Greetings,

An AC man came out checked my system a few days ago and I was told
that I needed a bigger compressor/furnace.

Basically, it was 85 or so outside and 80 inside and no hope of
getting any cooler inside. Compressor output air temp was 99 with the
coil's input at 91. The compressor has a deck over it (was like that
when I moved there). There is 3 feet above the deck. He checked the
charge and said it was good.

Inside supply air was 70 degrees. Surface mount attic fan had stopped,
so the attic was 150 or so. The fan's bad so I'll replace it today.

Anyway all that to say, the AC guy told me that I needed to go with a
5 ton unit for my 1800 square foor home. I have a 3 ton unit now. It's
a Trane and the house is 21 years old.

On 22 May 2004 03:17:56 -0700, (unix-freak)
wrote:

Greetings,

An AC man came out checked my system a few days ago and I was told
that I needed a bigger compressor/furnace.

Basically, it was 85 or so outside and 80 inside and no hope of
getting any cooler inside. Compressor output air temp was 99 with the
coil's input at 91. The compressor has a deck over it (was like that
when I moved there). There is 3 feet above the deck. He checked the
charge and said it was good.

Inside supply air was 70 degrees. Surface mount attic fan had stopped,
so the attic was 150 or so. The fan's bad so I'll replace it today.

Anyway all that to say, the AC guy told me that I needed to go with a
5 ton unit for my 1800 square foor home. I have a 3 ton unit now. It's

a Trane and the house is 21 years old.

Location? I'd guess that 3 would be adequate in the midwest; I have a
house that is 1700 and 2.5 does it fairly well in central MO. If you
put in a unit that large, I'd bet they'd have to do a ton of duct work
because what you have likely isn't adequate for that size of system.
I'd call another contractor, and if they recommend up-sizing ask them
to show you the manual j.

On 22 May 2004 03:17:56 -0700, (unix-freak)
wrote:

Basically, it was 85 or so outside and 80 inside and no hope of
getting any cooler inside. Compressor output air temp was 99 with the
coil's input at 91.

Pardon me, but what are you trying to say? Are you measuring the temp
of the condensor cooling fan air or what? The important temp is the
air coming off the evaporator coil into your ductwork - what is that
value?

There is 3 feet above the deck. He checked the
charge and said it was good.

What were the pressures measured at the compressor? You can have
plenty of freon and the system still may not work if you have a
plugged expansion valve or other easy-to-fix problem.

Inside supply air was 70 degrees.

Air coming out of the registers?

Surface mount attic fan had stopped,
so the attic was 150 or so. The fan's bad so I'll replace it today.

150 in the attic? No wonder your house is warm inside. Get some
adequate ventialtion and fix that vent fan and then see how your
system does.

Anyway all that to say, the AC guy told me that I needed to go with a
5 ton unit for my 1800 square foor home. I have a 3 ton unit now. It's
a Trane and the house is 21 years old.

I live in a hot (not blistering) climate in Eastern Washington. My a/c
is a 5 ton, but I have 4500 sq ft. Unless you live in the SW desert I
don't see how you need a 5T unit in an 1800 sq ft house. I second the
comment that your duct system won't work if you double the size of the
a/c and air handler.

Talk to at least two more reliable contractors before acting. And get
that attic temp down first.



John Davies
http://home.comcast.net/~johnedavies/
'96 Lexus LX450
'00 Audi A4 1.8T quattro
Spokane WA USA

I'm located in Georgia, where it is warm and humid.


Chris Hill wrote in message . ..
On 22 May 2004 03:17:56 -0700, (unix-freak)
wrote:

Greetings,

An AC man came out checked my system a few days ago and I was told
that I needed a bigger compressor/furnace.

Basically, it was 85 or so outside and 80 inside and no hope of
getting any cooler inside. Compressor output air temp was 99 with the
coil's input at 91. The compressor has a deck over it (was like that
when I moved there). There is 3 feet above the deck. He checked the
charge and said it was good.

Inside supply air was 70 degrees. Surface mount attic fan had stopped,
so the attic was 150 or so. The fan's bad so I'll replace it today.

Anyway all that to say, the AC guy told me that I needed to go with a
5 ton unit for my 1800 square foor home. I have a 3 ton unit now. It's

a Trane and the house is 21 years old.

Location? I'd guess that 3 would be adequate in the midwest; I have a
house that is 1700 and 2.5 does it fairly well in central MO. If you
put in a unit that large, I'd bet they'd have to do a ton of duct work
because what you have likely isn't adequate for that size of system.
I'd call another contractor, and if they recommend up-sizing ask them
to show you the manual j.

"John Davies" wrote in message
...
On 22 May 2004 03:17:56 -0700, (unix-freak)
wrote:

Basically, it was 85 or so outside and 80 inside and no hope of
getting any cooler inside. Compressor output air temp was 99 with the
coil's input at 91.

Pardon me, but what are you trying to say? Are you measuring the temp
of the condensor cooling fan air or what? The important temp is the
air coming off the evaporator coil into your ductwork - what is that
value?

