QUESTION ABOUT AN OAK

  • 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.
Similar situation here - I have an unheated crawl - it's well insulated though and it stays @ 50 deg in winter. I won't see the OAK but knowing there's any moisture or condensation happening there would drive me nuts. Thanks for the info and the sanity checks.



I don't recall reading anything about length of OAK from SBI, but their OAK kit (adapter / flange and vent hood) is 5" diameter - they specify 5" flex pipe, which I think is a lot of pipe for fresh air. My run will be approx 15' - a few inches down from under the hearth / pedestal, a 90 deg bend, then straight across horizontal and out the wall. Scott how much insulation did you need to use around the pipe - inch or 2 thick? or more? Also interested in the "trap" you mentioned - maybe something to add here too since I'm in the process now...?
B of H, I used 1" thick insulation and overlapped it by half, only did it around 5' into the space. i wish I could have insulated it the whole way but I couldn't do it, on count of the way I had my OAK mounted. As for a trap, just make a hump "upwards" with your flexible pipe (creating a little "hill" that the air has to get up and over). My OAK works pretty darn good.
 
Thanks Scotty. Did you use the corrugated dryer-type hose for the entire length? Since air acts like a liquid I wondered if smoother PVC pipe would be necessary for a run that long (obviously not right up to the back of the stove, though- I'd use the metal stuuff close in).
 
Thanks Scotty. Did you use the corrugated dryer-type hose for the entire length? Since air acts like a liquid I wondered if smoother PVC pipe would be necessary for a run that long (obviously not right up to the back of the stove, though- I'd use the metal stuuff close in).
I used some galvanized 4" pipe and elbows, but half of the run is the flexible aluminum dryer vent pipe. It will work fine for that application.
 
In his post "26 of this thread, Scotty Overkill mentioned making a hump in the 4" flexible pipe feeding the OAK. I want to follow-up on this excellent suggestion::cool: When you form the hump, the bottom arc of the hump MUST BE slightly higher than the top of the straight run on the intake side of the hump. Hope this description is clear enough...this is another example of how one picture would be worth a thousand words.:)

How do I know this? Because about 24 years ago while living in Alaska I had to form this hump for a fireplace installation. The only time the hump prevented FREE FLOW of cold outside air into the fireplace was when the hump was bent as described above. The hump DOES NOT interfere with drawing cold air into the fireplace with a fire burning.

Happy holidays!
 
In his post "26 of this thread, Scotty Overkill mentioned making a hump in the 4" flexible pipe feeding the OAK. I want to follow-up on this excellent suggestion::cool: When you form the hump, the bottom arc of the hump MUST BE slightly higher than the top of the straight run on the intake side of the hump. Hope this description is clear enough...this is another example of how one picture would be worth a thousand words.:)

How do I know this? Because about 24 years ago while living in Alaska I had to form this hump for a fireplace installation. The only time the hump prevented FREE FLOW of cold outside air into the fireplace was when the hump was bent as described above. The hump DOES NOT interfere with drawing cold air into the fireplace with a fire burning.

Happy holidays!

guys this is great info- thanks. the outside vent hood I installed is in the center of a rim joist - the horizontal run from hood to stove was intended to go flat across to the stove, between 2 floor joists (up out of the way for the full run) then 90 deg up into the pedestal. I think I might have mentioned somewhere that Osburn recommends a 5" pipe (which I now have) which would not allow me enough "head room" to do as you mentioned (assuming the hump is bent upward). So - would it matter if I bent the pipe downward instead - same idea -but in this case, the arc in the hump would be below the bottom of the straight run - again no free flow - like taking the suggested design, an "inverting" it. What to you think?
 
bag of hammers, Your modification probably would accomplish the same goal. The cold air probably would not cimb out of the dip unless encouraged to do so by a "draw" from the stove. However, the dip might accumulate moisture/ice, debris, etc. sucked in through the vent hood by the burning fire. If that section of intake pipe has easy access it might be worth the experiment. Heck, it might even be worth the experiment if the dip is somewhat difficult to access.

