A/c freeze up

Eugene Silberstein 3

Do you have the temperature at the inlet of the compressor?

Brian_41

A/c freeze up

Service Call;
2 1/1 ton ac
superheat ranging from 3-8 (13 req.)
unit freezes up
od amb:70
id amb:58 wb/72db
high side: 180psi
low side: 55psi
lat: 52
delta p across coil: .24

I tried adusting ref. charge but my suction pressure went way low, readusted back to how I found it. I think that air flow isnt an issue. This is fixed orifice. Is this a restriction issue?

Eugene Silberstein 3

A couple of Quick Things

You asked if there is a restriction issue. The answer is NO. Why you ask?

If you had a restriction, you would be underfeeding the evaporator coil and your superheat would be higher than desired. In this case, your superheat is low.

Low superheat is one indication of reduced airflow through the evaporator coil. How do you know that there is not an airflow problem? What have you done to check this?

One other thing to consider is that your outside ambient temperature is 70 degrees and your indoor ambient temperature is 72. Your evaporator coil is very likely to freeze given that under those conditions, the system is actually too efficient.

To verify this, grab the following set of readings:

Evaporator saturation temperature.

Evaporator outlet temperature.

Condenser saturation temperature.

Condenser outlet temperature.

Compressor inlet temperature.

Compressor amperage draw (actual, not nameplate).

Voltage supplied to the compressor (actual, not nameplate).

Give me these pieces of information and we'll all have some fun with it.

Brian_41

freeze up


evap sat. temp 30

evap outlet temp 35

cond sat temp 95

cond outlet temp 75

doesnt the delta t of 18 and lat 52 along with .24 press. drop through the coil indicate enough air flow?