Yes. The air temp was measured at the compressor just to see if there was
too much air getting trapped under the deck.

A couple of days ago it was 80 outside. I measured 78 into the condensor
coil and at the plenum after the coil was 68.


There is 3 feet above the deck. He checked the
charge and said it was good.

What were the pressures measured at the compressor? You can have
plenty of freon and the system still may not work if you have a
plugged expansion valve or other easy-to-fix problem.


I don't remember. I think the high side was at 200 lbs.

Inside supply air was 70 degrees.

Air coming out of the registers?
Yes.


Surface mount attic fan had stopped,
so the attic was 150 or so. The fan's bad so I'll replace it today.

150 in the attic? No wonder your house is warm inside. Get some
adequate ventialtion and fix that vent fan and then see how your
system does.


I just replaced the fan an hour ago.

Anyway all that to say, the AC guy told me that I needed to go with a
5 ton unit for my 1800 square foor home. I have a 3 ton unit now. It's
a Trane and the house is 21 years old.

I live in a hot (not blistering) climate in Eastern Washington. My a/c
is a 5 ton, but I have 4500 sq ft. Unless you live in the SW desert I
don't see how you need a 5T unit in an 1800 sq ft house. I second the
comment that your duct system won't work if you double the size of the
a/c and air handler.

Talk to at least two more reliable contractors before acting. And get
that attic temp down first.



John Davies
http://home.comcast.net/~johnedavies/
'96 Lexus LX450
'00 Audi A4 1.8T quattro
Spokane WA USA

unix-freak wrote:
Greetings,

An AC man came out checked my system a few days ago and I was told
that I needed a bigger compressor/furnace.

Basically, it was 85 or so outside and 80 inside and no hope of
getting any cooler inside. Compressor output air temp was 99 with the
coil's input at 91. The compressor has a deck over it (was like that
when I moved there). There is 3 feet above the deck. He checked the
charge and said it was good.

Inside supply air was 70 degrees. Surface mount attic fan had stopped,
so the attic was 150 or so. The fan's bad so I'll replace it today.

Anyway all that to say, the AC guy told me that I needed to go with a
5 ton unit for my 1800 square foor home. I have a 3 ton unit now. It's
a Trane and the house is 21 years old.

What did his Manual J heat gain / loss calculations show that you need?
He DID do a Manual J, right? If not, call another contractor.

What is the return air temperature measured at the registers?
What is the return air temperature measured at the air handler plenum
(return side)?
If there is more than 2 degrees difference between the above two
readings you either have a leak or inadequate insulation on the return
ducting.

What is the supply air temperature measured at the air handler plenum
(supply side)?
Subtract the last two - What is the delta-T (temperature drop across the
air handler)? Should be 17 - 22 degrees. If it is outside this range
then I'd call another contractor.

"Travis Jordan" wrote in message
m...
unix-freak wrote:
Greetings,

An AC man came out checked my system a few days ago and I was told
that I needed a bigger compressor/furnace.

Basically, it was 85 or so outside and 80 inside and no hope of
getting any cooler inside. Compressor output air temp was 99 with the
coil's input at 91. The compressor has a deck over it (was like that
when I moved there). There is 3 feet above the deck. He checked the
charge and said it was good.

Inside supply air was 70 degrees. Surface mount attic fan had stopped,
so the attic was 150 or so. The fan's bad so I'll replace it today.

Anyway all that to say, the AC guy told me that I needed to go with a
5 ton unit for my 1800 square foot home. I have a 3 ton unit now. It's
a Trane and the house is 21 years old.

What did his Manual J heat gain / loss calculations show that you need?
He DID do a Manual J, right? If not, call another contractor.

Not sure.

What is the return air temperature measured at the registers?

76
What is the return air temperature measured at the air handler plenum
(return side)?

78
If there is more than 2 degrees difference between the above two
readings you either have a leak or inadequate insulation on the return
ducting.

What is the supply air temperature measured at the air handler plenum
(supply side)?

68
Subtract the last two - What is the delta-T (temperature drop across the
air handler)? Should be 17 - 22 degrees. If it is outside this range
then I'd call another contractor.

Somethings not right. There's not much condensation from the condensor coil
either. Maybe I need to get in there and clean it.

unix-freak wrote:
"Travis Jordan" wrote in message
m...
unix-freak wrote:
Greetings,

An AC man came out checked my system a few days ago and I was told
that I needed a bigger compressor/furnace.

Basically, it was 85 or so outside and 80 inside and no hope of
getting any cooler inside. Compressor output air temp was 99 with
the coil's input at 91. The compressor has a deck over it (was like
that when I moved there). There is 3 feet above the deck. He
checked the charge and said it was good.

Inside supply air was 70 degrees. Surface mount attic fan had
stopped, so the attic was 150 or so. The fan's bad so I'll replace
it today.