I do believe that if your "dip" modification to Scotty's idea works, you will be very happy with the results.

Good luck and best wishes! :)
 
This is a fairly easy spot to get to (my crawl space has inside access) so that might be the plan. Now that I'm thinking about it, it's kinda like a p-trap for the stove air flow. I never would have thought of this if not for Scotty Overkill and yourself. Definitely worth a try. Thanks again.
 
So the purpose of the hump would be o keep cold air from entering the stove when it was not in use?
 
I just replaced a stove and added an OAK. The new stove is lighting easier and I do not have to worry about whether or not the dryer/water heater/furnace is running when I go to start. I use a torch to guarantee I have a good updraft before I light. I wait until I feel the first foot of stovepipe is warm. This is happening much sooner with the OAK.

If it is pretty easy to install I would definitely do it. Mine hooks right up to the bottom of the stove.

MnDave
This makes no sense.
If your drawing cold air from outside with the AOK, how is this helping the stove draft faster?
I can understand using the torch to heat things up, although you have a draft issue to start with if needing a torch to get it to draft every time you light it.
But AOK air is much cooler, even colder than if it was taking inside air, so it would help draft less than the warmer inside air.
Sounds like wishful thinking to me.
 
When I get my stove, I will make sure its a model that will accept an OAK. Past the fact that it will be pulling in colder, denser air... it also keeps that warm (and humidified!) air in your house. One of the biggest gripes Ive always heard about woodstoves is how dry they make a house feel... makes total sense when the stove is consuming all that moist air in your house!
Ain't bying that one, but hey, whatever sets your mind at ease.
Heating the same "stale" air constantly, is going to be a hell of a lot drier than air infiltrating from outside.
AN outside source of a humidifier would benefit both ways.
 
interesting topic but after all done its a fire nothing more or less, i don't think it needs to be so technical , i clearly understand the hump as cold air would struggle traveling over it. (cold air sinks is my thoughts) when the fire is burning then it would pull the air through, but when fire isn't burning i think it would need some shut off device or it still would suck the air slightly, just my thoughts on it.
 
Machria, you are correct...the purpose of the hump is to prevent cold outside air from entering the stove when it is not burning.

Allow me to add one more clarification to what I have posted above: If your stove is located above the OAK air intake, as seen in the second link I posted in my reply #19 above, there is no need to bend a "hump" into the OAK intake pipe. The cold outside air will not travel up the vertical pipe to the stove unless an outside influence (fire in the stove) causes it to do so.

For example, my OAK intake pipe has a 3' horizontal run from the OAK intake hood to the 90 deg. elbow where the intake pipe goes vertically about 3' to the bottom of the stove. Cold outside air DOES enter the 3' section of horizontal pipe but that air DOES NOT travel up the vertical pipe when when there is no fire in the stove. How do I know this? Simple-on a cold day when there is no fire in the stove I open the stove door and feel the intake slits just beneath the door. They appear to be about room temperature and certainly aren't cold. On a VERY COLD and WINDY day when there is no fire in the stove, I can sometimes feel a cold draft coming DOWN the chimney, into the firebox. However, that situation is so infrequent as to not attract my attention.

For the record: I have no personal interest in whether someone does or does not have a woodstove, an OAK, or a hump in the OAK feeder tube. My only purpose in participating in this thread is to provide my limited experience in the matter. Readers are encouraged to pick and choose tidbits, if any, which interest them.

Now, I am off to place a couple of large maple splits on the simmering coals in my Spectrum.

Best wishes, good luck and happy holidays to all. ;)
 
Ain't bying that one, but hey, whatever sets your mind at ease.
Heating the same "stale" air constantly, is going to be a hell of a lot drier than air infiltrating from outside.
AN outside source of a humidifier would benefit both ways.

