Webmaster said:
Fact is, a study I have from the Canadian Government shows that regular chimney caps and the type also used on class A, etc. actually outperform many of the wind caps!
For certain constant wind, I think those directional caps with the vanes on top of them might work pretty well - speaking about seashore and similar applications. But, in most cases, the problem is elsewhere and can be addressed by raising chimney, cutting back trees, installing a regular caps, etc.
Being on a bare side of a Mountain in WV, I did not have alot of choices. I tried the Vacu-Stak out of desperation and it worked great.
Being in the mountains, the wind would whip from multiple directions. I had a regular chimney cap, raised, lowered and tried everything to no avail.
After the Vacu-Stak was installed, the harder the wind blew, the brighter the fire got!
I think the key for me was, is that there was not a constant wind from the same direction.