Anyway all that to say, the AC guy told me that I needed to go with
a 5 ton unit for my 1800 square foot home. I have a 3 ton unit now.
It's a Trane and the house is 21 years old.

What did his Manual J heat gain / loss calculations show that you
need? He DID do a Manual J, right? If not, call another contractor.

Not sure.

What is the return air temperature measured at the registers?

76
What is the return air temperature measured at the air handler plenum
(return side)?

78
If there is more than 2 degrees difference between the above two
readings you either have a leak or inadequate insulation on the
return ducting.

What is the supply air temperature measured at the air handler plenum
(supply side)?

68
Subtract the last two - What is the delta-T (temperature drop across
the air handler)? Should be 17 - 22 degrees. If it is outside this
range then I'd call another contractor.

Somethings not right. There's not much condensation from the
condensor coil either. Maybe I need to get in there and clean it.

I assume you mean "There's not much condensation from the evaporator
(inside) coil..."

The most common causes of low delta-T a

1) undercharged refrigerant due to a leak
2) excessive air flow over evaporator (i.e.air handler fan set to wrong
speed)
3) dirty condenser coil

There are other less-common things that go wrong such as problems with
the thermal expansion valve (TXV), bad compressor valves, bad reversing
valve, and more. About the only thing you can do as a homeowner is
check the outside coil to make sure it is clean. If it is, you really
need to call a qualified serviceperson (I would submit that the one you
called last time who recommended a larger unit is not among the list of
service people to talk to).

Please post back when you have a final resolution.

I assume you mean "There's not much condensation from the evaporator
(inside) coil..."

Yeah...that's what I meant. I actually opened up the plenum and there's
plenty of water. I didn't do anything as far as coil cleaning. I guess I
could spray it down with the proper coil cleaner. I also made sure that the
PVC wasn't clogged while I was there.

The most common causes of low delta-T a

1) undercharged refrigerant due to a leak
I had a different tech out last summer and he said that the charge was fine,
so that's 2 techs that have had their guages on it saying it's fine.


2) excessive air flow over evaporator (i.e.air handler fan set to wrong
speed)
I double checked it, and it's wired for high with the heater wired for low.

3) dirty condenser coil

There are other less-common things that go wrong such as problems with
the thermal expansion valve (TXV), bad compressor valves, bad reversing
valve, and more. About the only thing you can do as a homeowner is
check the outside coil to make sure it is clean. If it is, you really
need to call a qualified serviceperson (I would submit that the one you
called last time who recommended a larger unit is not among the list of
service people to talk to).

Please post back when you have a final resolution.

Oh...one more thing. It's 88 outside right now and my compressor just cut
off on it's own even though the fan is still running and the thermostat set
to auto. It did that yesterday and I had to turn off power to it for 10
minutes, then it came back after that. I know in automotive ac, the clutch
with kick off if the charge is low.

unix-freak wrote:
I assume you mean "There's not much condensation from the evaporator
(inside) coil..."

Yeah...that's what I meant. I actually opened up the plenum and
there's plenty of water. I didn't do anything as far as coil
cleaning. I guess I could spray it down with the proper coil cleaner.
I also made sure that the PVC wasn't clogged while I was there.

The most common causes of low delta-T a

1) undercharged refrigerant due to a leak
I had a different tech out last summer and he said that the charge
was fine, so that's 2 techs that have had their guages on it saying
it's fine.


2) excessive air flow over evaporator (i.e.air handler fan set to
wrong speed)
I double checked it, and it's wired for high with the heater wired
for low.

3) dirty condenser coil

There are other less-common things that go wrong such as problems
with the thermal expansion valve (TXV), bad compressor valves, bad
reversing valve, and more. About the only thing you can do as a
homeowner is check the outside coil to make sure it is clean. If it
is, you really need to call a qualified serviceperson (I would
submit that the one you called last time who recommended a larger
unit is not among the list of service people to talk to).

Please post back when you have a final resolution.

Oh...one more thing. It's 88 outside right now and my compressor just
cut off on it's own even though the fan is still running and the
thermostat set to auto. It did that yesterday and I had to turn off
power to it for 10 minutes, then it came back after that. I know in
automotive ac, the clutch with kick off if the charge is low.

It is also possible that the compressor is overheating and shutting down
on overtemperature. If the system were just low on refrigerant (and it
had an auto-reset low-pressure switch installed, a feature seen mostly
on high-end systems) then indeed it might restart after 10 minutes. How
ever, I wouldn't risk compressor damage if I were you.

Tomorrow morning call one of the local HVAC distributors and ask the
counter person for the name of a really good technician that they would
have work on their personal system. Johnstone Supply will do if you
have one in the area, or find the distributor for the manufacturer of
your system.

It is also possible that the compressor is overheating and shutting down
on overtemperature. If the system were just low on refrigerant (and it
had an auto-reset low-pressure switch installed, a feature seen mostly
on high-end systems) then indeed it might restart after 10 minutes. How
ever, I wouldn't risk compressor damage if I were you.