That is the thing though... its not 'heating the same stale air...".. its physically consuming it, and it gets replenished by slight insulation leaks and similar constantly. With an OAK, you are pulling exterior air, which has no effect on the air in your house.
 
  • Like
Reactions: John_M
OAK's only supply "primary" air, correct???? So when cruising; with secondaries dancing, you have the primary air damped mostly down....................the stove is drawing "inside" air to the secondary tubes and the doghouse from other locations on the stove. Well with my stove anyway.
 
OAK's only supply "primary" air, correct???? So when cruising; with secondaries dancing, you have the primary air damped mostly down....................the stove is drawing "inside" air to the secondary tubes and the doghouse from other locations on the stove. Well with my stove anyway.


Bump to the top.

Can anyone answer my question??? I understand the theory behind the OAK's, but what if your stove pulls doghouse and secondary air from "other locations on the stove..............not being OAK supplied???? Kinda defeats the purpose in some way............hey???
 
dorkweed, I am not familiar with the Englander line of stoves. Therefore, any info I might offer would be a hazardous guess at best. One can assume you are looking for reliable info and not hazardous guesses.

Good luck and best wishes.:cool:
 
dorkweed, I am not familiar with the Englander line of stoves. Therefore, any info I might offer would be a hazardous guess at best. One can assume you are looking for reliable info and not hazardous guesses.

Good luck and best wishes.:cool:

Danke'.:)
 
OAK's only supply "primary" air, correct???? So when cruising; with secondaries dancing, you have the primary air damped mostly down....................the stove is drawing "inside" air to the secondary tubes and the doghouse from other locations on the stove. Well with my stove anyway.

I do not know for sure.. but yes, I believe it is primary air only. I think that is how these newer stoves are developed... so that you always have SOME air going to the flame (ie... no smoldering). Totally different air path for the secondary fire.
 
I do not know for sure.. but yes, I believe it is primary air only. I think that is how these newer stoves are developed... so that you always have SOME air going to the flame (ie... no smoldering). Totally different air path for the secondary fire.



Thanks............................However; the silence is truly deafening!!!!;hm
 
dorkweed, what is "doghouse" air? I am unfamiliar with that word when used in a woodstove discussion. Perhaps others share my ignorance and therefore do not know how to respond to your query. Another option for you is to start a new thread on just your topic to draw new attention to your interest. There appear to be quite a few Englander 13NC owners on this site and they are always generous in sharing their knowledge with others in need.

Just a couple of thoughts!

Best wishes and good luck.;)
 
OAK's only supply "primary" air, correct???? So when cruising; with secondaries dancing, you have the primary air damped mostly down....................the stove is drawing "inside" air to the secondary tubes and the doghouse from other locations on the stove. Well with my stove anyway.

Stoves are different in design. On my stove the OAK feeds 100% of the air, primary and secondary. Also on some stoves, I "think" the Englander is like this, you have to have the pedestal and it acts as a "plenum" for the air feeds in different locations. So you have to know how your stove is designed to answer this.
 
I just discovered this today from another thread....

My secondaries are pulled from inside air.

I don't have an OAK but my Lopi pulls it's secondaries from rectangular ports behind the heat shields on the sides a few inches from the bottom. The OAK for primary attaches to a cutout on the bottom of the stove. Through this cutout you can view the opening/closing of the primary air.
 
The only down side to an OAK is sometimes during windy conditions you can get a huge draft blowing in but that is rare and the stove will be able to take it okay. When we had one we noticed a lot of difference with a couple different wind directions. We intended to put an OAK in with our last stove but never got it done but all is well.

Another thing is if the clothes drier is run a lot and/or exhaust fans, then and OAK really helps a lot.

Would locating the OAK on the leeward side of the house be a good idea? Would putting it under a porch be a better idea? I have a choice of one or the other.

Also any of you Progress Hybrid guys know where the OAK connection to the stove is? Jut trying to get all my ducks in order before I cut the hole in my floor.
 
Status
Not open for further replies.