New condenser, old evaporator

[talkinggoat]

i recently had to have the condensing unit changed out, in my home. the unit is a 3 ton 13 seer amana condenser. i don't know what the evaporator brand is, but it's about a 10 seer with the same tonnage. The amana unit is only about 2 months old, but when it runs, sometimes it squeals, sometimes the fan does not come on, and sometimes it acts like it's straining to compress the refrigerant. it acted fine, for about a month, then, one day, i walked outside, the compressor was running, but the cooling fan was off, and the compressor was squealing. ever since then, it exhibits the signs above. i had an a/c tech come out and look at the unit. he advised that the condenser is too inefficient for the evaporator, and the refrigerant is reaching the compressor in a liquid state.

now, i know the basics of how refrigeration works, but i'm no expert, although, i'm a quick study.i do build computers, so i know how to read a wiring schematic. i noticed that the condenser has a 2 speed fan, so i had him buy pass the low speed, to make sure that it wasn't the speed switch. so far, i have not noticed the compressor running with the fan off, but it has only been a day.

does the guy's theory about liquid refrigerant reaching the compressor hold "liquid refrigerant" he didn't take any pressure readings from the lines.

[Charles Schuler]

Without readings, he was flying by the seat of his pants.

[udarrell]

You have problems!

- udarrell

[talkinggoat]

i just spoke to someone regarding this issue, that i know i can trust. he advised that if the evaporator were not vaporizing the refrigerant, the compressor would be making a chattering sound, from the valves, not a squealing sound. he seems to think that it overheated or it is not getting oiled properly.

the ac tech is trying to say that because the condenser is seer 13 and the evaporator is seer 10, it is causing problems with the compressor by not allowing the refrigerant to vaporize.

as far as i know, seer is just a measurement of efficiency, not a measurement of btu or tonnage, and would not have the same effect as putting a 4 ton condenser on a 3 ton evaporator, for example. am i correct in assuming this?

my condenser and evaporator are both 3 ton units.

[mm]

I know nothing but this doesn't strike me as right. Also that he didn't make any pressure measurements strikes me as ridiculous.

Combine your first and second posts, and post to alt.hvac or something like that. I hear they are prima donnas there, but I think they will like your question.

That would be my guess. I have no real idea if we are correct, but I was thinking just like you are.

I only know one AC, my own, and I don't know it too well, but I'm pretty sure it is wired so that whenever the compressor is on, the fan is on too. That is also clear from the wiring diagram that is either in the papers I have or inside the cover of the compressor box.

BTW, before you post to alt.hvac, where they don't just answer everyone, you should learn to capitalize where the rules require it.

A) Not every font makes the difference between a comma and a period clear, so I had very little idea of what you said in your first, first paragraph, which I quote below.

B) You look like a blooming, self-centered adolescent idiot who was too stupid or lazy to learn how to use capitals***, or -- and please tell me this isn't true -- thinks he is expresssing himself, thinks he has something worth expressing, by being different or not following the rules. The rules were created to make text easier to read, and it's even worse here because you're coming for favors. Don't be a double jerk.

***In which case, trying to help you with your AC will likely be futile.

You wrote. afaict, contradicting yourself in the process: i recently had to have the condensing unit changed out, in my home, the unit is a 3 ton 13 seer amana condenser, i don't know what the evaporator brand is, but it's about a 10 seer with the same tonnage, The amana unit is only about 2 months old, but when it runs, sometimes it squeals, sometimes the fan does not come on, and sometimes it acts like it's straining to compress the refrigerant, it acted fine, for about a month, then, one day, i walked outside, the compressor was running, but the cooling fan was off, and the compressor was squealing. ever since then, it exhibits the signs above, i had an a/c tech come out and look at the unit, he advised that the condenser is too inefficient for the evaporator, and the refrigerant is reaching the compressor in a liquid state.

Some of your sentences are too long also

[ds549]

the evaporator needs to be clean so the freon goes to a gas . if the condenser fan isnt running your not pulling the heat off the freon before its pumped by the compressor.