Tomorrow morning call one of the local HVAC distributors and ask the
counter person for the name of a really good technician that they would
have work on their personal system. Johnstone Supply will do if you
have one in the area, or find the distributor for the manufacturer of
your system.

OK..I've got a guy coming out on Friday to check it out. To tell you
the truth, I think it was already low on freon when the other guy was
out last Thursday and when he disconnected his guages, he didn't do it
quick enough as freon came pouring out on the high side. I didn't
have the compressor cutting off problem prior to this. The fan still
runs at the blower and compressor so I don't suspect that there's
anything wrong with the thermostat.

unix-freak wrote:
It is also possible that the compressor is overheating and shutting
down on overtemperature. If the system were just low on
refrigerant (and it had an auto-reset low-pressure switch installed,
a feature seen mostly on high-end systems) then indeed it might
restart after 10 minutes. How ever, I wouldn't risk compressor
damage if I were you.

Tomorrow morning call one of the local HVAC distributors and ask the
counter person for the name of a really good technician that they
would have work on their personal system. Johnstone Supply will do
if you have one in the area, or find the distributor for the
manufacturer of your system.

OK..I've got a guy coming out on Friday to check it out. To tell you
the truth, I think it was already low on freon when the other guy was
out last Thursday and when he disconnected his guages, he didn't do it
quick enough as freon came pouring out on the high side. I didn't
have the compressor cutting off problem prior to this. The fan still
runs at the blower and compressor so I don't suspect that there's
anything wrong with the thermostat.

Let's hope he is a tech who understands the mechanics of the
refrigeration cycle and that he isn't just a 'parts changer'. I
encourage you to ask him how he plans to diagnose your system's
performance. Here's some background reading so you can be prepared to
have a knowledgeable discussion.

http://hvac-talk.com/vbb/showthread.php?threadid=33829
http://www.hvacloads.com/talkpdf/charge.pdf
http://www.hvacloads.com/talkpdf/tro..._superheat.pdf

Travis Jordan wrote:
unix-freak wrote:
It is also possible that the compressor is overheating and shutting
down on overtemperature. If the system were just low on
refrigerant (and it had an auto-reset low-pressure switch installed,
a feature seen mostly on high-end systems) then indeed it might
restart after 10 minutes. How ever, I wouldn't risk compressor
damage if I were you.

Tomorrow morning call one of the local HVAC distributors and ask the
counter person for the name of a really good technician that they
would have work on their personal system. Johnstone Supply will do
if you have one in the area, or find the distributor for the
manufacturer of your system.

OK..I've got a guy coming out on Friday to check it out. To tell you
the truth, I think it was already low on freon when the other guy was
out last Thursday and when he disconnected his guages, he didn't do
it quick enough as freon came pouring out on the high side. I
didn't have the compressor cutting off problem prior to this. The
fan still runs at the blower and compressor so I don't suspect that
there's anything wrong with the thermostat.

Let's hope he is a tech who understands the mechanics of the
refrigeration cycle and that he isn't just a 'parts changer'. I
encourage you to ask him how he plans to diagnose your system's
performance. Here's some background reading so you can be prepared to
have a knowledgeable discussion.

http://hvac-talk.com/vbb/showthread.php?threadid=33829
http://www.hvacloads.com/talkpdf/charge.pdf
http://www.hvacloads.com/talkpdf/tro..._superheat.pdf

One more thing; you may want to do a Manual J (heat gain / loss)
calculation to see what your system size should be. This is the only
reliable way to figure out what BTU (ton) rating you need for adequate
cooling and heating. I've had good luck with the (old) Lennox Load
Calculation software, available for free download at
http://home.att.net/~alt.hvac/loads.htm

"Travis Jordan" wrote in message om...
Travis Jordan wrote:
unix-freak wrote:
It is also possible that the compressor is overheating and shutting
down on overtemperature. If the system were just low on
refrigerant (and it had an auto-reset low-pressure switch installed,
a feature seen mostly on high-end systems) then indeed it might
restart after 10 minutes. How ever, I wouldn't risk compressor
damage if I were you.

Tomorrow morning call one of the local HVAC distributors and ask the
counter person for the name of a really good technician that they
would have work on their personal system. Johnstone Supply will do
if you have one in the area, or find the distributor for the
manufacturer of your system.

OK..I've got a guy coming out on Friday to check it out. To tell you
the truth, I think it was already low on freon when the other guy was
out last Thursday and when he disconnected his guages, he didn't do
it quick enough as freon came pouring out on the high side. I
didn't have the compressor cutting off problem prior to this. The
fan still runs at the blower and compressor so I don't suspect that
there's anything wrong with the thermostat.

