Wind directional caps do work!
We live on the coast of Massachusetts and get substantial wind. I have referenced Hearth.com through the years to help me troubleshoot a persistent wind issue with our Jotul 602 with 6 inch double wall Duratech chimney. It is a straight run, 10 feet from any roof line. But the shape of our house at ten feet away does have a 12 ft vertical wall to the south that the chimney exit doesn't clear. I assumed this was creating turbulent air and pushing back against the wind and essentially blocking the exit of the chimney.
All of which was manageable except for when the wind came from the North... which is the direction the worst storms come from where we are. The stove had terrible draw unless I opened the front vent fully during northerly winds and with gust above 20 mph, the stove would send smoke and carbon monoxide back into the house (especially during start up), which was always traumatizing and miserable on the coldest days of winter. We developed a process of quickly removing all of the fuel out of the stove, moving outside, putting water on it and shutting the stove down when the wind picked up. Eventually we religiously checked the wind report days before and would avoid the stove completely with blankets and space heaters.
I attempted every remedy that I could find online to fix the problem. Better seasoned wood, opened windows near and away from the stove, extended the chimney run by 6 ft, and added a Vacu-stack chimney cap. None of which worked. The only remedy left was to continue to add to the chimney until it cleared the southern roof line, which would mean the exterior chimney run would need to be 12 feet, which would have nearly impossible to secure and more importantly, would have looked ridiculous. I assumed we had chosen the worst spot in the house for the stove and that it would be a problem every time the Northerly winds came along for the foresseable future.
Long story short, I decided to make one last ditch effort and ordered a stainless steel pivoting wind directional cap (because of the double wall chimney pipe I am using, I was required to buy an adapter too.) from Luxury Metals. It arrived yesterday as Winter storm Orlena was hitting, but the snow hadn’t started to fall. I made the questionable decision to get up on the roof and switch out the vacustack with the new pivoting cap. I am very happy to say that I am sitting next to a wondrously warm stove with essentially perfect draw in consistent 35 mph winds/45 mph gusts. I even held a piece of smoldering paper 6 inches from the open firebox and the smoke was drawn into the stove and out the chimney. (Maybe too much draw?)
I am still perplexed as to why the Vacu-stack provided almost no change and the directional cap essentially solved our problem. It might eliminate my assumption that the wall 12 ft southerly wall was causing the primary issue… but unsure. I have heard stories of the Vacu-stack caps working perfectly for others and was attracted to the “no moving parts” aspect, but I could have bought four pivoting caps for the amount I sunk into the other failed remedies.
It definitely is fascinating that every situation seems to need a different solution and glad this forum exists. Just so happy that the search was worthwhile and hope this can be helpful for others with this frustrating problem.
Link to the successful cap page:
High quality chimney caps in copper, stainless, and galvanized steel to protect your chimney and prevent downdraft
www.luxurymetals.com