We recently had our air conditioning serviced by a professional contractor. Was low on R-22, no
leak found so he charged it up.

Since then we have had some intermittant problems (no cooling). Put some meters on the outside unit
with the low side 120 psi and the high side ~175 psi.

I called our air conditioning contractor (1 week backlog) and he believes it is probably the reed
value in the compressor and the compressor needs replaced. For those who care, this is Lennox.

Wanted to double check if this makes sense. Any input appreciated.

Thanks. Direct replies to: firefly24 comcast net (insert @ and .)
Gary.

are you saying the low side is in retard (vacuum) or is greater than 120
psi?

the title says one thing and the text of your message says the other

either way, it is VERY unlikely that a "reed valve" in the compressor would
cause either reading

please post the correct high & low side pressures you measured and the
ambient temperature they were measured at

PS - if your unit was truly "low on R-22", then it has a leak, they just
don't use up some like a car uses a little oil!

sounds like you need an A/C contractor who is competent




"NewsReader" wrote in message
...
We recently had our air conditioning serviced by a professional
contractor. Was low on R-22, no
leak found so he charged it up.

Since then we have had some intermittant problems (no cooling). Put some
meters on the outside unit
with the low side 120 psi and the high side ~175 psi.

I called our air conditioning contractor (1 week backlog) and he believes
it is probably the reed
value in the compressor and the compressor needs replaced. For those who
care, this is Lennox.

Wanted to double check if this makes sense. Any input appreciated.

Thanks. Direct replies to: firefly24 comcast net (insert @ and .)
Gary.

"NewsReader" wrote in message
...
We recently had our air conditioning serviced by a professional contractor.
Was low on R-22, no
leak found so he charged it up.

Since then we have had some intermittant problems (no cooling). Put some
meters on the outside unit
with the low side 120 psi and the high side ~175 psi.

I called our air conditioning contractor (1 week backlog) and he believes it
is probably the reed
value in the compressor and the compressor needs replaced. For those who
care, this is Lennox.

Wanted to double check if this makes sense. Any input appreciated.

Thanks. Direct replies to: firefly24 comcast net (insert @ and .)
Gary.


This is Turtle.

What you have stated here means nothing. If the compressor was not running and
you got these readings. It means nothing.

Now have it running and then get the readings ! Also a model & Serial number of
the unit and what type system it is Split, Package, or heat pump split or
package would be nice to see.

TURTLE

OK, I get what you mean, it is showing in the "retard" area, because you
pegged the meter 360 degrees around!

if the freon level was correct, and the system was running when you took the
measurement, you have a worn compressor, although it would be the primary
compression area of the compressor, not the reed valves.

before jumping to any conclusions and tossing what might be a perfectly good
compressor, insist that your contractor completely evacuate the system,
leaving the vacuum on a full hour, then WEIGH IN the freon charge as per the
amount listed on the information plate.

there is no other way to accurately determine the correct charge, other than
weighing it in, no matter what any contractor might incorrectly tell you.

it is not like the gas gauge of a car, no meter or gauge set can tell you if
the freon level is correct, weighing it in is the only precise way, due to
reasons of chemistry & physics, all other methods are a guess.

freon level must be correct to be sure a compressor is the actual culprit

cheers!

wild bill

"TURTLE" wrote in message
...

"NewsReader" wrote in message
...
We recently had our air conditioning serviced by a professional
contractor. Was low on R-22, no
leak found so he charged it up.

Since then we have had some intermittant problems (no cooling). Put some
meters on the outside unit
with the low side 120 psi and the high side ~175 psi.

I called our air conditioning contractor (1 week backlog) and he believes
it is probably the reed
value in the compressor and the compressor needs replaced. For those who
care, this is Lennox.

Wanted to double check if this makes sense. Any input appreciated.

Thanks. Direct replies to: firefly24 comcast net (insert @ and .)
Gary.


This is Turtle.

What you have stated here means nothing. If the compressor was not running
and you got these readings. It means nothing.

Now have it running and then get the readings ! Also a model & Serial
number of the unit and what type system it is Split, Package, or heat pump
split or package would be nice to see.

TURTLE

Hi cowboy, hope you are having a nice day

On 15-Jun-05 At About 15:24:47, cowboy wrote to All
Subject: Suction in retard, Liquid at 175.

c From: "cowboy"



c there is no other way to accurately determine the correct charge,
c other than weighing it in, no matter what any contractor might
c incorrectly tell you.

Actually there is a way to check the charge properly. depending on the
metering device superheat or subcoooling. weighing the charge in is a start
but you should always check with the proper method above to insure that you
are correct.


... **FLASH** Eveready Bunny arrested, charged with battery.

___ TagDude 0.92á+[DM]
++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++
spam protection measure, Please remove the 33 to send e-mail

I presume these pressures were with the outside compressor running?

Yep, those pressures do suggest bad valves.

--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.com


"NewsReader" wrote in message
...
We recently had our air conditioning serviced by a professional contractor.
Was low on R-22, no
leak found so he charged it up.

Since then we have had some intermittant problems (no cooling). Put some
meters on the outside unit
with the low side 120 psi and the high side ~175 psi.

I called our air conditioning contractor (1 week backlog) and he believes it
is probably the reed
value in the compressor and the compressor needs replaced. For those who
care, this is Lennox.

Wanted to double check if this makes sense. Any input appreciated.

Thanks. Direct replies to: firefly24 comcast net (insert @ and .)
Gary.

Please.

We refer to them as mentally challenged and not retards.