Let's hope he is a tech who understands the mechanics of the
refrigeration cycle and that he isn't just a 'parts changer'. I
encourage you to ask him how he plans to diagnose your system's
performance. Here's some background reading so you can be prepared to
have a knowledgeable discussion.

http://hvac-talk.com/vbb/showthread.php?threadid=33829
http://www.hvacloads.com/talkpdf/charge.pdf
http://www.hvacloads.com/talkpdf/tro..._superheat.pdf

One more thing; you may want to do a Manual J (heat gain / loss)
calculation to see what your system size should be. This is the only
reliable way to figure out what BTU (ton) rating you need for adequate
cooling and heating. I've had good luck with the (old) Lennox Load
Calculation software, available for free download at
http://home.att.net/~alt.hvac/loads.htm

Very cool. Thanks for the advice and resources.
You can't be to careful. I trust very few when it comes to certain
things such as this. That's why I do all of my own auto repairs, home
repairs....electrical....and the list goes on. Unfortunatley I won't
be there when he's there Friday morning. My wife referred me to this
company because her mother uses them and she's gotten good results
with them.

OK.... I checked the run capacitor and it measured 35uF; well within 10%
tolerance. My AC guy called me back and came by and found that the system
was 2 lbs low on freon. After charging it, it's run fine since 5:30 and the
compressor has NOT cut off. It was 84 in the house and 5 hours later is down
to 78. When he was here he measured the return air at 81 and the supply at
68 at the registers. Tomorrow when I go to work I'll just cut it down to 76
and see if the house is cool when I get home.



"unix-freak" wrote in message
om...
"Travis Jordan" wrote in message
om...
Travis Jordan wrote:
unix-freak wrote:
It is also possible that the compressor is overheating and shutting
down on overtemperature. If the system were just low on
refrigerant (and it had an auto-reset low-pressure switch installed,
a feature seen mostly on high-end systems) then indeed it might
restart after 10 minutes. How ever, I wouldn't risk compressor
damage if I were you.

Tomorrow morning call one of the local HVAC distributors and ask the
counter person for the name of a really good technician that they
would have work on their personal system. Johnstone Supply will do
if you have one in the area, or find the distributor for the
manufacturer of your system.

OK..I've got a guy coming out on Friday to check it out. To tell you
the truth, I think it was already low on freon when the other guy was
out last Thursday and when he disconnected his guages, he didn't do
it quick enough as freon came pouring out on the high side. I
didn't have the compressor cutting off problem prior to this. The
fan still runs at the blower and compressor so I don't suspect that
there's anything wrong with the thermostat.

Let's hope he is a tech who understands the mechanics of the
refrigeration cycle and that he isn't just a 'parts changer'. I
encourage you to ask him how he plans to diagnose your system's
performance. Here's some background reading so you can be prepared to
have a knowledgeable discussion.

http://hvac-talk.com/vbb/showthread.php?threadid=33829
http://www.hvacloads.com/talkpdf/charge.pdf
http://www.hvacloads.com/talkpdf/tro..._superheat.pdf

One more thing; you may want to do a Manual J (heat gain / loss)
calculation to see what your system size should be. This is the only
reliable way to figure out what BTU (ton) rating you need for adequate
cooling and heating. I've had good luck with the (old) Lennox Load
Calculation software, available for free download at
http://home.att.net/~alt.hvac/loads.htm

Very cool. Thanks for the advice and resources.
You can't be to careful. I trust very few when it comes to certain
things such as this. That's why I do all of my own auto repairs, home
repairs....electrical....and the list goes on. Unfortunatley I won't
be there when he's there Friday morning. My wife referred me to this
company because her mother uses them and she's gotten good results
with them.

unix-freak wrote:
OK.... I checked the run capacitor and it measured 35uF; well within
10% tolerance. My AC guy called me back and came by and found that
the system was 2 lbs low on freon. After charging it, it's run fine
since 5:30 and the compressor has NOT cut off. It was 84 in the house
and 5 hours later is down to 78. When he was here he measured the
return air at 81 and the supply at 68 at the registers. Tomorrow when
I go to work I'll just cut it down to 76 and see if the house is cool
when I get home.

The 13 degree drop across the air handler is low - as I said earlier it
should be 17 - 22. What did he say about the root cause of that part of
the problem?

How did he know you were two pounds low? What method did he use to
charge the system?

If you are / were low on refrigerant (Freon is a trademark for one
manufacturer's blend of R-22) then you need to find out where it is
leaking. Did the tech do a leak test?

My guess is that your system will run for a while and then you'll be
back in the same inadequate cooling situation. So then what?

"Travis Jordan" wrote in message
...
unix-freak wrote:
OK.... I checked the run capacitor and it measured 35uF; well within
10% tolerance. My AC guy called me back and came by and found that
the system was 2 lbs low on freon. After charging it, it's run fine
since 5:30 and the compressor has NOT cut off. It was 84 in the house
and 5 hours later is down to 78. When he was here he measured the
return air at 81 and the supply at 68 at the registers. Tomorrow when
I go to work I'll just cut it down to 76 and see if the house is cool
when I get home.

The 13 degree drop across the air handler is low - as I said earlier it
should be 17 - 22. What did he say about the root cause of that part of
the problem?

He said 13 degrees was good.

How did he know you were two pounds low? What method did he use to
charge the system?

R-22 / guages.

