chimney cap

[cyclone]

One of my previous post were concerning the cracks I had in my Flu and pre fab masonry chimney cap. This past weekend I replaced the flu and chimney cap as suggessted on this web site from some members, and all is well.

I did keep off the spark suprresor and left the flu as is. What I found is it seems my draft is better. I have a down draft stove which is tricky and takes time to get use to. It seems like I can get it into it's afterburn much easier.

Does a chimney draft better without a spark suppresor?

 

[Highbeam]

A chimney will always draft better without the screen than with it. You should leave the cap on there though. The cap can possibly make for a better draft than a capless chimney.

 

[webbie]

Depends on many variables...but because of these differences it is often impossible to tell for certain....in general, when there is wind the cap probably helps things rather than hurts them.

The screen may impede some draft...but probably little, and I think it is a code requirement.

 

[atvdave]

I'd just like to know what a spark suppresor is on a chimney?


Links & pic's?

 

[Highbeam]

A mesh screen either made of expanded steel or welded wire. Just a filter to catch large chunks of floating fire. The holes in the filter are specifically sized but are along the lines of 1/2" so nothing that will stop an actual spark.

Local codes vary on their use. You should consult your local jurisdiction about whether they are required. The majority of chimneys in this world have no such device.

 

[fossil]

NFPA 211 sez a properly sized spark arrestor will stop anything 1/2" in diameter or larger, and let pass anything smaller than 3/8". Where I live they are required. Mine do, in fact, tend to accumulate soot/creosote and can clog up a bit over the course of a season. But I have not yet experienced any sort of dramatic loss of draft from my screens clogging. Seems to me that if I was worried about it, if I simply get a taller cap, with a greater free surface area for flow, I can install a taller cylinder of screen and mitigate the problem. Rick

 

[atvdave]

I see... Looks like I have one on my cap as well. I'm new at this and didn't know what they where. Thanks for the answer.
Dave