MA Gas PVC Venting Code

camiarrobino

Hello -

Does anyone happen to know what MA code is for the maximum allowable distance for PVC venting for high efficiency gas equipment? We have an oil warm-air furnace, which works fine, that's in the middle of the basement since that's where the chimney is. At this time with the oil furnace working fine & being 10 years old, the only way I'd entertain a gas furnace (we do have gas in the house already) , is if the gas furnace can be plopped right smack where the oil furnace is, so that we can use the existing ductwork. If we have to start getting into replacing the ductwork, I don't think I'll be able to justify the cost at this time. The entire basement is about 28x28' so we're talking max of maybe 15' ish to the nearest exterior wall

Mad Dog_2

The Manufacturer usually dictates that . Mad Dog 🐕 

EBEBRATT-Ed

@camiarrobino

As @mad dog pointed out you have to follow the venting instructions that come with the new furnace. PVC is no longer allowed you have to use what the furnace mfg recommends. Probably polypropylene.

The vent length you need seems well within what can be done with almost all furnaces.

Basically the MA. code defers to the MFG instructions with high efficiency equipment

PRR

My furnace exhaust runs 4 feet up, 11 feet over to the wall/rim, 5 feet up and 2 feet out (to clear snow). Three 90 elbows and a 45 elbow. This is well within my burner's specs. My size was (in 2012) rated to blow 65 feet of 2" plastic pipe, minus deductions for elbows. It looks like all BTU sizes, the smoke blower is scaled to give 60' 90' and 150' solutions in 2" 3" or 4" pipe. 2" pipe is easy to route, 4" could be tougher (but could put my smoke on my neighbor's property ).



I think these things all expected to get set in the center of the cellar (cuz chimney and pipes or ducts) but routed out to the sidewall (cuz chimney regulations keep getting tighter).

EdTheHeaterMan

A 10 year old oil furnace is nowhere ready to be replaced unless you have neglected to maintain it properly.

If Natural gas is consistently lower in cost per BTU per dollar spent, then I might consider changing the furnace to gas at 15 years old. but you have plenty of life left in your furnace.

That said, 15 ft to the outside should be no problem for most condensing furnaces unless there are lots of turns. Each elbow may add over 5 ft of equivalent length

camiarrobino

EdTheHeaterMan said:

A 10 year old oil furnace is nowhere ready to be replaced unless you have neglected to maintain it properly.

If Natural gas is consistently lower in cost per BTU per dollar spent, then I might consider changing the furnace to gas at 15 years old. but you have plenty of life left in your furnace.

That said, 15 ft to the outside should be no problem for most condensing furnaces unless there are lots of turns. Each elbow may add over 5 ft of equivalent length

Yes you are (hopefully) right that the oil furnace has plenty of life left. I probably won't end up doing anything until the time comes to replace or repair something major on the oil furnace. Yes, gas is cheaper for sure on a BTU basis in our area - gas is about $1.33 per therm (100k btu) and oil has been about $3.5-4.00 per gallon, and in fact a bunch of the ripoff oil companies near me have been a lot higher than that (138k btu)