Central Air Question
We have an old Ruud central air conditioning system from around the early 80's. The few past years we have noticed that the system is constantly running and taking longer than it should to cool the house. So thinking that it was low on refrigerant, we had someone check the system 2 years ago and they said that it had enough pressure. So this year I took a temp probe that I use to diagnose air vents in a car and placed it inside one of our vents. It is reading about 60 degrees. Now I know on a car that 60F degrees is high and it should be reading between 40F-50F degrees. Does the system appear that it may be low on refrigerant and should I get someone else to check the system?
Answer:
the issues are much more complex than measuring delivery temperature. I don't know where you get your car information, either. If an air conditioner can drop the temperature 20 degrees, it is doing about all it can. Get two thermometers - measure the temperature going in the return air grill and the temperature coming out of the closest supply grill. If the difference is 15 to 20 degrees, the unit is working. If the Freon line outside is sweating, it is a good indication that the gas is close to right. If it is not sweating, you have a problem. If it has a sight glass installed and you see bubbles going by, you have a problem. The air that the fan is blowing out the top of the condenser should be notably warm to hot. The condensate line should be delivering a steady stream of water If you live in a humid climate, it will be quite a heavy stream. Things to check: 1. Clean the condenser, this involves removing the top of shroud, using coil cleaner, rinsing from the inside to the outside. Just washing it off with water is not enough, but it would sure help. 2. Check the filter on the inside. Change the filter anyway. 3. The most likely suspect is leaking duct work or fallen away insulation on the duct work. This is all an oversimplification, but should give you enough advice to understand what a HVAC tech is telling you.