If you are / were low on refrigerant (Freon is a trademark for one
manufacturer's blend of R-22) then you need to find out where it is
leaking. Did the tech do a leak test?

Not sure.

My guess is that your system will run for a while and then you'll be
back in the same inadequate cooling situation. So then what?

I don't know. It's conceivable that the first guy leaked a bunch of R-22 out
when he was disconnecting his guages.

unix-freak wrote:
"Travis Jordan" wrote in message
...
unix-freak wrote:
OK.... I checked the run capacitor and it measured 35uF; well within
10% tolerance. My AC guy called me back and came by and found that
the system was 2 lbs low on freon. After charging it, it's run fine
since 5:30 and the compressor has NOT cut off. It was 84 in the
house and 5 hours later is down to 78. When he was here he measured
the return air at 81 and the supply at 68 at the registers.
Tomorrow when I go to work I'll just cut it down to 76 and see if
the house is cool when I get home.

The 13 degree drop across the air handler is low - as I said earlier
it should be 17 - 22. What did he say about the root cause of that
part of the problem?

He said 13 degrees was good.

How did he know you were two pounds low? What method did he use to
charge the system?

R-22 / guages.

If you are / were low on refrigerant (Freon is a trademark for one
manufacturer's blend of R-22) then you need to find out where it is
leaking. Did the tech do a leak test?

Not sure.

My guess is that your system will run for a while and then you'll be
back in the same inadequate cooling situation. So then what?

I don't know. It's conceivable that the first guy leaked a bunch of
R-22 out when he was disconnecting his guages.

Not 2 lbs worth! That is a LOT of R-22 in vapor form.

A competent tech would never add R-22 without also looking for a leak.
In a closed system refrigerant doesn't get "used up". I'd call the
contractor back and ask them whether they did a leak test, and if not,
why not.

Travis Jordan wrote:
unix-freak wrote:
"Travis Jordan" wrote in message
...
unix-freak wrote:
OK.... I checked the run capacitor and it measured 35uF; well
within 10% tolerance. My AC guy called me back and came by and
found that the system was 2 lbs low on freon. After charging it,
it's run fine since 5:30 and the compressor has NOT cut off. It
was 84 in the house and 5 hours later is down to 78. When he was
here he measured the return air at 81 and the supply at 68 at the
registers. Tomorrow when I go to work I'll just cut it down to 76
and see if the house is cool when I get home.

The 13 degree drop across the air handler is low - as I said earlier
it should be 17 - 22. What did he say about the root cause of that
part of the problem?

He said 13 degrees was good.

How did he know you were two pounds low? What method did he use to
charge the system?

R-22 / guages.

If you are / were low on refrigerant (Freon is a trademark for one
manufacturer's blend of R-22) then you need to find out where it is
leaking. Did the tech do a leak test?

Not sure.

My guess is that your system will run for a while and then you'll be
back in the same inadequate cooling situation. So then what?

I don't know. It's conceivable that the first guy leaked a bunch of
R-22 out when he was disconnecting his guages.

Not 2 lbs worth! That is a LOT of R-22 in vapor form.

A competent tech would never add R-22 without also looking for a leak.
In a closed system refrigerant doesn't get "used up". I'd call the
contractor back and ask them whether they did a leak test, and if not,
why not.

Forgot to include this on charging methods - gauges alone won't do it.
http://wwwebworks.com/ht/fyi/Jim_Wheeler_Charging.htm

On 22 May 2004 03:17:56 -0700, (unix-freak)
wrote:

An AC man came out checked my system a few days ago and I was told
that I needed a bigger compressor/furnace.

Anyway all that to say, the AC guy told me that I needed to go with a
5 ton unit for my 1800 square foor home. I have a 3 ton unit now. It's
a Trane and the house is 21 years old.

Trying to diagnose a problem like this on the Internet is not the
solution because of so many variables and lack of details. The best
way I can help you is to direct you to competant service. Just
mentioning that you have a Trane unit, I suggest that you visit their
website to locate a Comfort Specialist dealer. Go to www.trane.com
and under the residential section, look for the dealer locator. You
will come up with a list of dealers and some of them should be labeled
as a Comfort Specialist dealer. I suggest you call those. If you
have several to choose from, you might ask each if they have any NATE
certified technicians. Not necessary but is a sign they might be
better technically.

If you don't use a Trane dealer, check the sites of other brands on
the internet to locate their premier dealers. You will pay more money
for a good dealer but doing air conditioning correctly will cost
less in the long run.

"Travis Jordan" wrote in message om...
Travis Jordan wrote:
unix-freak wrote:
"Travis Jordan" wrote in message
...
unix-freak wrote:
OK.... I checked the run capacitor and it measured 35uF; well
within 10% tolerance. My AC guy called me back and came by and
found that the system was 2 lbs low on freon. After charging it,
it's run fine since 5:30 and the compressor has NOT cut off. It
was 84 in the house and 5 hours later is down to 78. When he was
here he measured the return air at 81 and the supply at 68 at the
registers. Tomorrow when I go to work I'll just cut it down to 76
and see if the house is cool when I get home.

