Skeptical A/C Issue

[moparman915]

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Thanks for the heads up, won't happen again!

[hvacmike85]

A lot of residential guys are briefly trained and sent out on their own, commercial not so much. So if their not purposely ripping you their just incompitent. Find someone that works for a company that might help you on the side they might be more help

[jtrammel]

Do all units come with a piston, fixed orfice or TXV? Does it have to have at least one of the three to function...?

A piston is a fixed orifice. All ac's have a metering device to flash liquid refrigerent to begin the change of state from liquid to vapor thus removing the heat from the air in the process. The 3 types of metering devices are a capillary tube(old ac's have these) , txv, or piston (fixed orifice). Some higher end equipment will have an electronically controlled expansion valve (exv).

[Shophound]

Added 5 lb 1 oz of R-22

Oh my!

If it needed that much refrigerant, you have a significant leak! And a leak that should be repaired pronto! If you have no leak, that system is now most likely seriously overcharged! Which is never good.

Which contractor is this invoice from? #3?

[hvacmike85]

Do all units come with a piston, fixed orfice or TXV? Does it have to have at least one of the three to function...?

yes its one of four must have components. Compressor, metering device, evapoator, condenser

[moparman915]

Oh my!

If it needed that much refrigerant, you have a significant leak! And a leak that should be repaired pronto! If you have no leak, that system is now most likely seriously overcharged! Which is never good.

Which contractor is this invoice from? #3?

This was from contractor #3 when he did the evacuation of old refrigerant and replaced it with 5 lbs of R-22. The process, BTW, included removal of the old/contaminated R-22, purge with nitrogen (or something like that) and vacuum to 500 microns. Then he replaced it after finding no leaks.

[moparman915]

This is some information I found on the invoice about my A/C unit:

Furnace
Model Number
# L1RA054c-12a

Make: Nordyne
Model: FS3BA-036KA ( 3 ton unit; manufactured by Frigidaire in 2003 according to a Google search)

Suction 71
Line Temp 65
Sat Temp 42
Super Heat 23
Liquid 268
Line Temp 110
Sat Temp 122
Sub Cool 12
Amb Temp 94or44
R-A Dry Temp 80
S-A Dry Temp 63
Temp Rise 17
Added 5 lb 1 oz of R-22

Can anyone make sense of these numbers? Are they within normal limits and can they illustrate any potential problems?

[Shophound]

This was from contractor #3 when he did the evacuation of old refrigerant and replaced it with 5 lbs of R-22. The process, BTW, included removal of the old/contaminated R-22, purge with nitrogen (or something like that) and vacuum to 500 microns. Then he replaced it after finding no leaks.

Ah, I see. Easy to lose track of what's been said in these threads. You did mention the above.

That said, #3 did all that but never looked for trash in the piston? He sounds promising but needs to push his diagnostic envelope further.

[beenthere]

The readings aren't out of line. but would need to know indoor wetbulb to know if they are ok.

[rebehanish]

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[rebehanish]

This is the Ask Our Pro's forum, and only Pro members that have been vetted by the AOPC may post advise here. Please apply to the AOPC today, thank you.

You can find the rules for posting and qualifications here.

Further infractions may result in loss of posting privileges.

[toocoolforschool]

A lot of residential guys are briefly trained and sent out on their own, commercial not so much. So if their not purposely ripping you their just incompitent. Find someone that works for a company that might help you on the side they might be more help

X2
From your description you are definatly suffering from lack of experience. Something is causing the coil to freeze and it is definatly not a capacitor on the outdoor unit. Did they replace the Blower motor capacitor, or check the operation of it or see if your indoor coil is cleaned?

[Shophound]

Can anyone make sense of these numbers? Are they within normal limits and can they illustrate any potential problems?

I plugged your invoice data into my Android phone app "HVAC Buddy", assuming a 67 degree wet bulb for that missing data above. It returned a verdict of "high superheat" and stated possible causes as "undercharge (leak) or restriction".

So there you go. An app on a smart phone reached the same conclusion I and other techs here have. How 'bout that?