Hitzer 983 window vents

Just curious on how other 983 owners are using the 2 window wash vents. Like ALL of us anthracite coal burners, we want to get the best performance from our stoves without wasting coal and heat. Example: both open , 1/2 open, not at all etc.

Hi
I have a 503 insert which has a different over fire air feed set up but the principle is the same. This is what I do. When I reload my stove I have the over fire system open full. After my blue ladies quiet down and are stable I close down the vent leaving it open only about 25%. I run it this way as per Dean from Hitzers advice to allow for more efficient burning of volatiles and minimize puff backs. When burning wood leave the over fire feed fully open.
Hope this helps.
Gian4

Stingray,I just open then during reloading and close them after 5 or 10 minutes just to help burn off the gas but If I forget to close them I seem to loose heat.Keepaeyeonit

I keep them open all the time, in the interest of keeping the glass as clean as possible as long as possible.

Thanks to all who replied, we all seem to be in the general area pertaining to my question. I have my both vents a little less than 25% open and it works well. Thanks.
FYI, I recently bought another door with the glass for the stove so I can change out when the window gets to much build up. This way after I clean it, I'll always have a clear glass to see the blue ladies. Also, a back up if there was a glass or door problem . Thanks again!