ac Freon refill

[pepmyster]

Hello to all!!!!! I had a problem which was answered to the cause of one of my ac units frosting up. The logical solution was that it was low on Freon, ( thanks Hans). Has anyone done this to their units? I found the the service port which was labeled "suction". Makes sense. If you have done this, what did you use as a product? I'm almost sure it's R12. Thanks in advance.

[tomschauer]

Depending on the years its either r-22 or r-410a.
It should have a label stating the refrigerant type and the charge weight.

[g36]

You must make sure what refrigerant is in the unit. There should be a label for kind and amount it is using.. If you don't have any guages then your just blindly putting it in, which isn't the best option . It can be done but you can also screw it up and can be dangerous ,Also if your low you have leak., if it is r12 its pretty expensive now if you can find it.

[buster53]

Source of the post I'm almost sure it's R12.

Before doing anything, you need to BE Sure, not almost sure.

[pepmyster]

2004, You could be right about the R22. I read a lot and many have written that it was R22.

[tomschauer]

Its definitely not R-12.
For 2004 it should be 410a, but could still be 22.
22 is quite expensive now. About $35 a pound wholesale.
So if its low, you want to find and repair the leak, not just juice it up.

[pepmyster]

I get that. It must be missing just enough Freon to frost. It working but frosts. After all those years, not surprised it missing a bit.

[tomschauer]

Low airflow will also make it frost.
Dirty coil etc.

[pepmyster]

I cleaned the condenser, air filter. checked the fins. I put a fan directed at it also, same result.

[km1125]

Source of the post Low airflow will also make it frost.
Dirty coil etc.

^^^THIS.

I've had a lot of spirited "discussions" with folks on this topic. If you're passing enough 80F air over something, it CAN'T freeze. Something must be restricting the flow somewhere for the evap to even get close to freezing temperatures.

Low pressures in the system will lower both the condensor and evap temperatures, but if the evap coils have enough flow over them the refridgerant will absorb all the BTUs they need to get the temps over freezing VERY quickly. There may be portions of the evap coils that don't get flow that get cold and establish frost or ice, but that should never grow over the rest of the coil if there is enough return air flow.