Another OAK question

[lawman349]

Hey guys- newbie question:

I just bought a Savannah Saranac pellet insert. The installation instructions call for a 2.5" vent for "combustion air intake."

My masonry fireplace has a 2.5" tubular vent to the outside through the back wall of the fireplace that terminates at a louvered cover. Do I actually need to connect the vent tube in the masonry to the "combustion air intake" on the insert with a flexible vent style tube?

...or can I simply ensure the vent in the masonry is open and install the insert without actually connecting the two? It seems like the insert would pull plenty of outside air through the masonry vent without actually connecting the two.

Your thoughts?

 

[SmokeyTheBear]

Connect the two and make certain that the lovered cover is open.

Not that I'd rule out just sitting it into the fireplace, just that I'm not so sure that all of the air it was slurping in if you did that would be just unheated outside air, if you get my drift.

There is one other thing that could happen but with a good vertical run in the masonary chimney it isn't likely.

But for the sake of completeness and other considerations (such as other air suckers in the house) it is also possible that smoke could exit the air intake under certain conditions.

Thus it is best to connect the two, it is simple, the job of cutting through things has already been done, and there are really no downsides.

 

[Snowy Rivers]

I agree 100%

Having a good solid connection (or flexible) is the best to assure a completely satisfactory setup.

With your chimney I would run a flex pipe all the way to the top and cap the masonary chimney so you dont have any worries about getting smoke into the house through the convection fan.

The incidence of smoke coming out the air inlet is rare but can occur during a power outage or sometimes after the stove has been shut down and a lone pellet falls into a firepot that is still quite hot. The pellet sits and smolders and without the exhaust fan running the smoke can back up..


Snowy

 

[vvvv]

Open pipe to outdoor provides cold air & possible spot for condensation? I wouldn't worry about a liner for the chimney but if you decide to install 1 make sure to read the specs for the stove which say that the longer the liner-the bigger the liner needed. My pstove has an OAK which I readily remove if I want interior venting or not & when i disconnect the OAK from the stove I simply place the end of the hose on the floor so it blocks the airflow from outdoor.

 

[SmokeyTheBear]

His stove will be fine with a vertical liner run of up to 20 feet with 3" pipe. This will make his total EVL approximately 15.

Above that I'd switch to 4".

Just so you know BLIMP his insert is the same as my FS, just a different casing.

He will have more issues if his OAK (or his air intake pipe) is even partially blocked than if his vent is a little too long.

His primary condensation issue will be be confined to the interior of the fireplace and given the heat on the inside of the shell on my stove not likely to happen above an outside temperature of 0 in the winter. My OAK doesn't start having problems until the outside air temperature drops into the single digits and then the issue is on the outside of the OAK.

In the summer your OAK should be blocked and even if you don't have an OAK the air intake should be blocked if the room the stove is in gets muggy in the summer.

Blocking the air intake and applying a little light oil coat to the burn pot receptical and firebox surfaces will prevent the rusting that can occur in a damp environment.

 

[lawman349]

Thanks for all the replys guys! I can't wait to get this insert installed - I pick it up tomarrow. Probably going to do the install next week. Its too bad it was 68 degrees here yesterday.

Smokey- do you have your chimney completely lined? I was considering using a block plate at the flue and running a 3-5 foot rise above that into the chimney. Is this a good idea or will I have draft or other problems?

 

[SmokeyTheBear]

Thanks for all the replys guys! I can't wait to get this insert installed - I pick it up tomarrow. Probably going to do the install next week. Its too bad it was 68 degrees here yesterday.

Smokey- do you have your chimney completely lined? I was considering using a block plate at the flue and running a 3-5 foot rise above that into the chimney. Is this a good idea or will I have draft or other problems?

I have the freestanding version so I don't vent up a chimney.

You shouldn't have any issues doing a block plate and going up several feet above that, however that method can overtime become a cleaning nightmare. It is better to go all the way up the chimney and put a plate there so you can clean everything out and not have crud being pushed out of the venting and onto the block plate. Overtime you can build up a good pile of crud above that plate.

Different strokes for different folks I choose to get the cleaning done at one time and don't want surprises if I ever revert back to the fireplace.

Whatever you do make certain it is to code.

ETA: If you respond and I don't answer it is likely I'm rebuilding my system. Seems that for some reason the auto install messes up with my split disk drive environment.

 

[lawman349]

Thanks! I am probably going to install the full length flex pipe later and cut costs for now. I am going to connect the outside air intake to the vent in the masonry.

I really appreciate y'alls help.