Phase Change User Guide

People are asking sometimes about it, so I decided to make a guide. Please make it sticky if possible. It's for all single stage cooling, including a chillers too. It's for the information and safety purposes. For cascades it's one more rule - do not start 2nd stage, before 1st is not cold enough. But cascades have more protection devices, temperature relays etc.

Phase Change User Guide (Single Stage):

1. It’s plug and play. No need to refill gas or any maintenance.

2. Mount cooler on the CPU/GPU, start the platform, warm up a TIM till 40-45C on evap, then start the cooler.

3. After first (cold) start wait till cooler reaches its operating temperature and compressor get warm. Then you can start running some benches. When compressor is hot, it will take less time.

4. Full performance is reached when compressor is running hot. That’s operating temperature - even 90-110C.

5. Try do not move suction line, when it’s frozen. Bending may cause a damage.

6. After turn off wait 10-15 min till next start. Pressures have to balance. Otherwise compressor won’t start, protection will kick in and you’ll have to wait anyway. In bigger compressors it may turn out fuses in the grid, especially when you have a lot of devices connected.

7. Evap will get dirty after some time. It’s good to clean it sometimes with sandpaper or scotch brite pad.

8. For better results you may add some active cooling to compressor, it can give couple degrees. Especially when cooler is on cosy case with small condenser. Prometeia is the best example.

9. If you have a break (dinner or sth) leave it running. After turning it off, you’ll have pretty quick defrost of whole platform.

10. Ambient temperature affect evap temperature. Lower ambient = lower evap temperature.

11. And last one – if something went wrong. If you accidentally broke a pipe/suction line and gas will start leaking turn everything off, let it escape and open the windows to improve ventilation. Together with gas, oil may be escaping too making an oil stains. Just put a paper towel/shirt whatever to stop it. It will stop after 2-3 minutes. Leaking gas may cause frosts on skin, but you have to keep fingers/skin for a longer while exactly in the leak place. Single stages are charged with R404/R507/R134, these are commonly used refrigerants in AC, fridges etc., they’re not flammable or dangerous for people, but may cause dizziness when concentration in the air is significant. Just like dry ice fumes. After gas is gone and open pipes are left, seal them with tape/rubber plug whatever to prevent contamination the oil and look for somebody to repair it. If you break pipe in the fridge or hose in car AC. it will look exactly the same.

i would like to add some tips at point 6.

you need to wait 10-15min only if the compressor electrical wiring is PSC ( Permanent Split Capacitor) that is using regular on the rotaryes but aslo you can use CSR ( Capacitor Start and Run)electrical wiring that is used usually on the reciprocating compressor in specially LBP(low back pressure) application , that mean heavyer start. because suction pressure will be near 0 bar or a bit above ..to archieve low evaporating temp!

R407c/R410a rotaryes are not designed for LBP aplication , they are for MBP/ HBP (medium/hight back pressure), that mean suction pressure will be at 5-7 bar so the start will be SOFT , so PSC wiring match perfect , but we phase changer convert the rotaryes into LBP application specifical for R404a/R507 so we will run the compresor near 0 bar to archieve low evaporating temp , but electrical wiring it using PSC ...that way you will need to waiting 15 min after start to start it again!

normaly we need to use CSR electrical wiring also on rotaryes , but that mean will add another cap and realy ..and that will rise the cost of unit!

I want to introduce this system
Do I have to make this myself?
Is it something you can buy?
Is it possible in Japan?

12 hours ago, GTI-R said:

I want to introduce this system
Do I have to make this myself?
Is it something you can buy?
Is it possible in Japan?

You could contact bartx about possibly building one or order one from LD Cooling.

http://www.ldcooling.com/shop/14-phase-change