Welcome, Guest. Please login or register.
Did you miss your activation email?

Username: Password:

Author Topic: cfm lower or higher?  (Read 1483 times)

victor6deep

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 393
  • OWF Brand: Burnrite
  • OWF Model: 228
    • View Profile
cfm lower or higher?
« on: April 13, 2014, 08:31:19 AM »
I'm wondering if a fan speed that is higher on a conventional would be better for efficiency or would a slower cfm fan do the same? My stove has 65 cfm Fasco and seems to work good but I noticed when I add my chimney extension it doesn't like it. If I had a bigger fan on the front I think my extension chimney would work better.
Logged

slimjim

  • Full Member
  • ***
  • Offline Offline
  • Posts: 158
  • OWF Brand: Wood Doctor / HeatMaster
  • OWF Model: 14,000. / G 200 and G 400
  • Southern Maine
    • View Profile
    • www.mainlycustom.com
Re: cfm lower or higher?
« Reply #1 on: April 13, 2014, 08:42:50 AM »
I think you are going exactly the wrong direction, the extra stack is increasing the draft and sucking the heat out of the firebox before the water jacket has a chance to absorb it, a barometric damper to break the draft would be a far better investment
Logged
Wood boiler sales, service and installation for the Northeastern USA.

Sprinter

  • Do it right the first time, its cheaper In the long run
  • Global Moderator
  • Sr. Member
  • *****
  • Offline Offline
  • Posts: 474
  • OWF Brand: Indoor Boiler
  • OWF Model: Menominee
  • In the long run
    • View Profile
Re: cfm lower or higher?
« Reply #2 on: April 14, 2014, 11:55:29 AM »
In a perfect world a variable speed fan that was controlled by burn temp would be the ideal application. Providing just enough cfm to reach peak temps.

On indoor boilers that are natural draft like the Varmebaronen flue hieght and size is critical to be able to gasify..to high and it drafts too much and too little and it won't gasify. We will use a manometer to measure draft and in some cases with a fixed chimney a barometric damper can be set up to adjust the draft to the sweet spot , which can change over the season and burn conditions. This is another reason to have a cheap temp gauge in the stack to monitor your stoves operating conditions.
Logged
Michigan Thumber