Riser sleeve materials, availability

[davidludt]

After building and firing our batch box at MHA 2015 I realized I had a design I could use to heat a difficult space I've been trying to wrap my head around for a few years now.

I've got a Peter V.D.B batch box project starting in a shop in Vermont in a few weeks and started looking for riser material.
Talking with firebrick engineers company I sourced some 1' tall 8" I.D. 1.5" thick Vacuum formed riser material for $25 plus shipping from Minnesota.

Pretty affordable.. But the thickness leaves me wondering

And I'm not sure that a riser sleeve is a riser sleeve is a riser sleeve
So I'm waiting on a data sheet come Monday...

My other option is the walker riser.. Tested and approved and much much more expensive.. It's thicker, also which I like.

And Still waiting on a call back from from McNeil in NJ

I've hunted for a thread that collates our data and experiences with the different readymade risers available in the USA and come up somewhat short..

Probably worth our time to collate and refine our data somewhat.

Thanks everyone.

[Deleted]

Just to give an idea.

Assumed high temperature conductivity of 0.15W/m*K, which would be about 0.08W/m*K at room temperature,
for a density of about 250kg/m3
Temperature differenze of 500°C inside the riser to the outside.

Heat = Thermal Conductivity / Distance x Area × Temperature Gradient.
Q = λ / Dx A × ΔT.
0.15W/m*K / 0.037m x 0.19 m2 × 500K = 385W for two pieces 770W

Perlite has a high temperature conductivity of about 0.125W/m*K/0.05W/m*K.
Any mixture with clay and cement will have a significantly higher conductivity
3" Perlite, clay and fire cement mixture, assumed high temperature conductivity of 0.3W/m*K/0.15W/m*K

0.3W/m*K / 0.075m x 0.19 m2 × 500K = 380W for two pieces 760W