[talkinggoat]

yes, the evaporator does need to be clean, otherwise the refrigerant won't vaporize, but it is clean. i took it out and checked it myself.

the fan not running would make the a/c far less efficient and would put another mark against the compressor overheating, but it would make it even less likely that the compressor is receiving a liquid from the evaporator. as soon as the freon passed the expansion valve, it would be hot, and start to boil.

if the evaporator could not do its job in vaporizing the refrigerant, wouldn't it freeze up?

[Dave Martindale]

The refrigerant goes to the condenser *after* the compressor - it's on the high pressure side. The condenser's job is to take high-pressure hot gas and convert it to high-pressure cooler liquid. The condenser fan should either start with the compressor, or it should start a few seconds later under the control of a pressure switch as the high-side pressure climbs after compressor startup.

Dave

[Bob Pietrangelo]

You probably got what you paid for. You should have had the evap changed with the OD. Amana is made by Goodman. Where is the contractor that installed it. Why are you having to alter a brand new unit to make it work. Pay some one to come out and match your system and reinstall it properly, then sue the hack who ripped you off!

[Ron]

"in your first, first paragraph" - "expresssing" LOL

Not to mention your misused commas.

Or your double spacing, moron.

[Ron]

I don't know what your problem is, but I do know that seer has nothing to do with it.

And, you can use a bigger evaporator with a smaller condenser, but not vice verse.

[Stormin Mormon]

: > > i recently had to have the condensing unit changed out, in my home. : > > the unit is a 3 ton 13 seer amana condenser. i don't know what the : > > evaporator brand is, but it's about a 10 seer with the same tonnage. CY: Matched for tonnage is good.

: > > The amana unit is only about 2 months old, but when it runs, sometimes : > > it squeals, sometimes the fan does not come on, and sometimes it acts : > > like it's straining to compress the refrigerant. it acted fine, for : > > about a month, then, one day, i walked outside, the compressor was : > > running, but the cooling fan was off, and the compressor was : > > squealing. ever since then, it exhibits the signs above. CY: Something seriously wrong. On most AC, the fan should come on at the same time as the compressor.

i had an a/c : > > tech come out and look at the unit. he advised that the condenser is : > > too inefficient for the evaporator, and the refrigerant is reaching : > > the compressor in a liquid state. CY: A new outdoor unit would have a new condensor, which is as efficient as you're gonna get. Makes me wonder if the indoor unit is a problem. That could cause liquid to flood back to the compressor.

: >

: > > now, i know the basics of how refrigeration works, but i'm no expert, : > > although, i'm a quick study.i do build computers, so i know how to : > > read a wiring schematic. i noticed that the condenser has a

2 speed : > > fan, so i had him buy pass the low speed, to make sure that it wasn't : > > the speed switch. so far, i have not noticed the compressor running : > > with the fan off, but it has only been a day. CY: yes, the outdoor fan should run with the compressor.

: >

: > > does the guy's theory about liquid refrigerant reaching the compressor : > > hold "liquid refrigerant" he didn't take any pressure readings from : > > the lines. CY: It's possible. If there is liquid coming back to the compressor, it sounds like your indoor evaporator is dirty, or low air flow. Or both.

: >

: > i just spoke to someone regarding this issue, that i know i can trust. : > he advised that if the evaporator were not vaporizing the refrigerant, : > the compressor would be making a chattering sound, from the valves, : > not a squealing sound. he seems to think that it overheated or it is : > not getting oiled properly. CY: I'm with you on the evaporator part. As to not oiled, well, the oil is mixed in with the freon.

: >

: > the ac tech is trying to say that because the condenser is seer 13 and : > the evaporator is seer 10, it is causing problems with the compressor : > by not allowing the refrigerant to vaporize. CY: Or, the old evaporator may be totally dirty.

: >

: > as far as i know, seer is just a measurement of efficiency, not a : > measurement of btu or tonnage, and would not have the same effect as : > putting a 4 ton condenser on a 3 ton evaporator, for example. am i : > correct in assuming this? CY: I've heard that it's not good to put a high seer condensor on an older evaporator. Sounds like one of those cases.

: >

: > my condenser and evaporator are both 3 ton units. CY: Best of luck. Let us know how things work out. :