hehe
When I saw -50c and better load temps in the shed on 404a I was pretty surprised, but with room temp they came back a little closer to 'normal'
Considering the -40 on a mach2 setup with chilly head and 404a is about as good as it get's, and even then you probably wouldn't quite see it, we're looking about 10c colder or so with the new compressor.
The unit's set up now for 24/7 operation. I didn't want to go 'best temps' by pulling back on the charge and losing capacity. The return temp about 4-5" back from the compressor is around -35idle and -25load, so the compressor is getting a good amount of cooling.
It's the cpu/mobo that needs some good insulation/condensation proofing with this thing. Either a backplate heater or a thick insulation job will be an absolute must with it. Considering how cold your week 13 '55 ran Scorchio, I expect that Boardy's will too, so for 24/7 that's gonna have to be kept in mind.
The controller might be here by the weekend, but if not then early next week. Once that's here I can get things finished up, and decide whether to give the unit fan control with 12v fans, or to go with the more powerful 240v fans that I have here.
The compressor is louder than a standard mach2 one, but to be honest it sounds almost exactly the same as the VapoLS compressor for noise. Considering it's a 404/507 higher efficiency compressor as well that's not surprising.
Ah well, either way it will be done soon and some final specs will be available, but -50 load is pretty much a guarantee on the 402a when it goes in and that's kinda cool. I have a feeling that we'll also be seeing a very small difference between idle and load temps on the evap due to the large capacity of the unit. I set it that high mainly because if you try to restrict the larger compressors too much you can damage them, so it's closer to where it really should be for the load it will be dealing with. I'ts been very easy to tune, so the system balance is good, and when it comes time for 402a, it should work quite well.
Either way, it's about the coldest single stage unit I've ever built, and quite likely will be for a long time
Gray