Anyone Have Knowledge Of Topping Up Freon In Home A/c Units.

[marc11]

I have got 2 A/C units in the house and decided to add a third, during the installation of third I asked the guy’s to check the other 2, I watched them and all they did was top up the Freon from a small cylinder with a flexi hose and gauge, during the topping up the second A/C the gas must have run out as the guy had the bottle turned upside down and was trying to say that the pressure was low in the cylinder (the A/C unit is not cooling well). I can buy the Freon cylinders down at home pro and believe I can top up myself all I need to know is what pressure is needed in the coolant line and any other information I need to know.

Any help would be greatly appreciated.

[elkangorito]

This is not a simple process. You will need a gauge set identical to the one the other used & you will also need to know how to use it as well as knowing the gas expansion temperature characteristics of the gas used (I assume R22, which will be phased out in about 5 years.) Without the right equipment & the right knowledge, you cannot safely & effectively do this task.

Look at this link to give you an idea of what I'm on about;

http://www.engineeringtoolbox.com/r22-properties-d_365.html

The refrigeration mechanic is supposed to know the ambient temperature if he is to do a proper job. He uses the gauges to monitor suction & head pressures, which have relevance to the ambient temperature. He also should know the maximum head pressures for various gases ie For R22, max head pressure for most types of a/c units should not exceed about 2300 kPa.

In short, get him back to finish the job.

[ballbreaker]

This is not a simple process. You will need a gauge set identical to the one the other used & you will also need to know how to use it as well as knowing the gas expansion temperature characteristics of the gas used (I assume R22, which will be phased out in about 5 years.) Without the right equipment & the right knowledge, you cannot safely & effectively do this task.

Look at this link to give you an idea of what I'm on about;

http://www.engineeringtoolbox.com/r22-properties-d_365.html

The refrigeration mechanic is supposed to know the ambient temperature if he is to do a proper job. He uses the gauges to monitor suction & head pressures, which have relevance to the ambient temperature. He also should know the maximum head pressures for various gases ie For R22, max head pressure for most types of a/c units should not exceed about 2300 kPa.

In short, get him back to finish the job.

All this is good info. You might also check booklet that came with unit or look on the condenser unit, unit outside, for graph label that will give you the suction and head pressures for a given outside ambient temperature.

If you try this yourself be careful and don't exceed recommend head pressure.

[marc11]

Thank you for the information,

It does sound very complex, but after watching the 2 guys fit and prime the last A/C unit I’m convinced I could complete the task my self, basically these guy's were just laborers paid to install a unit, I doubt very much if they were qualified, its standard Thai style "Jack of all trades" "Master of none"

I would like to use a competent qualified person for the task (not an electrician come odd job man who knows a little bit about A/C units), anyone know of any in the Phuket area.