A Couple Simple Questions About Vacuum & Pressure, 52i

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

Randy Fischer

Member
Dec 3, 2014
84
Purcellville Va
Searched past forums for this question, but did not see much in the way of a simplified explanation. Trying to learn how my Harman 52i works. Quite a lot of discussion on here about bad vacuum switches and clogged vacuum lines and such. As I understand it (and I don't fully), there is a fan unit that sucks air from the outside air vent, and blows it (with some force) through the holes in the burn pot to create a blast furnace burn area for the pellets. That same positive pressure in the fire box forces the waste gases out the exhaust vent. I could see where there could be a small positive pressue in the fire box if the air coming in is slightly greater than the air going out. Do I have this right? Is this what the vacuum switch is measuring? Does it follow then that a higher pressue reading (assuming you have a guage to measure it) would mean trouble, as in a clogged vent? Lower reading means a leaker gasket somewhere?

Where does the need for a vacuum hose come in? Does mine even have one?

Sorry for the fundamental questions, but you gotta learn the basics first!
 
Randy, the Harman website has alot of informational videos, copies of manuals, videos on how to clean your insert ...

Read your manual, there is a thread on the pellet mill main page about what your manual doesn't tell you. As to the basic concepts of how pellet stoves work - google. I think firebox is a negative WC reading...

http://www.harmanstoves.com/Owner-Resources/Use-and-Care-Videos/Accentra-52i-Pellet-Insert.aspx
Thanks, have done most of what you suggest, good stuff. Your last comment is what confuses me. How to you blow air in (and through) the firebox (positve pressure) and at the same time suck air out (negative pressure)?
 
The exhaust fan blows exhaust out the vent. The negative pressure caused by the fan is what pulls air in through the intake.
 
  • Like
Reactions: Lake Girl
Firebox is under a vacuum as is almost all of the stove till it exits the stove. Air blowing into the firepot is really air being pulled into it. There is a positive pressure pot stove out there with a natural draft venting but we won't try and start any more confusion:)
 
Firebox is under a vacuum as is almost all of the stove till it exits the stove. Air blowing into the firepot is really air being pulled into it. There is a positive pressure pot stove out there with a natural draft venting but we won't try and start any more confusion:)
Thanks folks, I misunderstood, thought the combustion blower was pushing air in, it's really sucking air through and out exhaust. Got it!
 
Status
Not open for further replies.