Evaporating Pressure

[Abe]

What should the "ideal" evaporating pressure be on a R410 split air conditioning system, in cooling mode in a 30C ambient

Should it be around 150psi ( which is evap temp +10C ) or should it be less.

On a pre charged system how is the charge adjusted??

Same question for R22

Thx in advance

[frank]

What should the "ideal" evaporating pressure be on a R410 split air conditioning system, in cooling mode in a 30C ambient

Should it be around 150psi ( which is evap temp +10C ) or should it be less.

On a pre charged system how is the charge adjusted??

Same question for R22

Thx in advance

Typical mistake Abe.
Never refer to pressures. Look at temperatures using the Saturation tables for the gas you are using. With Air Conditioning you should aim to keep your evaporating temperatures above freezing to avoid frosting on the evaporator. With R22 the saturation temperature at 0C is 49.7psig so most "eng'rs" look for a suction pressure of 50/55psig which ensures that the evap stays free of frost. Likewise you need to look at the sat temp of R410a (sorry, I don't have it to hand) for 0 - 5 C saturation pressure.

from experience it is about 7.5bar

[Abe]

Thx Frank

Actually this morning when I posted , I did really mean evap temp, not pressure.........Grrrrrrrrrrrrrrrr But what the heck

Ive printed it out
Appreciate your help

Picked up an order for 6 systems today, ranging from a couple of wall splits, to cassettes and one floor mounted

and.............also got a cold room!!!!!