Take a look at the copper lines to the compressor, any ice forming on the lines or valves?
Youāre not far from me. Yes, there are a lot of disreputable ones out there. For several years now, Iāve been happy with Advanced out if W-S. Just watch the little add one like changing your capacitor as a preventative maintenance item for $50, when you can get the part for $10.
I did that with our upstairs unit yesterday. It was a couple of degrees off set point and outside you could feel hot air coming out of the condenser. It was doing all it could but itās hard to reject a lot of heat into already hot air.
A meat thermometer works in a pinch.
I believe he intends the vent(s) thru which cold air blows. He's likely interested in the difference between the room temperature air being sucked into your system and the conditioned air blowing out. That would be an initial indication of how the system is performing.
The first house I bought was built around 1903 and didn't have AC or insulation. I fixed both conditions. The AC was the best $2,000 I ever spent. Still the duct work wasn't designed for it, originally being a gravity fed coal furnace, so even though it has ducts upstairs that helped, we still used a window shaker in the bedroom.
One neighbor I noticed put an EZ up tent over his units to keep them in the shade.
I have mine under a shelter. Got tired of having to go out in the winter to break ice off of it so the fan would turn. My A/C tech said there needs to be a minimum space above the unit for air flow. Mine's about three feet from the fan. He said five would be better.
I believe experienced techs expect to see a difference between return and supply in the area of 17 to 20 degrees. I'm not a tech but guess that if you have that (which means your unit is reducing the temperature of the intake air by 17 or more degrees), it's performing as designed.
Umm, I'm going to assume that at 3 years old it is using R410-A, aka Puron. According to my quick web search this stuff was running $6.00 a pound a few months ago. 11 lbs sounds about right for a 3 ton unit or do. While you are paying some for the knowledge of the job, a 1300% mark up seems outrageous. I may be wrong but I don't think R410 requires a license to buy. At that price you might be better off getting the gauges, the gas, oil, and charging it yourself, but then they wouldn't warranty the job.
