97% Modulating Multi-position

[ratitka]

First time installing two pipe pvc furnace. Install manual says no more than 30ft for the vent system. Literally impossible to pipe in less than 30ft. Problems if longer? Increase pipe size?

[chuckcrj]

Read the manual.

Give us a model number off the furnace.

[VTP99]

First time installing two pipe pvc furnace. Install manual says no more than 30ft for the vent system. Literally impossible to pipe in less than 30ft. Problems if longer? Increase pipe size?

How many elbows you planning ?

[ratitka]

Luxaire Model # TM9M100C16MP12A

Ive read the manual and like I said I can not make it outside under 30ft

[ch4man]

not familiar with luxaire but im sure you could find another 100mtbu/ 4 ton drive furnace that you can vent farther than that

[DirkRoper]

I believe York makes that furnace. If you check the manual I think you'll find that 30 equivalent feet is the maximum for 2" pipe, but 3" allows about 90' and 4" allows about 150'. Look for a section called "Combustion air/vent pipe sizing" and check the table.

[BaldLoonie]

The I/O manuals aren't online. Seems very short. Is that for 2" or 3"?

A-S/Trane Freedom 95 can go upwards of 200'

[ratitka]

wow I feel dumb, the 30ft is for the combustion air, but still the question exists, i cant reach outside with 30ft. can i go 40ft?

[pacnw]

as was said, reread the manual and make sure that is not the ONLY size and length to vent it in.

most units I have come across have different distances for different size pipe.

[rundawg]

can i go 40ft?

Yes, if you use 3" pipe.

3" can go to 90 feet as DirkRoper said, minus any elbows (termination elbows are included in the 90 feet).

Review the install manual for more details.

[DirkRoper]

The pipe lengths are for each pipe. Using 2" you can have 30 equivalent feet of vent pipe and 30 equivalent feet of combustion air pipe. If you need to go 40 feet, use 3". Like rundawg said, read the manual.
The manual is important for this equipment. Make sure you pay attention to the rules for running the condesate line or you'll probably be back, scratching your head, wondering why you have a pressure switch fault.

[keith w]

Okay, okay, it's been said but: read the manual. On many units there's a separate venting manual. There are LOTS of considerations, besides just length and number of elbows, height off ground, proximity to windows & doors and inside & outside corners, etc. You HAVE to study it closely to get it right the first time. Often the venting is some of the hardest work in designing a condensing boiler install. Do it right the first time.

Sometimes novel solutions are called for: in one case I went straight through a chimney and out the other side, because otherwise it would have been too close to an inside corner of exterior walls. Worked fine.