Small Contest for a nice Christmas Gift

[jan]

Lets see if i this works out nicely. It's been a while since i've built a singlestage

I went to the garage and collected some parts to start with...

I'll make a simple single stage unit using the following parts:

-ACC GP16FB compressor (16cm³ displacement)
-decent condenser, no pics now as it arrives not until next week (pic will follow)
-some evap that i found in the garage. It fits into the vapo mount so i'll try if its ok.
-CPEV (never used one before )
-refrigerant: R402a

The unit will be mounted on a simple aluminium sheet. I've not planned a case for now.


All parts except the condenser:




Today I prepared and brazed the evaporator. Its an simple stepper design so nothing special. I modified it to increase the surface area a bit.


And always remember, while using a bench drill you should wear your safety glasses.







The cooker helps warming it up. At least a bit.



Brazed and cooling down. Now i've to clean it and lap the bottom.



Today I got some work done. I assembled the suctionline and highside of the unit. Pics below:

First I lapped the evaporator. As my lathe is disassembled right now I did it manually
Start with rough paper and as you progress use finer paper until you get a flat evaporator bottom without grooves.



When I finished this I assembled the evaporator with the suction line.



Next I added the feed line for the CPEV



Now that the evaporator, suctionline and feedline were assembled I insulated it and put the evap into the Vapo mounting kit



This is the condenser I was waiting for:



I did cut in M4 threads for easy fan mounting:



With mounted fan it looks like this:





Now I mounted the compressor on the baseplate



next comes the condenser






Starting with the discharge line. I forgot a access valve, I'll add it later on when I finish the cooler.








Added CPEV and filterdryer










As I ran out of brazing rods the last thing I did was adding the suction line and some insulation:








Ok, here is the last part of my worklog.

I decided to use captube instead of cpev...






I did not have a t-connector to install a access valve in highside so i did one myself





evacuating...



...charging...



...with r402a



Its some time ago I've built my last singlestage so i had to make a new load tester.







255 watt




Insulated evap mounted on loadtester




the insulated unit ready to test






And this is the temp under load. Roomtemp was ~ 20 - 22°C




The temp is not that good. I think the evaporator is not capable of this load. Also I've to change the captube as it is to restrictive. I won't have time for this until early january So this is is the cooler as it is for now...


But I'll change captube and evaporator to yield better performance as soon as I've the spare time for it.

Also I could not test the unit under a lower load as I don't have a variac right now.