Air Conditioning - Question on pressure (Superheat)
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pityocamptes
08-06-05, 06:19 PM
Do these psi readings sound normal to anyone (need some help):
Outside temperature: 97-100 degrees
Suction line psi: 84
Liquid line psi: 265
Inside register coil: 56 degrees
Suction line temp at condensor: 58 degrees
It is from a goodman 2.5 ton unit and fixed orifice evap coil. I just had the system installed and the unit originally came with 90 psi over 250-260 psi. The tech said this was way to high and went with a basic outside temperature vs head pressure. However, I told him that that didn't seem right since the Goodman spec sheet I was reading said nothing of headpressure but only of Superheat. He initially set it at around 65 psi (suction line) and I had to call him back because it would not drop below 78 degrees inside. I basically read over the spec sheet and told him what I had read (hate to say it but he was not a very bright bukb :wall: ) So he adjusted the freon to the pressures above and said that it fell within the 8-10 degree superheat spec (this after calling the shop). I was looking on the internet and most sites say anything over 80 psi for a suction line is too high as well as anything over 225 for the liquid line. I kept writing down his pressures vs temp and I know that when he was at 80 psi on the suction line that the line temp was around 62-64 degrees. He basically said that the pressures/temp he got to was the best he could do. I contacted Goodman to see what they had to say, waiting for response. Call me paranoid, but I really don't want to blow a brand new system and if I can get some feedback here I can inform him that he may need to make some changes. Can't afford to call a whole new contractor. Any help appreciated!!! Thanks.!
Outside temperature: 97-100 degrees
Suction line psi: 84
Liquid line psi: 265
Inside register coil: 56 degrees
Suction line temp at condensor: 58 degrees
It is from a goodman 2.5 ton unit and fixed orifice evap coil. I just had the system installed and the unit originally came with 90 psi over 250-260 psi. The tech said this was way to high and went with a basic outside temperature vs head pressure. However, I told him that that didn't seem right since the Goodman spec sheet I was reading said nothing of headpressure but only of Superheat. He initially set it at around 65 psi (suction line) and I had to call him back because it would not drop below 78 degrees inside. I basically read over the spec sheet and told him what I had read (hate to say it but he was not a very bright bukb :wall: ) So he adjusted the freon to the pressures above and said that it fell within the 8-10 degree superheat spec (this after calling the shop). I was looking on the internet and most sites say anything over 80 psi for a suction line is too high as well as anything over 225 for the liquid line. I kept writing down his pressures vs temp and I know that when he was at 80 psi on the suction line that the line temp was around 62-64 degrees. He basically said that the pressures/temp he got to was the best he could do. I contacted Goodman to see what they had to say, waiting for response. Call me paranoid, but I really don't want to blow a brand new system and if I can get some feedback here I can inform him that he may need to make some changes. Can't afford to call a whole new contractor. Any help appreciated!!! Thanks.!
DNT1
08-06-05, 07:54 PM
Look I do not have a chart in front of me but if this guy did not take the return air wet bulb temp and dry buld outside temp and use a chart to determine the correct amount of required superheat your charge level could be and probably is off by a bunch. Besides that if he is using cheapo temp probes and gauges his readings could be way off base. The correct procedure must be used or you might as well just write some figures on a dart board and sail a dart at it LOL. Call around and find a tech that knows what is going on and pay him appropriatley for his services. Pressure actually mean very little as they could be extremely high on both sides during initial cooldown of a hot interior or very low on low ambient low interior temp days.
mattison
08-07-05, 07:30 AM
DNT is correct. You may want to call your installing contractor and speak to the owner/manager and explain your concerns and request that a tech that actually knows how to charge a system using superheat/subcooling be sent out to correct your problem.
GregH
08-07-05, 08:25 AM
pityocamptes,
You have been previously warned (http://forum.doityourself.com/showthread.php?t=225860) that we do not provide information for diy a/c installs but continue to come on here on the ruse of a friend of a friend doing the install of the refrigerant.
Thread closed.
You have been previously warned (http://forum.doityourself.com/showthread.php?t=225860) that we do not provide information for diy a/c installs but continue to come on here on the ruse of a friend of a friend doing the install of the refrigerant.
Thread closed.