# High side and low side pressure readings



## Guest (Aug 1, 2004)

Anyone know what the pressure readings(high side and low side) should be to determine if the system is low on charge. It's been many many years since i've worked on A/C units. I still have the guages but not the memory. I just can't remember. 
.


----------



## HVAC Doc (Apr 1, 2004)

Without the proper superheat/subcooling temp. to go along with it, the pressures mean nothing alone.


----------



## Guest (Aug 2, 2004)

HVAC Doc said:


> Without the proper superheat/subcooling temp. to go along with it, the pressures mean nothing alone.


Is the Superheat/subcooling temps on the unit itself? If not, how do i find them out? Appreciate your help, by the way.


----------



## Guest (Aug 3, 2004)

sh/sc and use a pt chart. Sounds like you aint got a clue. any refrigeration mechanic knows what a pt chart is and should keep one with him. probably aint even e.p.a. certified. sounds like you need to call a pro. Big fines if e.p.a finds out your playing with refrigerant and not certified.


----------



## Guest (Aug 3, 2004)

Unregistered said:


> sh/sc and use a pt chart. Sounds like you aint got a clue. any refrigeration mechanic knows what a pt chart is and should keep one with him. probably aint even e.p.a. certified. sounds like you need to call a pro. Big fines if e.p.a finds out your playing with refrigerant and not certified.


It's not like that at all. If you would look at my original question you'd come to realize I just wanted to know what the guage readings should be for a normal running system so I could tell if it's low on refrigerant. I don't have freon nor was I planning to charge the system up. Nor have I mentioned I was E.P.A. certified to do so. I've installed A/C and heating with the help of another. Like I've mentioned earlier it's been many years. I just couldn't remember what was what. Thus, the question. So, I appreciate the help you've given me. Thanks again.


----------



## HVAC Doc (Apr 1, 2004)

Most manufactures have a charging chart inside the unit (outdoor). Depending on age, it could be faded or missing. Many supply houses have a slide rule chart for figuring superheat/subcooling and all you do is plug in your numbers for indoor and outdoor temps, wet bulb temps etc and see where you should be.


----------

