PDA

View Full Version : Insulation



nuclear
08-01-2004, 10:31 AM
Finally got around to working on chiller #1 this weekend.

(I say #1 because, obviously my first..but definitely not my last as I intend to work on which designs are best and what combo of materials works)

Today's topic...insulating the res.

Originally I was going to build a custom res using acryllic but set those materials aside for the time being and decided to use the ever-popular Rubbermaid slim cooler.

A few things I've learned...insulating this cooler is a pain. The main problem is the fact that the cooler isn't a rectangle...internal or external. I opted not to further insulate the interior since I really did not have enough room to fit both the evap and my Hyrdor L30 pump. The pump is smashes up against the evap and impossible to get it to the bottom as it narrows towards the bottom.

I used 3/8" hard neoprene and a healthy roll of duct tape on the exterior, along with some 3M all-purpose spray adhesive. Insulating the exterior is also not an easy task ...again, since it has a curving surface rather than flat.

After much taping, gluing, etc I managed to seal it up as best I could with the materials at hand.

Today's low temp (2 hours running) is -31.2C and slowly dropping still.

Definite improvement over yesterday's -27.4C where I had simply wrapped the exterior in the neoprene without attempting to bond it to the surface of the cooler.

Not noticing any condensation--yet--however the neoprene is definitely cool to the touch and the duct tape even cooler. I'm sure the geek answer is "there can never be enough insulation." Normally I'd agree but in this situation (window AC unit) I'm running out of room to work with both on the bottom and back of the cooler. (Bottom because I can only lift the cooler so much higher before I put the copper tubing in jeopardy and back because I'm pushing closer to the condensor fan and compressor.)

I'm wondering if I should go ahead and lay on another layer of insulating material of some kind? I imagine I won't see much of a temp gain by doing so, but the simple fact that the exterior is cool gives me the "not good enough" bug that seems to be common here :)

My next project will most definitely use a custom res. The cooler is a good start for anyone new and in a hurry...but after working with it for several days my opinion is that it makes insulating a very difficult task due to the shape.

pythagoras
08-01-2004, 12:26 PM
You could build a box round it with a 2 inch or whatever gap around the sides and fill that gap with expanding foam, quick and cheap.

Regards

John.

i_jester
08-11-2004, 07:26 PM
For mine, I built a box from 1/2" polystyrene insulation about 3/4" to 1" from my reservoir and filled the space with the low expansion foam in a can.