A/C experts chime in: bad start cap from new?

[LVSteve]

4/5 years ago I had a new A/C system installed upstairs. Straightforward Amana 14 SEER unit with a scroll compressor. Came home from vacation this week to find it not working as the compressor didn't run. My diagnosis was that either the compressor had failed or the start cap was bad. Decided to fit a new combo start cap (does the compressor and the fan) as they are readily available, only ~$25 and I can do it. Slapped in the new piece and the unit fired straight up.

Now, I immediately noticed the machine sounded a little different, less labored than it had sounded from new. I originally thought the particular tone was a function of the new style of compressors. I also noted that the air from the registers seemed colder than I recall. Could it be the original cap was bad from the gitgo and dragging down the compressor speed? Would I actually notice a difference in temperature or is that just wishful thinking/placebo effect?

Thanks!

 

[9mmPatriot]

A new start cap will only be in play to start the compressor. Scroll compressors do become slightly more efficient over time, but not so much that you'll notice a difference.

A new filter every 30 days and a thorough condenser coil cleaning will go a long way toward increased comfort, equipment longevity and reduced energy use.

 

[ladder13]

What he said^^^^^^^^^^

 

[Ivan the Butcher]

The new "Replacement" refrigerants, run at almost twice the suction pressure than the old R-22 units. If you are now a little lower in charge, the temp. will be cooler and the pressure lower. This really is not a good thing, but a possible leak indicator. If you can, have it looked before any little problem gets into the BIG problem category.

Ivan

 

[9mmPatriot]

A low charge will cause the evaporator to freeze up, starting at the outlet of the metering device. once the coil is covered in frost or ice there won't be any cooling in the space at all.


Since the OP is a desert environment, dehumidifying is not needed. A 20 Deg. temperature difference across the evaporator coil is damn close to perfect. (74 deg return air = 54 deg supply air.)

 

[LVSteve]

I'm diligent about filters, and the techs that have inspected the systems in details say our house is way ahead of the game compared to many around here.