Got a call stating that the air-conditioner was just not doing its job. It remained about 80* while the outdoor temps were about 90*. I arrived to find ac working. Removed cover and saw a almost beer can cold suction line. Pressures were low pressure 75.9 high pressure 275.9. Noticed that the condenser was dirty so I removed cover on back side of the unit so I could wash it down and clean it good. I found that the 14″ supply line had separated itself from the unit. I’d say 50% loss in efficiency. After some UN-planned for work the supply line is now in good order. I cleaned the coils good and now look at the pressure readings. The low pressure side was showing about the same as above. I opted to add refrigerant. I added 2 lbs r-22 and the pressures seemed to rise on both low and high side. I stopped and removed the added refrigerant and additional approximate .34 lbs. This brought the suction down to about 70.6 psi and the high pressure to 251.6 psi. The beer can look on the compressor low side was close. Original readings were LP75.9, HP275.9,EV44.8, CO 124.7, T1 49.5,T2 176.5, SH4.1, ^T 126.9. My final readings were T1 60.4, T2 173.3, SH 19.8 ^T 112.5
EV42.0 CO117.1 LP70.6 HP117.1
The indoor return temp was 72* and the supply was 55* , 17* difference.
Using a Testo 500 learning as I go.
One thing was the condition of the unit before I could really try to diagnose the problem was the leaves and debris inside the unit. The condenser was really dirty.
There was enough debris to slow the water flow out of the unit.
The coil was very dirty as you can tell. It is important to clean as well as possible before making a decision on the refrigerant levels.
In the process of cleaning it was discovered that the 14″ supply line was only partially attached that led to at least a 50% reduction in efficiency.
After some work both sides were reattached and in good condition when we finished.
This looks really dirty and was removed very easily with a water hose, without damage to the fins.
Another thing I discovered was that the installers had covered the entire back side of this condenser with the cowling to the wall. That would make a big difference in the efficiency of this unit. I opted to go ahead and lower the cover to allow complete use of the condenser.
This shows some of the repair. After using the duct tape to hold in position we used some screws to anchor so the same problem would not repeat itself. Pretty satisfied with the project.
This is where I jotted down the notes as I went. Being relatively new in this field I try to document and discover my errors as I go. This is by no means suggesting that this is the right and only way to do things. I am still learning and will try to pass on my experiences as I go. “As always take what you can use and leave the rest.”