Venting

**11crv** · 10-15-2013, 06:12 PM

Im going to replace my rheem modulating with a new Airease mod. Furnace this weekend. My current setup is single piped with 3"about 20' with a 2" termination through the wall. The venting is short so i can stick with 2" or should i do 3"? I guess my question is is larger better for a short run? Are there pro vs cons for short 3" runs? What would you do?

**martyinlincoln** · 10-15-2013, 06:39 PM

Follow the installation instructions.

**11crv** · 10-15-2013, 07:51 PM

The install manual says i can use something like 100' give or take of 2" or 3". I will use 4 elbows total. Just wondering if one size is better than the other being that i have such a short run.

**second opinion** · 10-15-2013, 08:48 PM

Originally Posted by 11crv

The install manual says i can use something like 100' give or take of 2" or 3". I will use 4 elbows total. Just wondering if one size is better than the other being that i have such a short run.

Smallest for short run

**LibertyTree** · 10-16-2013, 04:31 AM

Who makes Airease?

**11crv** · 10-16-2013, 07:15 AM

Lennox

**kdean1** · 10-16-2013, 09:03 AM

Pardon my bringing it up, but this shouts DIY to me even though it is posted in tech-to-tech. I would expect any technician to know what the OP is asking.

**second opinion** · 10-16-2013, 09:44 AM

Originally Posted by kdean1

Pardon my bringing it up, but this shouts DIY to me even though it is posted in tech-to-tech. I would expect any technician to know what the OP is asking.

I would expect them to know also but not necessarily reality. Reading the instructions and following them is a huge issue with catagory 4 equipment.

**JKopp** · 10-16-2013, 11:49 AM

I found this one yesterday on an estimate to replace the existing furnace. I bet it was like this from day one. Then I am looking at it more, why did the tract guy put duct tape on the connection?

**11crv** · 10-16-2013, 03:40 PM

All I wanted to know is if the furnace will benefit from one size or the other. There is only a 20' length difference between the 2" and 3". I am s tech and help the installers when we get swamped. From a performance stand point which is better or doesn't it matter. I'm just curious.

**JKopp** · 10-16-2013, 04:49 PM

Sorry I ment to post the photo on another thread. Your 2" should be fine. But as you say 3" is ok too. I would run 2" if book says it's ok.

**LibertyTree** · 10-17-2013, 03:41 AM

Originally Posted by JKopp

I found this one yesterday on an estimate to replace the existing furnace. I bet it was like this from day one. Then I am looking at it more, why did the tract guy put duct tape on the connection?

Looks like it was too short and had 1/2 of bite so duct tape was the hack. A mouse ran by and it came loose. That's criminal