OAK or not?

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I think it is a good idea to do so. When in use it will save some cold drafts from being drawn into the house. I hooked up the OAK on my Napoleon NZ3000 ZC fireplace, it is supposed to "up" the efficiency by not drawing the heated air from your house into the firebox and up the chimney. Still finishing that install as we speak.
 
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Don't have it here. Would be too much a pita to set up. You will get yey's and nay's from both sides. Personal preference, but I suggest doing at time of install, rather than after if that is your intent.
 
Yep.... OAK is as big of a Debate as Ford vs Chevy...

I say OAK. Its gonna keep the Warm air in the house and the cold drafts from seeping in the drafty places of your home.

As Scotty said, it increases efficiency.... Yes.. In Every unit.
 
Definate YES on the OAK. Many reasons, but mainly to keep the warm air inside the house from getting sucked up the flue, which has to be replaced with cold air leaking into the house.
 
life experience- time travel back to the mid 80's- fireplace in late 50's ranch-very pretty real selling point looks wise- fire up and get a small hurricane traveling through house causing the gas heat to kick in and not much gain from fireplace-installed insert ( cheap box store likely china) cut the hurricane down to a small tornado and actually did put heat back into house, no OAK provision, fast forward 2002 -divorce, ended up in a trailer for 7 years first thing was add a stove- OAK was a code requirement- early secondary burn stove - supplied 98% of heat for 1000 sq ft trailer no drafts and trailer was an early 80's built unit ( less than adequate insulation for my climate summer or winter) 09 back in a ranch quick install of a US stove wood furnace( cheap china made do not recommend), it did reduce ng use but did cause a lot of air infiltration-2010 Englander NC30 installed with OAK, no air infiltration ( well not that I can particularly attribute to the NC30) no use of wood furnace. Now take a look at the top conventional furnaces and water heaters all are sealed combustion all use OAK, must be something there eh?
 
Generally, go for the OAK. All the air that goes in the stove to support combustion and out the chimney must to be replaced, or your house will crush like a beer can. Without an OAK the replacement air must come from the outside (like -10 in the winter) that has to be heated. The OAK will also improve the draft in a tight house.
If your stove is a great match for your house (can easily heat the house to like 80 degrees), or using a little more wood don't matter, going without the OAK will provide a source of fresh air for the house whenever the stove is burning.
As OAK install generally ain't a big deal, I'd say put it in and then you can use it or not as you choose.
 
Now this thread is going oddly... where are all the Anti OAKlies?
 
They went off with Annie Oakley?
 
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Now this thread is going oddly... where are all the Anti OAKlies?

Not an AO . . . but I opted to not put one on my stove . . . have had no issues . . . figured I could always put it in easily enough afterwards if needed.
 
I have OAK's on both my stoves and like others I have noticed less drafts but one good advantage of not having an OAK is bringing in that outdoor air through cracks and leaks, it helps refresh the stale unhealthy house air. I can see the benefits of both but chose the OAK because I have a small tight house with other near by appliances that also compete with the stoves for air. Sometimes i like to crack a couple windows on a moderate winter day just for some fresh air.
 
My stove runs great with an OAK. I personally can see no harm other than the couple hundred bucks it cost. If I had a old leaky house I might not do it.
 
Two stoves, no OAKs, no issues. I don't really have any strong feelings either way about them. As a Mechanical Engineer I think I have at least a tenouous grasp on the issue...from both sides. In my case, things like a lot of masonry stood between each of my stoves and a convenient source of outside air..so I opted out (sometimes an OAK installation is fairly straightforward, other times it's not at all so). I'm not sure I'd have put them in even if they'd been easy installations. I've never missed having an OAK on either of my stoves. My home where the Lopi Liberty lives is really fairly tight and very well insulated (totally re-done in 2008), but the stove just doesn't demand so much combustion air as to actually create any sort of discernible air movement in a 2600 ft² 2-story lofted structure. My shop, where my other little stove lives, is open to 2 garages, and so leaks like a sieve anyway. OAK, or don't OAK...entirely up to you (of course) to fulfill your expectations in your particular circumstances. Personally, I really can't get excited about it either way. Rick
 
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Three stoves, no OAK, drafty house, no problems.
 
Three stoves, no OAK, drafty house, no problems.

