A/C pressure question

[kenthagler]

Hi Guys, thanks for reading this. My home unit has been running from first thing in the morning to late at night. I live just North of Dallas, Tx and the temps have been over 100 for ever it seems.

I have 2 a/c units, the main unit is a 5 ton payne unit with the evaporator/furnace unit in the attic. Was originally a Carrier unit but the compressor went out so it was replaced with a Payne unit, just the compressor was replaced. We only run the down stairs unit and keep the up stairs of the house shut off, its just myself and the wife. I don't remember the unit never keeping up before, the stat is now set on 77 degrees and the room temp is always around 80. We used to keep it at 76 (and I thought it would hit 76 degrees in the daytime in the house) until I got my last bill which was $490 for the month of Sept. 2700 sq ft house with approx 800 sq ft shut off.

The other unit is a 3 ton Carrier which I only use when company comes.

Today, I measured 104 outside temp, 115 static pressure, 67 low side and 158 high side pressures. The low side line is always sweating and cool, the high side line is warm to the touch. Humidity has been between 40-50% all week.
I just looked at the temp on the stat and it now reads 80 degrees with it set at 77. My bedroom just on the other side of the wall reads 78.4 degees, master bath reads 80.4 degrees but the wife just got out of the shower :)

Do the pressures sound right? About 2 months ago I had a service call and the guy dug up the a/c lines that came out of the house and went underground for about 6 feet before they connected to the unit, the unit was liquid sludging on start up at times, ( figured that is what caused the original unit to fail) he also install a TXV (he called it a hard stop) at the evaporator unit. Since it seems like it just doesn't cool like it used to and my bill has been more than ever before, It may just be the 40 days we have had this summer with the temp hitting over 100 degrees.

[Mr Bill]

Originally posted by kenthagler

Today, I measured 104 outside temp, 115 static pressure,

What?

[amickracing]

Originally posted by mrbillpro

Originally posted by kenthagler

Today, I measured 104 outside temp, 115 static pressure,

What?

My stab in the dark would be the discharge air of the A/C unit.

[skpkey9]

your low on refrigerant. refrigerant static pressure means nothing, a couple of ounces can give you that reading.

[smokin68]

Originally posted by skpkey9
your low on refrigerant. refrigerant static pressure means nothing, a couple of ounces can give you that reading.


And you know this how?
Call a different service company, alot more readings need to be taken before we can tell what's happening.

[kenthagler]

the readings were taken from me connecting my gauges to the unit. what do you mean WHAT? My question is do the pressure readings sound normal or what? What other info do you need?

[k-fridge]

Originally posted by kenthagler
the readings were taken from me connecting my gauges to the unit. what do you mean WHAT? My question is do the pressure readings sound normal or what? What other info do you need?
No, they seem low. But don't go adding refrigerant because there are several things that could cause the low readings. Seriously, you need to get a tech out there so he can find the root problem.

[indian]

Real techs don't look for the answer online...

[servicetech5]

Spend all that money for gauges and don't know what their are tell you. sell them in a yard sale and call a contractor

[AIR PRO]

this one is gonna be good!

grabbing popcorn and beer. :D

[AIR PRO]

"What other info do you need?"

ACTUAL psig readings, subcooling ,superheat, compressor current draw, delta t temp, IWB temp, ODB temp, model # of AHU/coil, model # of condensing unit, static (AIR) pressure, return air duct size and blower speed setting. That should get the ball rolling.

[4l530]

Originally posted by kenthagler
Today, I measured 104 outside temp, 67 low side and 158 high side pressures.
This head pressure can't be right.
If you meant '258' that would be more in line. But there are all kinds of info needed (what Hawk mentions) to even take a stab at it, which will still only be an educated guess via the internet.
What you really need is a service call.

[gbfromsd]

Yep, your systems all outta whack. Buddy of mine did an install in Dallas - bills in the low 200's now were once like yours at 450 a month.

dont call a good tech and pay the electric company or get a good tech and save yerself some money every month thereafter.

[smngmu]

The carrier went out so you replaced it with a payne,just the compressor(?)Do you mean the CONDENSING UNIT? How long ago? Your pressures are definitely way off but will need alot more info to even come close to guessing.That's about all you can get from here is a guess.You need to call a tech out and have the whole system evaluated.Someone right there with it can give you a better diagnosis than any internet connection ever will.

[reverunbilly]

check your airflow-filters,dirty condensor,dirty evap.etc.

[kenthagler]

Originally posted by servicetech5
Spend all that money for gauges and don't know what their are tell you. sell them in a yard sale and call a contractor

They were purchased for my vehicles, I'd like you to ask some questions about your car so I could make you look like a jerk.

[Edited by kenthagler on 08-27-2006 at 01:53 PM]

[kenthagler]

Originally posted by smngmu
The carrier went out so you replaced it with a payne,just the compressor(?)Do you mean the CONDENSING UNIT? How long ago? Your pressures are definitely way off but will need alot more info to even come close to guessing.That's about all you can get from here is a guess.You need to call a tech out and have the whole system evaluated.Someone right there with it can give you a better diagnosis than any internet connection ever will.

They replaced the whole condensing unit around 2 years ago now.

[jrbenny]

Regardless of expertise this is NOT a DIY site.

DIY threads, questions and answers have a life of their own. What happens, if we post repair instructions that injures the person whom we thought was qualified?

We have Forum Rules (http://hvac-talk.com/vbb/showthread.php?threadid=1241) not to anger you, but because they are well thought tried and true.

We all want to help, but we just can't due to the difficulties of working on the other end of the computer and safety. If we tell you, we tell everyone once it’s posted. It’s here for all to read and try.

Thanks for looking at it from our point of view.

Forum Rules (http://hvac-talk.com/vbb/showthread.php?threadid=1241)

[jrbenny]

Thread closed.