doors are easy..

But flue products and natural gas can enter through a hole in a house. Be it a discharge for a sump pump, a porch that is fully screened in, old house  with a hole in foundation.

Some of these ad on porches extend the living space of the home so you can not exhaust withing 12" of those porche opeings. When in doubt just assume its an opening.

Offline Admin

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Re: Clearance issue.
« Reply #7 on: October 27, 2017, 12:45:17 PM »
The screened in porch is debatable.  Remove the screen and now we have a porch.  There would be nothing wrong with venting in the porch area as long as we had our clearance to windows, doors and air supply.  Adding a screen would not necessarily prevent the flue gas from escaping, but there are always things to consider.  Is the front of the porch half wall and half screen?  Can the client install plexiglass in the winter and not realize the issue they have created?  For this reason I would say it's best to treat the screened in porch as part of the building, and avoid venting inside or near it.  Some inspectors would allow it and some would not.  I suspect the Superior Propane inspector was concerned that flue gas or gas may accumulate inside the screened in porch.  We're also dealing with propane which is heavier than natural gas.  So if the bottom half of the screened porch were a wall, I would not want a propane exhaust vent installed in or near that area.