Was curious what the coles notes are on draft pressures now that a couple guys have started measuring them and have installed dampers.
Any notable improvements in burn characteristics?
I was probably one of those couple guys. I was having problems with clogging the SteelCat combustor in one of my Ashford 30’s, which is on a fairly tall (29 feet, if I recall correctly) insulated 6 inch flue, any time I did extended burning on higher settings. I was also having problems with getting the wood load charred and cat up to temp in bypass mode, before I had a fire raging so hard I was afraid of having a chimney fire. The stove is so controllable, that despite this very high draft, I never had control issues with the bypass closed.
I installed a Magnehelic manometer, and measured my draft on high, 30 minutes after closing bypass. I found it to be 0.16” to 0.18” in a few days of testing in relatively mild weather, which is about 3x higher than BK’s recommended or maximum values. I installed a flue damper, which initially got me down around 0.08”, but with a few days ash fluff deposits on it, I’m now able to dial down to 0.05”.
A week in, I now have another clogged cat, but I’m not ready to all this experiment a failure. I’m not sure I was successful in getting it clean when I installed the damper, as it’s just about impossible to vacuum it clean in the stove. I try compressed air on it, which is not recommended, but I can’t find any other way to get them un-clogged in-situ. I have new interam gasket on the way, so I can remove it and give it a proper cleaning, before re-testing.
I have noticed a dramatic improvement in how the stove comes up to temperature on a reload. No more furious raging fire in bypass mode. It just comes up to temperature nice and gentle, like my other stove on the 15 foot chimney. That is a nice improvement.
More data to follow, once I get this cat cleaned. I’m not sure it will be totally conclusive until I try it with a new cat, this one is 3 years and 15 cords old and has been blown and vacuumed clean many times, but I’ll post what I find either way.