And why are you checking his suction???

HvacTech2 wrote:
Hi cowboy, hope you are having a nice day
Subject: Suction in retard, Liquid at 175.

Hmmm my guess... OP, those reading were taken with the unit not
running... and if it has pure R-22 in it, the temperature of the
equipment that day was about 95F, is that right?

Got that info from the "vapor pressure scale" on my gauge set.

c From: "cowboy"
c there is no other way to accurately determine the correct charge,
c other than weighing it in, no matter what any contractor might
c incorrectly tell you.

Actually there is a way to check the charge properly. depending on
the metering device superheat or subcoooling. weighing the charge
in is a start but you should always check with the proper method
above to insure that you are correct.

Yeah cowboy, what HvacTech2 said. :/

I'm still in the process of getting a handle on this super-heating
and sub-cooling thing myself. It's kind of tricky but is "the way"
the engineers figured out what the charge weight should be to start
with. First things first. Know what I mean, Verne?

What I want to see is an explaination on how to measure and adjust
SH and SC using only the pressure readings, the R-22 scales on the
gauges and a thermometer.

Definition basics to get out of the way:

Water boils at 212F at one atmosphere of pressure.

The heated-boiling pan of water stays at that temperature only the
vapor/gas can be brought above that 212F so water vapor/gas at 220F
(and one atmosphere pressure) is super-heated 8F.

Sub cooling: Water at 200F is 12F subcooled (at one atmosphere
pressure). Different pressures, different boiling points, different
numbers.

To measure SH and SC you got to know (what the liquid really is and
so its characteristic boiling points, at what pressures and also the
existing/measured temperatures and pressures.

With that, we are getting dangerously close to my limit of knowledge
on the subject. (assuming I even got it worded right)

Alvin in AZ
ps- where you at cowboy?
pps- my first post here on a.h.r!

Subject: Suction in retard, Liquid at 175.
Hmmm my guess... OP, those reading were taken with the unit not
running... and if it has pure R-22 in it, the temperature of the
equipment that day was about 95F, is that right?

Got that info from the "vapor pressure scale" on my gauge set.

c From: "cowboy"
c there is no other way to accurately determine the correct charge,
c other than weighing it in, no matter what any contractor might
c incorrectly tell you.

BTW, looking in at the label that came with my system... they left
the "total charge" area blank! :/ The system was sold without the
evaporator which varied with what would fit into my furnace?
I guess.

Actually there is a way to check the charge properly. depending on
the metering device superheat or subcoooling. weighing the charge
in is a start but you should always check with the proper method
above to insure that you are correct.

Yeah cowboy, what HvacTech2 said. :/

I'm still in the process of getting a handle on this super-heating
and sub-cooling thing myself. It's kind of tricky but is "the way"
the engineers figured out what the charge weight should be to start
with. First things first. Know what I mean, Verne?
snip
Alvin in AZ
ps- where you at cowboy?

Hey cowboy, I think I've got a handle on it now but while reading
different sources they have different temperature ranges as to being
the "best". Still learning.

This is my guess at this time...

For capillary tube type metering use the "super heat" readings.
For those with expansion valves use the "sub cooling" readings.

Ok, so you got it up and running with your gauges on it etc.
If it's R-22 with capillary metering look at the low side and read
off the number on the R-22 vapor pressure scale. Subtract that
number from the actual temperature of the suction line (at the
compressor). That's the "super heat" reading.

Using that information and looking at the table that came with my
cap-tubed Rheem they want ~20F of super heat.

Ok, so again you got it up and running with your gauges on it etc.
This time it's R-12 with an expansion valve metering, look at the
high side and read the R-12 vapor pressure scale number and subtract
that number from the actual temeperature of the condenser's exit
line (can be read at either end). That's your "sub cooling"
reading.

Ok, at least that's my understanding so far.
What I want to know is how close to right is that?

Hey! I've only been working on this for a friggin week. :/

I don't really know **** about it. :/

HvacTech2?

What have I got wrong there?

Alvin in AZ

Why don't you take an amperage reading of the compressor while it is
running and compare to the rating plate. If reed valves are shot you
should be getting a pretty low number, as the compressor is not working
very hard. High suction and Low Discharge are a good sign of a bad
compressor. Of course you could sink hundreds of dollars into fixing a
problem whereas that couple hundred dollars could go to a new
condensor. Sometimes you just have to look at how old the unit is to
determine it's time to put it out of it's misery. Also make sure filter
is clean, and inspect evap in plenum to make sure it is clear of dog
hair, dust or anything blocking air flow.

Ray T wrote:
Why don't you take an amperage reading of the compressor while it is
running and compare to the rating plate. If reed valves are shot you
should be getting a pretty low number, as the compressor is not working
very hard. High suction and Low Discharge are a good sign of a bad
compressor.

Yeah but.

He's never got back and told us that when he took those readings
the sucker was actually running.

Look at the post again? I see it as... it wasn't running and the
temperature was 95F (if it's pure R-22 .

Also make sure filter is clean, and inspect evap in plenum to make
sure it is clear of dog hair, dust or anything blocking air flow.

For sure, always the first things to do, the obvious and easy little
things.

"when you don't know what's wrong, first, before you figure it's
something big or complicated, -make all the little things right-
then see where you are" -Jack Duncan RR signal maintainer

What I'd like to see is his pressure readings with the thing running
this time? Also the temperature of the suction line at the
compressor and the temperature of the line exiting the condenser.

Alvin in AZ