I own a 10-year old 1.5 ton SG split AC. Throughout I've dealt with minor issues - replaced the evap core once and had a leak fixed in the condenser. Also, on a second 'used' compressor.
In the past month or so the cooling performance of my AC has dropped noticeably. It doesn't "chill" the room properly; the room temperature just feels cool, not cold. I've gotten it checked up from three AC guys, and I've even had the gas drained out, gotten a proper flush and refilled higher quality gas.
The suction (thin pipe) and return (thick pipe) are both cold, the suction line colder as it should. The gas pressure is a-okay; measured at around 4 pm and it was 50 psi. I'm told if it is in the 55 psi range, then its working well and might go up to 60 psi or higher in the peak summer season, which sounds about right according to a little research I did via Google.
There are no leaks. My evap and condenser are both clean. Filters are clean. So what's causing the AC to not pull warm and humid air out of the room properly and get chilled air to come out of the evap?
I should also mention when I pop the front cover open to feel the evap with my hands, it is cool and slightly humid to the touch not cold and dry. The air blowing out of the condenser is also warm not hot as it should be. The drain pipe is kicking out the condensed water properly but it isn't as dense as it should be - when my AC used to work at peak capacity, it would kick out a lot more water, and the condensed water felt noticeably cool to the touch, not "luke cool".
Everything according to the technician's gauge and "intuition" points to a system that is fine, yet the cooling has dropped by nearly 25% in the last month. It was running like a champ last year, in mid-summers I might add.
What do you make of this? A faulty TXV or capillary tube? A bad metering device? I'm just taking shots in the dark here. I've even tried having the gas level increased and decreased, but it makes no difference. Better quality of gas makes no difference. Is my evap or condenser about to go out?
The compressor's good too - it's drawing in the correct amperes (between 0.82 and 0.84). So I don't understand why the evap and condenser are not working as good. Whether its day or night, the AC's performance remains at "cool" and not cold.
Two AC guys kept telling me "pressures are good", there's no leakage, your system is performing as it should. I call BS on that because they did not see it performing a month back. Right now, at an 18 deg C setting, my AC performs as if it's cooling at a 26 or 27 deg C setting. Voltages are good at my home, no issues there.
I also should mention that the suction line freezes on start up for the first four mins and then defrosts. A few minutes later condensation can be seen on both pipes and they are cold to the touch. The evap, however, takes 3-5 mins to start blowing cool air and it takes more about 20 mins for the evap to reach it's max efficiency. As you can imagine, it takes a good 20-30 mins for the room to feel cool, let alone feel cold, as it used to. Also the moment I switch it off, my room starts to get relatively warm.
I have the same guys coming in tomorrow again to do a follow up, but I doubt if they will be able to trace the problem - if anything, they'll find a nice excuse to yank more money out of me - after all, hunting season is in. These vultures go to great lengths to prolong AC issues.
I need ideas and suggestions fast - Ramadan is practically here, and I need my AC to perform like it used to. If possible, please suggest a good AC technician as well. I'm from Karachi.