The 13 degree drop across the air handler is low - as I said earlier
it should be 17 - 22. What did he say about the root cause of that
part of the problem?

He said 13 degrees was good.

How did he know you were two pounds low? What method did he use to
charge the system?

R-22 / guages.

If you are / were low on refrigerant (Freon is a trademark for one
manufacturer's blend of R-22) then you need to find out where it is
leaking. Did the tech do a leak test?

Not sure.

My guess is that your system will run for a while and then you'll be
back in the same inadequate cooling situation. So then what?

I don't know. It's conceivable that the first guy leaked a bunch of
R-22 out when he was disconnecting his guages.

Not 2 lbs worth! That is a LOT of R-22 in vapor form.

A competent tech would never add R-22 without also looking for a leak.
In a closed system refrigerant doesn't get "used up". I'd call the
contractor back and ask them whether they did a leak test, and if not,
why not.

Forgot to include this on charging methods - gauges alone won't do it.
http://wwwebworks.com/ht/fyi/Jim_Wheeler_Charging.htm

The whole thing is pretty discouraging. I've spent 170.00 between 2
techs and am right back where I started. The first guy I paid 75.00
for what...to leak out a bunch of r-22? The second guy at least got it
charged back up. I just need to find someone that will come out and
look at things from an engineering aspect and really assess what's
going on. IMO, if an AC system has a 13 degree differential across the
evaporatorm then the tech should know where to look, not just leave
and collect his 92.00, saying that 13 degrees is good.

Assuming that the charge is good, and there's only a 13 degree
difference across the coil, maybe it just needs cleaning. I would
think that if it were dirty on the bottom, that it would be freezing
up.

unix-freak wrote:
"Travis Jordan" wrote in message
om...
Travis Jordan wrote:
unix-freak wrote:
"Travis Jordan" wrote in message
...
unix-freak wrote:
OK.... I checked the run capacitor and it measured 35uF; well
within 10% tolerance. My AC guy called me back and came by and
found that the system was 2 lbs low on freon. After charging it,
it's run fine since 5:30 and the compressor has NOT cut off. It
was 84 in the house and 5 hours later is down to 78. When he was
here he measured the return air at 81 and the supply at 68 at the
registers. Tomorrow when I go to work I'll just cut it down to 76
and see if the house is cool when I get home.

The 13 degree drop across the air handler is low - as I said
earlier it should be 17 - 22. What did he say about the root
cause of that part of the problem?

He said 13 degrees was good.

How did he know you were two pounds low? What method did he use
to charge the system?

R-22 / guages.

If you are / were low on refrigerant (Freon is a trademark for one
manufacturer's blend of R-22) then you need to find out where it
is leaking. Did the tech do a leak test?

Not sure.

My guess is that your system will run for a while and then you'll
be back in the same inadequate cooling situation. So then what?

I don't know. It's conceivable that the first guy leaked a bunch of
R-22 out when he was disconnecting his guages.

Not 2 lbs worth! That is a LOT of R-22 in vapor form.

A competent tech would never add R-22 without also looking for a
leak. In a closed system refrigerant doesn't get "used up". I'd
call the contractor back and ask them whether they did a leak test,
and if not, why not.

Forgot to include this on charging methods - gauges alone won't do
it. http://wwwebworks.com/ht/fyi/Jim_Wheeler_Charging.htm

The whole thing is pretty discouraging. I've spent 170.00 between 2
techs and am right back where I started. The first guy I paid 75.00
for what...to leak out a bunch of r-22? The second guy at least got it
charged back up. I just need to find someone that will come out and
look at things from an engineering aspect and really assess what's
going on. IMO, if an AC system has a 13 degree differential across the
evaporatorm then the tech should know where to look, not just leave
and collect his 92.00, saying that 13 degrees is good.

Assuming that the charge is good, and there's only a 13 degree
difference across the coil, maybe it just needs cleaning. I would
think that if it were dirty on the bottom, that it would be freezing
up.

I think Steve Bukosky's advice is pretty good - another option is to
call the local Trane distributor and ask them who THEY would have work
on their home system.

Steve Bukosky wrote:

Trying to diagnose a problem like this on the Internet is not the
solution because of so many variables and lack of details. The best
way I can help you is to direct you to competant service. Just
mentioning that you have a Trane unit, I suggest that you visit their
website to locate a Comfort Specialist dealer. Go to www.trane.com
and under the residential section, look for the dealer locator. You
will come up with a list of dealers and some of them should be labeled
as a Comfort Specialist dealer. I suggest you call those. If you
have several to choose from, you might ask each if they have any NATE
certified technicians. Not necessary but is a sign they might be
better technically.

If you don't use a Trane dealer, check the sites of other brands on
the internet to locate their premier dealers. You will pay more money
for a good dealer but doing air conditioning correctly will cost
less in the long run.

