Seems pretty elementary doesn't it?  What should be a simple safety check on fossil fuel burning appliances, particularly for boilers with regards to ease of inspection, often is assumed with complacency or even goes unchecked.  I know everyone's maintenance schedule is packing up in the Northeast with the cold snap this week, so Technicians Take Heed!

There are many indicators that should trigger the phrase: "Check the flue!"  I always measure the draft in the flue of a natural draft, 80% appliance.   Too high or too low of a draft both can be an issue.  HVAC Contractors tend to focus on the 'too little draft' by installing chimney liners, completing Combustion Appliance Zone and CO testing.  Of course this condition could be the most dangerous, so I can't blame them.  Who ever expects to pull the flue off the boiler, look into the chimney and see what is pictured?  There must have been 40 years of garbage piled up!  Really is a spectacular thing that after all the years of maintenance I have yet  to become complacent with the Flue. 

Did you know the draft of the chimney is very dependent on the temperature difference between the flue gas and outside.  The greater the temperature difference, the better the draft (generally speaking).  This means the draft may be just fine on a cold WInter night, yet spill gases on a warm Fall afternoon.  Conversion warning: 25 Pascals = .10" w.c.  I know: metric, really?...Trust me, the rest of the world has the real gripe when they see standard measurements.  I bet your electronic manometers or even magnahelics (whatever you are using for draft measurements) have this scale.  Take a look at this chart supplied by Building Performance Institute (T_Out is your Outdoor Ambient Temp), start testing, and be sure that boiler will be safe all year long.  Oh, and don't forget about the water heater too!

 

 

BPI.org

The draft was just fine on this older, larger than most boilers (-.03"w.c.).  Except how long before that chimney became a real problem?  I have to tell everyone: I have found birds, nests, even a squirrel in a 90%+ flue.  Yes, that was a rotting mess to cut through with a hacksaw in a half-finished basement.  Always test the draft, measure the CO, and look into the flue/chimney.  You may just be surprised one day; possibly save someone, or maybe a home!

http://excessair.blogspot.com/2013/09/check-flue.html

Views: 830

Comment

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

Join Home Energy Pros

Comment by Bob Blanchette on October 8, 2013 at 4:46pm

ALL dryers should have the duct checked annually. Electric dryers will set the lint on fire if the heating element doesn't burn out first.

Comment by Dennis Heidner on October 8, 2013 at 3:23pm

Good article..

If the homes have a natural gas dryer - check the flue -- in this case the vent line is as important.  Long drying times are symptons of a clogged dryer vent... and when its natural gas -- that means the flue is not operating efficiently.  

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

Mst. Fatema Aktar is now a member of Home Energy Pros
8 hours ago
Robert Leone added a discussion to the group Energy Auditing Equipment for Sale, Trade or to Purchase
Thumbnail

Blower Door Package for Sale

Hi,I am selling my blower door with extras as a package or individually. These items are used but…See More
14 hours ago
Profile IconRobert Leone and Richard Vito joined allen p tanner's group
Thumbnail

Energy Auditing Equipment for Sale, Trade or to Purchase

Discuss the pros and cons of the equipment you are interested in prior to purchase. Post equipment…See More
15 hours ago
Richard Vito joined Sean Lintow Sr's group
Thumbnail

Best Practices (Residential)

Best Building, Retrofitting, or even Auditing Practices - what are they, what should change, what…See More
22 hours ago
Richard Vito joined James Sayers's group
Thumbnail

Marketing Energy Efficiency

Sharing ideas, tools and examples of promoting energy efficiency to consumersSee More
23 hours ago
Richard Vito joined Allison A. Bailes III's group
Thumbnail

HVAC

HVAC design, Manuals J, S, T, & D, Duct leakage, Air flow, ENERGY STAR new home requirements,…See More
23 hours ago
Richard Vito joined Kyle Brown's group
Thumbnail

Wrightsoft - Manual J / Manual D

If you use Wrightsoft to calculate loads or design ducts, you likely have questions.  Get answers…See More
23 hours ago
Jim Gunshinan commented on Jim Gunshinan's blog post Energy Upgrade California—Up Close and Personal
"I had a revelation while attending Bruce Manclark's session of duct leak testing at the Energy…"
yesterday
George J. Nesbitt commented on Jim Gunshinan's blog post Energy Upgrade California—Up Close and Personal
"Blower Door; the 2007 test was a depressurization test, and the 2014 a pressurization test, which…"
yesterday
George J. Nesbitt replied to Kaushal Bharath Raju's discussion Affordability & Deep Energy Upgrade/Passive House Retrofit in Berkeley, California.
"Plan, plan, plan, plan. The 1st step to is to understand the house, how it's built, the…"
yesterday
George J. Nesbitt posted an event

High Performance Windows - A Panel of Experts at Pyramid Alehouse`

April 26, 2014 from 3pm to 5pm
Join a lively panel discussion on high performance windows. We'll cover some basics, as well as…See More
yesterday
Kaushal Bharath Raju replied to Kaushal Bharath Raju's discussion Affordability & Deep Energy Upgrade/Passive House Retrofit in Berkeley, California.
"Hi David, Thanks for pointing out Martin Holiday's article. I do not wish to engage in the…"
yesterday

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service