WT*

You tell me?

Comment

You need to be a member of Home Energy Pros to add comments!

Join Home Energy Pros

Comment by Eric Kjelshus on July 15, 2014 at 6:44am

I took 3 HOBO's and put in flue gas B1 pipe very top - mid way - at breaching ( in basement)  with a over sized 80% my house before change out but after sealing and high R was done, when from R-13 attic to R49 and sealed all holes walls from r-6 to R-20 and sealed with new windows.  went from 97,000 BTU to 34,000 BTUs/hr at 0'  I took the stat at 1' droop  and put a 5 gal bucket  under the hoz run.  At top of flue pipe never got to 250' and stayed  wet the whole time.  I rotted the flue/furnace/ in 4 mo.   You have to dry out the flue each hour to keep the pipe from just coming apart and fall down.  If you keep flue gas ( in my case) above 265'  with both hot water heater and furnace  above 265' will dry out the flue and will last very very long time.  I do my best to keep the flue gas temp as high as I can, Its the heat that's keeps the flue gas up the flue and out of the building,  unless you use a power vent  or PVC flue pipe.   

Comment by Bob Blanchette on July 14, 2014 at 7:40pm

+1 if flue gasses are too cool it will simply rot the pipe out. That's a big reason that double wall pipe (b vent) is used even when it's not required by code for low clearance.

Comment by Eric Kjelshus on May 28, 2014 at 7:07pm

I saw this a lot in the 60-70'.   not so much with 95% furnaces.   This will drop the flue temp some 100'  then the flue will condensate - stays wet then it just rots  outside in.   For fun turn the stat up to 85'  then use the IR photo to see heat loss.    Then look at temp at top of flue if under dew point then drip.  This will just rot the boiler/furnace/hot water and flue pipe

Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.

Latest Activity

Walter Ahlgrim replied to James White's discussion What happened to Home Energy Pro's website?
"Try downloading Google Chrome web browser https://www.google.com/chrome/browser/ I had similar…"
4 hours ago
Stacy Hunt posted an event

Building America Webinar: Multifamily Ventilation Strategies and Compartmentalization Requirements at Virtual

September 24, 2014 from 3pm to 4:30pm
The Building America Program is hosting a no-cost, webinar-based training on Multifamily…See More
5 hours ago
Ben Jacobs replied to Bud Poll's discussion Another benefit from air sealing
"This is info I give to clients that I serve. People who live in homes that are not energy efficient…"
7 hours ago
Brennan Less replied to Bud Poll's discussion Another benefit from air sealing
"Thanks Bud. I just feel the need to point out any such issues, because we as a field need to be…"
10 hours ago
Bud Poll replied to Bud Poll's discussion Another benefit from air sealing
"Hi Brennan, "weak and irrational" is not at all what I was trying to communicate. …"
11 hours ago
Christopher Talarico replied to Christopher Talarico's discussion Heating with Tankless Water Heater & Hydronic Air Handler vs. Gas Furnace
"Barbara, thanks for the info - this is some of the research I was interested in seeing. That report…"
11 hours ago
Brennan Less replied to Bud Poll's discussion Another benefit from air sealing
"I would love to see such matters discussed on this forum without broadly characterizing women as…"
11 hours ago
Eric Kjelshus commented on Christopher Morin's blog post Top 5 Changes to ACCA Manual S
"I run loads each day.  BUT my completion does not,    I see so much over sizing…"
11 hours ago

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service