Enviro M55 "Combustion Intake Flapper" Safety question, other stoves also..

Some time ago I added an OAK which is a straight piece of 4" metal piping out through my chimney with a screened end piece. The stoves standard inlet piece (before I added my section of piping) has a metal flapper on it. When the stove is off, the flapper is closed. When the stove is on the flapper opens inward, the higher the fan speed the wider the flap opens. I know this because I can stand out side my chimney and look directly into the OAK ( with the screen cover removed) and see the flap either open or closed.....

So now I have a power failure, smoke question. Like most insert owners, I probably have abundant natural draft with my exhaust going up and out the chimney (forget my UPS for the moment).....but then I think about that FLAPPER.......and I wonder about other makes of stoves. Do they have flappers on their combustion inlet? I ask because of my perceived safety understanding of an OAK. Isn't an OAK an extra way to vent smoke out of a stove....besides the stoves exhaust venting? If yes, then my flapper should be removed because it only opens inward........yes? no?

If my power goes out, the natural draft of my chimney should draw out all the smoke.
If I remove the flapper does my OAK now also act as an additional escape route for the smoke? Or....
could the added venting actually help increase the natural draft in my chimney? Why even have the flapper?

Thanks, Bill

 

Heat rises and should continue going that route until the path of least resistance prevails. Only one way to find out is to try it. You have to consider outside temps & wind which could play a role.

 

In general, No. Smoke should be pulled upward through stove & exhaust pipe. Inlet air is generally lower in the rear of the stove, so smoke won't go that way. Removing the flapper probably won't change anything.

The engineers at Enviro must have had a reason for the flapper. I'd leave well enough alone.

 

OK do not know that stove,but a lot of pellet stoves have the flapper.It helps keep cold air out when not running.But as far as perfect keeping smoke out of the house,will not happen.Had it happen to me this fall,strong wind,power went out,flue and intake on same side of house,had fumes/smell inside of house,it happenes.But do not take it out as sometimes it is calabrated in to the startup of the stove.

 

Thanks all! I could see where the flapper could regulate incoming air during start-up. Also with no flapper, I suppose some real strong gusts of wind blowing into the OAK could cause some havoc. I agree and will leave alone.
Thanks, Bill

 

That 'flapper' is an integral part of stoves combustion system. Think of it as the throttle plates on a carburetor.... all of the combustion air passes thru that inlet thru the OAK.

If you don't regulate the incoming air the burn can get lazy... you need fast moving air. That's why your stove has a combustion fan. That fan supplies the air for combustion and it expels the exhaust gasses out the vent. And that 'flapper' is what automatically regulates the incoming combustion air.

Pellet stoves do not require any natural draft to operate. Both of my two stoves use a simple horizontal vent... but the house will get pretty smoky if the power goes out. Thankfully we haven't had a power outage here in over 25 years.

 

A lot depends on vent configuration, stove make/model & blah, blah, blah! I know for a fact my Harman Accentra is smokeless on a power outage even with no UPS back up! On the other hand, the Fahrenheit hasn't been tested yet so no report card on that one yet. It would be ideal for everyone to have a smokeless set-up but sometimes it's not meant to be for $$, configuration restrictions and stupidity reasons. Just lack of proper maintenance can be the cause. Maybe we should pressure the manufacturers to make a fool proof units

 

Hello
All Harman stoves have a flapper on the intake tube to regulate incoming air to the burn pot. Many Enviro models and other Make stoves have a manual damper rod that must be adjusted by the user. Englander stoves have an air table burned into the chipset to regulate burn air along with the lower 3 buttons

 

Yard out the air inlet rod until the flame is blue and waaaaaaay up off the floor of the pot, then back it off until the flame is active but not "blow torchy"

Lively flame is a good thing

 

Exact same thing I used to do w/ my Astoria. Opened up the air until base of flame was blue and pellets were just starting to "dance" a little in the bottom of the pot.....perfect!

 

In the Harman Accentra-2 FS the intake indeed does have a flapper, but it appears that it is only regulated by the air being pulled through by the combustion fan. There is no mechanical or electrical control integral to itself to control how much it will open, it's a gravity situation, a simple hinge. When I cleaned my purchased as used stove there was quite a bit of "fluff" in that area, I'm unsure if it ever closed up fully for a few good years. I'm betting the previous owners did not have an OAK attached.

In another thread somewhere I stated that I like to think it's there to keep the rats and cockroaches from escaping my house...