operation pressure

[thanhck]

Dear alls,
I would like to know how to determine the operation pressure (Low/High pressure) of a refrigeration cycle using R22 or R134a.
At my company, we control LP/HP of air-conditioner using R22 at: 4~4.2/18~20kgf/cm2. in near future, we will change R22 to R134s, so how to control the LP/HP of refrigeration cycle? Pls help me!

[Brian_UK]

Hi, do not think in pressures but in temperatures.

[sendhilkmar]

Just check the R134a Pressure- Temperature charts and findout the LP/HP of R134a Corresponding to the R22 operating pressures/ Temperatures.

[Peter_1]

What do you control on the AC's with the pressures you mention?

[thanhck]

Hi, do not think in pressures but in temperatures.

can you explain clearly?
I'm a beginer so i have lot of difficult with refrigerant cycle:(

[toprunner]

You running at -6,5 to -5 degree C evaporation and 46,5 to 51 degree C condensation. Your pressure with R134a should read 2,3~2,4/12,1~13,5 bar.

This is your smallest problem probably, the largest is that you loose a lot of cooling power when change to a crappy refrigerant. I assume you keep your machinery.

[thanhck]

You running at -6,5 to -5 degree C evaporation and 46,5 to 51 degree C condensation. Your pressure with R134a should read 2,3~2,4/12,1~13,5 bar.

This is your smallest problem probably, the largest is that you loose a lot of cooling power when change to a crappy refrigerant. I assume you keep your machinery.

Thanks, I'm more clearly. but temperature running of evaporator of chiller and Air conditioner are different or not?

[toprunner]

Temperature will be same if your compressor is big enough.

[icecube51]

why the change from R22 to R134a ?

if it is because of the fase-out, you will be better to confert to R407C, you will loose about 3% performence.

Ice

[thanhck]

why the change from R22 to R134a ?

if it is because of the fase-out, you will be better to confert to R407C, you will loose about 3% performence.

Ice

My company change from chiller Mc. Quay (R-22) to chiller Trane (R134a)!!!!!

[Peter_1]

.....This is your smallest problem probably, the largest is that you loose a lot of cooling power when change to a crappy refrigerant. I assume you keep your machinery.

Crappy refrigerant? Wait a year or two and you will have to change your point of view completely. R134a will become THE refrigerant for cooling and chiller applications due to its low GWP. R404a and R507c will be banned or highly taxed in the near future

[icecube51]

Crappy refrigerant? Wait a year or two and you will have to change your point of view completely. R134a will become THE refrigerant for cooling and chiller applications due to its low GWP. R404a and R507c will be banned or highly taxed in the near future

Hear Hear, spoken in truth.
when you start to now the wonders of R134a, you never want anything else.
Ice