Third season with a Sirocco 25 insert. We put it in a basement masonry fireplace as a backup heat source for our big drafty house. We burn ponderosa pine, which is particularly handy since we live in a ponderosa pine forest - go figure. The pine does end up with a lot of ashes, but even with a fire every day, scooping the ash once a week is about right.
What I originally envisioned as an emergency heater has now become a daily routine as long as the outside temp is 40F or below. Now my basement man-cave has become the de-rigueur hangout.
Even with the supposedly marginal firewood, the Sirocco does a great job at putting out heat for many many hours. I can get it to go for well over half a day with no problem - as long as I don't care about the glass going opaque. Turning the thermo-damper up a bit so there are a few flames now and then, the glass stays mostly clear.
I usually run with the thermostat adjusted to near, or just past, the end of the "swoosh". Remember - most of the guys with uber-long burn times are doing so with a much larger fire box and bigger loads of wood. I will give good odds that they have black glass as well. Us insert folks are just a bit more genteel . . .
The blowers are always running and the indicator is usually at the 9:00 o'clock position, - I figure this is about 50% speed.
I usually use some low pressure air to blow the fine ash from the cat every other time the ashes are scooped. There have times when fly ash has begun to restrict air flow thru the cat and impair proper operation.
This season I noticed one or two of the rear fire bricks have cracked. I believe this is due to over zealous cramming of big chunks into the little oddly shaped fire box. The bricks are still in place, and I think they will be OK as is as long as they don't fall out or begin to crumble (is that correct
BKVP?)