dryer vent distance from gas meter? - InspectionNews

Mike Huppi · #1 (**permalink**) 05-10-2007, 07:40 PM

What is the exact distance suppose to be for the meter and dryer vent?

Jerry Peck · #2 (**permalink**) 05-10-2007, 08:09 PM

Quote:

Originally Posted by Mike Huppi

What is the exact distance suppose to be for the meter and dryer vent?

There is no "exact" distance, but there is a "minimum" distance - 3 feet.

The dryer vent is a building opening, 3 feet from building openings to regulator.

Bob H., does the 3 feet also apply to the 'gas meter'? I would think not, just to the regulator????

Mike Huppi · #3 (**permalink**) 05-10-2007, 09:01 PM

Thanks Jerry

Bob Harper · #4 (**permalink**) 05-11-2007, 07:56 AM

Several ways to look at this. One could justify this as a "source of ignition" which would be required to be at least 3 ft. away from the meter. You could view the dryer vent as an intake source into the building and require 4ft. However, it is Not a mechanical intake but exhaust so most AHJs would let that slide, esp. with NG. However, with LP, they would be a lot more nervous.

Keep in mind what it is the codes are concerned with. If the diaphragm on the meter ruptures, you would have a vapor cloud of combustible gas so the idea is to keep it away from, a) sources of ignition and b) entering the house.

NG will rise and dissapate while LP will tend not to disperse but remain in an amophous blob for an extended period just waiting for a spark.

The functional arguement about dryers being intakes is when the house is under negative pressure, they certainly can be a source of infiltration. Those that have backdraft dampers, the valve plate is always coated with lint and won't close anyway.

HTH

HTH

Jerry Peck · #5 (**permalink**) 05-11-2007, 01:59 PM

Quote:

Originally Posted by Bob Harper

Keep in mind what it is the codes are concerned with. If the diaphragm on the meter ruptures, you would have a vapor cloud of combustible gas so the idea is to keep it away from, a) sources of ignition and b) entering the house.

In the meter? Or in the regulator?

Both?

Bob Harper · #6 (**permalink**) 05-11-2007, 02:39 PM

Because the regulator vents to the atmosphere, it has the most potential for causing an Ooops! should the diaphragm rupture. The meter has a bellows affair but it is contained inside. Yes, both are clamshells with a gasketed seal. However, should that gasket fail, experience and testing tells us it will usually result in very low nuisance levels of fugitive gas. Still, it could lead to wastage you are paying for just like a running toilet.

FYI, indoor MP regulators must have a vent limiter device that allows a maximum leakage of 1 CFH at 3/4 PSI per ANSI. Otherwise, it must vent to the outdoors. There used to be appliance regulators with an internal bleed that fed back to the pilot flame. I think these may still be in use with commercial and industrial applications. I still see them once in a blue moon in residences.

HTH.
Bob

Jerry Peck · #7 (**permalink**) 05-11-2007, 05:09 PM

I am familiar with the vent limiter because so many (almost all) of the ones I've seen were misused outdoors as 'vent protectors'.

Vent limiters and vent protectors are different, and are for different purposes.

Also, most regulators I've seen installed outdoors (other than the ones installed at the meter by the gas company) were installed incorrectly, with the vent opening not facing down.

David Banks · #8 (**permalink**) 05-11-2007, 05:16 PM

Bob. What does a vent limiter look like. I see a lot of basement gas meters that appear to be not vented. Any Pics?