If you don't use a Trane dealer, check the sites of other brands on
the internet to locate their premier dealers. You will pay more money
for a good dealer but doing air conditioning correctly will cost
less in the long run.

I forgot to mention that the condensing unit is under a deck with 3
feet of clearance above it. I've heard from some that it's ok, and
from others that it's not.

unix-freak wrote:
I forgot to mention that the condensing unit is under a deck with 3
feet of clearance above it. I've heard from some that it's ok, and
from others that it's not.

Trane's installation guide for their current upflow models (XB10,
XB1000, XR12) says you need 5 feet unrestricted above the top of the
unit. Of course this doesn't apply to the side-exhaust models. Since
yours is an older unit it is probably top exhaust and therefore the 5
feet recommendation probably applies.

Wheter that is the cause of your low drop across the evaporator or
whether it is something else (like a restriction in the liquid line, bad
compressor valves, etc.) we can't tell from here.

Hi Travis,

What's a fair price to move the condensing unit out from under the deck?
There's plenty of service to make the trip.


"Travis Jordan" wrote in message
om...
unix-freak wrote:
I forgot to mention that the condensing unit is under a deck with 3
feet of clearance above it. I've heard from some that it's ok, and
from others that it's not.

Trane's installation guide for their current upflow models (XB10,
XB1000, XR12) says you need 5 feet unrestricted above the top of the
unit. Of course this doesn't apply to the side-exhaust models. Since
yours is an older unit it is probably top exhaust and therefore the 5
feet recommendation probably applies.

Wheter that is the cause of your low drop across the evaporator or
whether it is something else (like a restriction in the liquid line, bad
compressor valves, etc.) we can't tell from here.

unix-freak wrote:
Hi Travis,

What's a fair price to move the condensing unit out from under the
deck? There's plenty of service to make the trip.


"Travis Jordan" wrote in message
om...
unix-freak wrote:
I forgot to mention that the condensing unit is under a deck with 3
feet of clearance above it. I've heard from some that it's ok, and
from others that it's not.

Trane's installation guide for their current upflow models (XB10,
XB1000, XR12) says you need 5 feet unrestricted above the top of the
unit. Of course this doesn't apply to the side-exhaust models.
Since yours is an older unit it is probably top exhaust and
therefore the 5 feet recommendation probably applies.

Wheter that is the cause of your low drop across the evaporator or
whether it is something else (like a restriction in the liquid line,
bad compressor valves, etc.) we can't tell from here.

Hard to tell exactly, unfortunately. The system will have to be pumped
down (storing all the refrigerant in the condensor) and the lineset,
power, and air handler / thermostat wiring disconnected. You also will
need to pour or install a pre-fab pad to put the unit on, move the
disconnect (which may require an electrician...depends on local codes),
reconnect the low-voltage wiring, rebraze the lineset, evacuate the
lines and then recharge the system. Could take two or three hours,
maybe more, plus whatever parts are required.

I changed out the old mercury thermostat on Sunday, and it was reading
4 degrees low from what the new programable reads. The old read 76
while to new 80. I think it was like 84 outside and after a couple
hours the house was very cool at 75.

All that to say, is it's nice to have a handle on the "real" temp, but
will be interesting/depressing to see what the bill looks like due to
the extra on time of the condensing unit. Some of that might be offset
by the fact that I have programmed it.

Another hvac tech came out and determined that my compressor is shot. He
took the time to do the manual J, heat gain, superheat...etc. Suction press
was 80 and the liquid press was at 200 and he said that the internal valves
were bad.

He quoted me 4,000-4,800 for a 3 ton Trane (12 seer)condensing unit and
furnace. They're also gonna install the condensing unit on the side of the
house instead of under the deck, which is where mine is now.





"Travis Jordan" wrote in message
om...
unix-freak wrote:
Hi Travis,

What's a fair price to move the condensing unit out from under the
deck? There's plenty of service to make the trip.


"Travis Jordan" wrote in message
om...
unix-freak wrote:
I forgot to mention that the condensing unit is under a deck with 3
feet of clearance above it. I've heard from some that it's ok, and
from others that it's not.

Trane's installation guide for their current upflow models (XB10,
XB1000, XR12) says you need 5 feet unrestricted above the top of the
unit. Of course this doesn't apply to the side-exhaust models.
Since yours is an older unit it is probably top exhaust and
therefore the 5 feet recommendation probably applies.

Wheter that is the cause of your low drop across the evaporator or
whether it is something else (like a restriction in the liquid line,
bad compressor valves, etc.) we can't tell from here.

Hard to tell exactly, unfortunately. The system will have to be pumped
down (storing all the refrigerant in the condensor) and the lineset,
power, and air handler / thermostat wiring disconnected. You also will
need to pour or install a pre-fab pad to put the unit on, move the
disconnect (which may require an electrician...depends on local codes),
reconnect the low-voltage wiring, rebraze the lineset, evacuate the
lines and then recharge the system. Could take two or three hours,
maybe more, plus whatever parts are required.