What insulation is best?

[BlazeBusters]

My partner and myself are currently in an engineering class and we are trying to develop an outdoor portable fire pit that will limit injuries often obtained from open fires. Our development has come to a halt because we ran into the issue about what type of insulation we should use and also how thick it would need to be in order to keep the outside layer of the fire pit cool (or at least so it couldn't burn you).

We currently were thinking about doing some form of ceramic wall or floor tile due to the fact that it is cheap and has a high melting point. It would be greatly appreciated if anyone could tell us if they think that ceramic tiles are a good idea and how thick they think they would need to be in order to keep the outside of the fire pit at a safe temperature.

Thank you very much for you time!
- John Gray

[stonecutter]

Re: What insulation is best?

My partner and myself are currently in an engineering class and we are trying to develop an outdoor portable fire pit that will limit injuries often obtained from open fires.

Too bad you can't offer common sense with your sales package....that is the best way to avoid injury.

Our development has come to a halt because we ran into the issue about what type of insulation we should use and also how thick it would need to be in order to keep the outside layer of the fire pit cool (or at least so it couldn't burn you).

How thick is the desired final dimension? At any rate, most of the heat is not contained in a fire pit, so minimal insulation is needed.

We currently were thinking about doing some form of ceramic wall or floor tile due to the fact that it is cheap and has a high melting point. It would be greatly appreciated if anyone could tell us if they think that ceramic tiles are a good idea and how thick they think they would need to be in order to keep the outside of the fire pit at a safe temperature.

If the tile isn't a refractory product, it will not hold up to continuous thermal cycling. Melting point doesn't help you here as much as the materials ability to withstand rapid heat up and cool down(thermal shock). Your best best is a low duty firebrick (full or splits) or a refractory product with low conductivity. The higher the conductivity of your product, the thicker your insulation should be.

Remember that cheap can be twice as expensive if your products fail.