Pipe Insulation

[Dymalica]

When people specify aluminum jacketing and insulation for outside refrig or chilled water piping, what is the insulation underneath. Is it better to use like a foamed plastic Rubatex or urethane Armacell? They are not just stuffing fiberglass wrap and then putting aluminum around it are they? What is the best insulation for piping outdoors?

Thanks

 

[DRWeig]

I've never seen anything but Armaflex or equivalent. Needs to be weather resistant, which fiberglass is not. I'm sure that fiberglass could be used, but keeping it dry is a problem.

The aluminum jacket will keep it from UV damage, make it last even longer.

My experience and opinion only -- let's see what the others have to say.

Goober Dave

 

[willard3]

For high temp systems there are jacketed fiber glass systems:

http://www.permapipe.com/product_catalog_listing.asp?product=11

There are also aluminum-jacketed fiberglass systems.

 

[IceMasterNH3]

For exterior low temp refrigeration piping (50F or lower) we always use either styrofoam or isocyanurate, no fiberglass. But even more important than the insulation is the vapor barrier, which is either ASJ paper or Saran for straight runs, mastic for the fittings. Then the aluminum jacketing goes on. Check the Dow website for good info on insulation & vapor barriers.

 

[DrRTU]

On external CW & HW we would use Fiberglass piping insulation (Knauf) with PVC jacket (Zeston) or if an older style spec call for Aluminum jacket (Childers). Check 90.1 or the IEC to determine the insulation value.

DX can use a armaflex design with latex paint or jacket to minimize UV degradation.

 

[cry22]

Fiberglass for CHW is OK for locations in a dry climate. Definitely good for condenser water, not much sweat there. Cellular glass should be used for CHW in humid climates.

Of course, PVC, Aluminum or even stainless steel jackets as indicated above are the norm.