Bioburner
Moderator
How close to the house is the termination? I had to extend one a foot, now almost three foot and it eliminated most of our problems. Wind builds a lot of pressure against a homes side.
It's already set close to the drip line of the second story roof with an 11/12 pitch, lets say 18 inches out. I'm going to put a snow stay up there this summer when I paint the house. I'm afraid I need to innovate somethingHow close to the house is the termination? I had to extend one a foot, now almost three foot and it eliminated most of our problems. Wind builds a lot of pressure against a homes side.
When we were having the high winds w/ the Arctic front moving back n' forth through NH this winter, I wrapped the Chimney Cap with 1/8" screen mesh, that really helped to stabilize the draft rate up to 45-50 mph winds - could you make a screen hood to surround / shield the termination cap?
Not for the application here, which is wrapped around the frame on a chimney top cap - the cap has a 1" gap between the top frame piece and where the hood sits along the perimeter, so there is an open air space for venting.
The screen works excellent, keeps a stable draft flow in the chimney. We were getting wind gusts of 25 - 45 mph each time the front moved through the area, I was constantly adjusting / compensating for draft on the stove, without the screen. (If you are concerned the screen mesh will be too restrictive, you can always start with a larger screen mesh, and overlap / attach a piece w/ smaller mesh as needed.)
If you need to fabricate a custom collar, bracket, or frame: 1/8 inch x 3/4 inch x 48 inch flat aluminum stock is what I used here, picked it up at the metal section of the local Home Depot - it's thin enough to bend by hand / using a small vise, drills easy enough, and won't rust.. I used this to make a T-support bracket on the 3" Duravent pipe that exits the stove -> inside the fireplace, when I did the install back in Dec. '14.
So far the bonnet with wire is working, BUT no crazy winds...yet. The thought on the T that was presented, was the wind pressure would pass right through from one end to the other and actually suck out the vent pipe. It seemed like a plausible idea?I guess it would depend on how the T was situated, vs. the prevailing winds hitting outlet(s) .. I only suggested the screen wrap to mechanically attempt to duplicate a natural hedge windbreak. How is the new bonnet working for you?