Okay, so I've been reading all the posts on whether or not an OAK is beneficial or not and finally decided to test the theory myself. I had been playing with the Englander settings over the last several weeks and think I have the best possible heat output that I can get.
Tonight, 29 degrees outside 72 in the house with the stove on level 3 and OAK hooked up, highest convection air temp was 175 checked for 20 minutes. Next the OAK duct is pulled from the stove and moved about 15 inches away. First thing I note is a good amount of cold air being drawn in through the open OAK so I sealed it with a piece of duct tape. Next I see that the flame is significantly more active and more fly ash is flying around. Within 5 minutes the convection air temp had risen to 187 degrees and remained there over the next 20 minutes. Now the OAK gets hooked back up and within five minutes the convection air temp settled back down to about 175. So here I am thinking there is an advantage to using warm room air vs outside air for combustion when I decide to check the outside cover on the OAK. Small louvers looked normal but kind of tight so I thought I'd open them up a bit and go check the temp again. Well that did the trick, convection air shot back up to about 187 within minutes.
I performed the comparison one more time with the OAK disconnected from the stove and it made no difference in the convection air temp but did pull more cold air in from the base of the front door, not much more but it was noticeable. I'm satisfied that the OAK is a good thing but I will replace the OAK aluminum cover with a screen to ensure it remains free flowing. Now I can stop reading all the posts about the good, bad and ugly of the OAK.
This pic is after I opened up half of the louvers slightly and that's all it took.
![[Hearth.com] Check that OAK inlet](https://www.hearth.com/talk/data/attachments/149/149643-bcfd833b9f25c4ba86b65c63f3cac0fb.jpg?hash=5KkQWXFO_n "[Hearth.com] Check that OAK inlet")
Tonight, 29 degrees outside 72 in the house with the stove on level 3 and OAK hooked up, highest convection air temp was 175 checked for 20 minutes. Next the OAK duct is pulled from the stove and moved about 15 inches away. First thing I note is a good amount of cold air being drawn in through the open OAK so I sealed it with a piece of duct tape. Next I see that the flame is significantly more active and more fly ash is flying around. Within 5 minutes the convection air temp had risen to 187 degrees and remained there over the next 20 minutes. Now the OAK gets hooked back up and within five minutes the convection air temp settled back down to about 175. So here I am thinking there is an advantage to using warm room air vs outside air for combustion when I decide to check the outside cover on the OAK. Small louvers looked normal but kind of tight so I thought I'd open them up a bit and go check the temp again. Well that did the trick, convection air shot back up to about 187 within minutes.
I performed the comparison one more time with the OAK disconnected from the stove and it made no difference in the convection air temp but did pull more cold air in from the base of the front door, not much more but it was noticeable. I'm satisfied that the OAK is a good thing but I will replace the OAK aluminum cover with a screen to ensure it remains free flowing. Now I can stop reading all the posts about the good, bad and ugly of the OAK.
This pic is after I opened up half of the louvers slightly and that's all it took.
. Check your OAK to ensure it is clear is the moral of this story.... 