Hmm, maybe the three stoves are contributing to the draftiness? I remember reading a single stove exhausts around 50 cfm from your home. Your 3 stoves running at the same time is like installing a 150 cfm fan in your window blowing cold air inside. Maybe some outside combustion air would help your situation?
 
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Hmm, maybe the three stoves are contributing to the draftiness?

No, the house is contributing to the draftiness. The doors are contributing to the draftiness. The windows are contributing to the draftiness. The poor insulation in the third section of the house is contributing to the draftiness. All of which do not have cheap solutions attached to them. Starting next year I will begin crossing some of it off the list, but it will be baby steps as each window will cost about $800 to replace and install.

To replace all windows and doors I am looking at about $20,000. ;sick

I remember reading a single stove exhausts around 50 cfm from your home. Your 3 stoves running at the same time is like installing a 150 cfm fan in your window blowing cold air inside. Maybe some outside combustion air would help your situation?

How are the stoves bringing in cold air when they are running?
 
No, the house is contributing to the draftiness. The doors are contributing to the draftiness. The windows are contributing to the draftiness. The poor insulation in the third section of the house is contributing to the draftiness. All of which do not have cheap solutions attached to them. Starting next year I will begin crossing some of it off the list, but it will be baby steps as each window will cost about $800 to replace and install.

To replace all windows and doors I am looking at about $20,000. ;sick




How are the stoves bringing in cold air when they are running?

As Todd said, every CFM of air that goes up each of your chimneys, is replaced by Cold air coming in through your, doors, windows, etc.

If you installed an OAK it would be sealed system and you wouldnt pull the cold air in. It would drastically reduce the "draftiness" if not eliminate it if done to all 3 stoves.

Your using air you already heated for combustion and sending it up the flue and letting cold air infiltrate every crack in your home.
 
Hmm, maybe the three stoves are contributing to the draftiness? I remember reading a single stove exhausts around 50 cfm from your home. Your 3 stoves running at the same time is like installing a 150 cfm fan in your window blowing cold air inside. Maybe some outside combustion air would help your situation?
50 cfm, interesting. That's 374 gal/min (6.8-55 gal drums_g) . Must be at max burn rate? Houses supposedly aveage 1-2 air changes/hour, ~400cuft/min for a 2000sqft home. One 130 cfm bath fan affects my draft without an OAK.
 
Most pellet stoves at a High Burn rate are exhausting 80 CFM.

So 40-50 CFM doesn't sound out of the ordinary for a mid burn rate. Cat stoves on Low may be less, but regardless. What air goes up and out the house? Must come back in from somewhere.

50 cfm, interesting. That's 374 gal/min (6.8-55 gal drums_g) . Must be at max burn rate? Houses supposedly aveage 1-2 air changes/hour, ~400cuft/min for a 2000sqft home. One 130 cfm bath fan affects my draft without an OAK.

Add other air movers like bath fans, hood/range vents, or old furnaces without an intake.... It only amplifies the cold air infiltration/drafts.

Thats why almost all new efficient furnaces are a sealed system. My Trane LP Hot air furnace has a PVC OAK and a PVC exhaust. Very cool exhaust temps... Its an XV-90 and supposed to be Super efficient. But still used thousands in LP to heat this joint.
 
No, the house is contributing to the draftiness. The doors are contributing to the draftiness. The windows are contributing to the draftiness. The poor insulation in the third section of the house is contributing to the draftiness. All of which do not have cheap solutions attached to them. Starting next year I will begin crossing some of it off the list, but it will be baby steps as each window will cost about $800 to replace and install.

To replace all windows and doors I am looking at about $20,000. ;sick



How are the stoves bringing in cold air when they are running?

When the stoves are burning the air they use for combustion is replaced from cold air coming through all those leaky doors and windows. Each stove is like a 50 cfm fan blowing warm room air up your stack, the negative pressure this creates pulls more outside cold air into the house to makeup for it.
 
When the stoves are burning the air they use for combustion is replaced from cold air coming through all those leaky doors and windows. Each stove is like a 50 cfm fan blowing warm room air up your stack, the negative pressure this creates pulls more outside cold air into the house to makeup for it.


Hmm... Well, an OAK ain't happening any time in the near future, that's for sure. Between the stone walls and a lack of basement, it would not be a fun project to tackle.
 
How many of you have punched through 2 feet of masonry to put in an OAK?

I went through 1 layer of brick and 1 layer of concrete block using a hammer drill with a 4" round bit. Didn't take long but it wasn't solid concrete either.
 
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