Condensate Drain Pan Insulation 1

[Grizzly68]

I've got a 30 year old built up air handler with chilled water coils that need replacing. The AHU is large, 126,000 cfm. The chilled water coil is actually two banks of three coils each. The coils then sit in a drain pan (to be replaced) which sit on 1.5" rigid insulation (to be replaced) which then sits on a 4" concrete curb inside the air handler. I need to replace the insulation but have no idea what to replace it with. The coils will impose a 250 lb/SF compressive load on the insulation and I need it mold and fungal resistant as condensation is a BIG problem in this climate (North Carolina). Any suggestions?
Chris

 

[KenRad]

Grizzly68,

I would look at the closed cell products from Dow. Their Styrofoam has a compressive strength of 20 psi, and good water absorption properties. Their Trymer line (polyisocyanurate) ranges from 50-140 psi, and also does not absorb water. These are the only products I use anymore for chilled water pipe insulation, one of the great features being that they show very little compression at the pipe hangars. Both are sold in sheet form, as well as pipe covering.

---KenRad

 

[pennpoint]

Grizzly68
If you really want to spend some money consider Pittsburg Corning SuperK Foamglas.
87psi Compressive; other grades up to 232psi
and operating temperatures -450 F to +900 F

http://www.foamglasinsulation.com

Good Luck
pennpoint

 

[gnordo]

I concur with Grizzly68 on insulation with compressive strength.

Consider Stainless steel material for condensate pan replacement. It will be a major assist in reducing places for algae to form, and also will not rust through.
Gnordo

 

[Yeldud]

Gnordo - Is stainless steel inherently less susceptible to algae formation than say a galvanized or painted steel drain pan? If so, why is that the case?