Goliath Triple Cooling System

[Sweeper]

Excellent build sweeper, your fabrication skills are amazing. Just one observation, your insulated chamber, you don't seem to have a thermal break between the inner and outer shell where they are joined together (where the lid will seal on the box). This will allow heat to travel through the metal/alloy and into the inner chamber. Whilst this probably won't have much effect on your temps, it will result in condensation forming around the lid seal. All coldrooms and freezers have a plastic section where the inner skin meets the outer skin to prevent this, commercial freezers even have a heater cable in this plastic section to help prevent condensation better, and they only run at -10 to -25c, you're planning on running -40. I think you also might run into trouble with your polycarbonate lid, I think it will allow too much heat into your inner chamber, and I think you'll have a lot of difficulty reaching the desired temp. By comparison armaflex insulation has a thermal conductivity of 0.036-0.04 W/m.k, whilst polycarbonate is around 0.19-0.22 W/m.k (around 6 times higher). If you use a bigger compressor to achieve the temp, you may then have problems with condensation forming on the outside.
Also, how do you plan on regulating the water pressure to 150psi???
Anyway, best of luck with the build, you've got a seriously hardcaore set up there

Thanks for your observation....you have a point about the inner and outer metals joining at the corners. The inner and outer chambers are separated with 1" Armaflex and don't make contact, except at the corners where they are joined together. I was going to seal the joint with silicone and apply a layer of insulation tape......but, this still would not prevent the cold temps inside the chamber from transferring through the joining metals to the outside. So, now I guess the two metals will need to be separated for a thermal break. I will use 1/8" seal tape between the two metals to break contact. Hopefully, this will do the trick! Thanks for pointing it out.

As I stated in a previous thread....the lexan that I will be using is multi layer laminated glass, which acts as a thermal break between each layer. So, I shouldn't have a problem with heat transfer to the inner chamber.

As far as regulating the pump pressure....the pump has a built in pressure adjustment.

Thanks again