Results 101 to 150 of 166
Thread: low high-side pressure, help
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08-07-2009, 03:37 AM #101
Re: low high-side pressure, help
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08-07-2009, 03:50 AM #102
Re: low high-side pressure, help
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08-07-2009, 05:00 AM #103
Re: low high-side pressure, help
at this point i have nothin to loose so ill try the .73 again
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08-07-2009, 07:51 PM #104
Re: low high-side pressure, help
hi
ithink there is miss matching btw the comp&air handler unit it appear that u have a large air hanling unit condenser came with this small orifice should b too small to handle the load u can check the comp brand & serial #
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08-07-2009, 09:35 PM #105
Re: low high-side pressure, help
I tend to agree about the mismatch. The evap seems oversized for the compressor, but then this could be simply an orifice mismatch.
More worrisome is that the condenser seems oversized for the compressor.
If the compressor is undersized (under-capacity) for both the evap and the cond, that probably means the compressor is inefficient.
At this point I'm still hoping that the right sized orifice will show a good condenser load, but that may be just wishful thinking.
As mackking says, at this point there is nothing to lose by trying another orifice.Last edited by Gary; 08-07-2009 at 09:41 PM.
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09-07-2009, 03:46 AM #106
Re: low high-side pressure, help
i put in the .73, set it to 15f superheat but i still have a high pressure on the low side (85psi with a 66f suction line)
the high side psi did rise but only to 225 psi. i couldnt get any more readings because it started pouring on me, but its still not bring the room temp down.
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09-07-2009, 03:52 AM #107
Re: low high-side pressure, help
are u telling me that u think goodman installed the wrong compressor from the factory?
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09-07-2009, 04:07 AM #108
Re: low high-side pressure, help
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09-07-2009, 04:09 AM #109
Re: low high-side pressure, help
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09-07-2009, 04:14 AM #110
Re: low high-side pressure, help
yeah the air in evap was 79 and the air out was 62, i know there is a good difference but it still dont seem cold enough to me.
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09-07-2009, 04:16 AM #111
Re: low high-side pressure, help
how would i confirm an inefficient compressor
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09-07-2009, 04:20 AM #112
Re: low high-side pressure, help
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09-07-2009, 04:27 AM #113
Re: low high-side pressure, help
i couldnt check it at the time because of the rain but i thinkit was around 85
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09-07-2009, 04:32 AM #114
Re: low high-side pressure, help
As the temp in the house comes down the superheat will drop, so you should remove some refrigerant to keep it up around 15F.
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09-07-2009, 04:34 AM #115
Re: low high-side pressure, help
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09-07-2009, 04:40 AM #116
Re: low high-side pressure, help
there may be hope but it hasnt brought it down and shut off yet, do u think this is any indication of how its gonna perform?
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09-07-2009, 04:40 AM #117
Re: low high-side pressure, help
I have to wonder if pix would help. There may be a surprise in store. It has happened with other threads.
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09-07-2009, 04:41 AM #118
Re: low high-side pressure, help
what kind of pics do u want?
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09-07-2009, 04:55 AM #119
Re: low high-side pressure, help
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09-07-2009, 05:00 AM #120
Re: low high-side pressure, help
is the superheat effected by night time or daytime?
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09-07-2009, 05:00 AM #121
Re: low high-side pressure, help
it just shut off!!
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09-07-2009, 05:02 AM #122
Re: low high-side pressure, help
from 830 to 12 to drop it 8f
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09-07-2009, 05:11 AM #123
Re: low high-side pressure, help
When it comes back on would be the best time to adjust the charge.
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09-07-2009, 05:14 AM #124
Re: low high-side pressure, help
will the superheat skyrocket during the heat of the day? or should it stay pretty much the same?
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09-07-2009, 05:20 AM #125
Re: low high-side pressure, help
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09-07-2009, 05:25 AM #126
Re: low high-side pressure, help
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09-07-2009, 05:47 AM #127
Re: low high-side pressure, help
yeah i know
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09-07-2009, 10:46 PM #128
Re: low high-side pressure, help
so far its holding 70f in the room, but it has been overcast and raining today too. so far so good
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09-07-2009, 11:13 PM #129
Re: low high-side pressure, help
Got a full list of temps/pressures?
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09-07-2009, 11:16 PM #130
Re: low high-side pressure, help
nope still rainin, but its running about 35-45 minutes during cycles
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09-07-2009, 11:20 PM #131
Re: low high-side pressure, help
Did you trim the charge to 15F superheat?
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10-07-2009, 03:03 AM #132
Re: low high-side pressure, help
i got in contact with goodman tesh support, they said the system required a .73 orifice(which i installed) and a superheat of 22f because uf the humidity. i did this yesterday and it has worked the best today but like i said it was overcast and raining. anyways here are the reading-
suction temp=62f
liquid line=83f
condensor in=77f
condensor out=88
evap in=66
evap out=53
lowside=72psi
highside=175psi
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10-07-2009, 03:04 AM #133
Re: low high-side pressure, help
this was taken at 10pm and it was wet, 95% relative humidity
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10-07-2009, 06:49 AM #134
Re: low high-side pressure, help
Low delta-T's... high suction... low head... I'm thinking this compressor is inefficient.
The only other possibility would be a leaking reversing valve, but you checked the suction pressure on both sides of the reversing valve and they were identical.
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10-07-2009, 06:54 AM #135
Re: low high-side pressure, help
I found a Goodman service manual:
http://www.hvacpartsshop.com/asc%20series.pdf
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10-07-2009, 08:36 PM #136
Re: low high-side pressure, help
hi
ur air handler is 3.5 tons&condenser is 3 tons there is a miss match
gary tanks for the link&the way u guide him
i think every thing is clear now
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10-07-2009, 09:55 PM #137
Re: low high-side pressure, help
The air handler is rated at 2.5 to 3.5 tons, based on 400CFM per ton. It is currently set on low speed (1000CFM) which should result in a low suction pressure... but the suction pressure is in fact high.
One more thing we can try is to measure the temps of the two cold pipes at the reversing valve. If the valve is leaking across, the temp on the side towards the compressor will be considerably higher.
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11-07-2009, 02:58 AM #138
Re: low high-side pressure, help
would a leaking reversing valve of an inefficient conpressor still pull a vacuum when the suction line is closed?
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11-07-2009, 03:00 AM #139
Re: low high-side pressure, help
you asked if it would pull a vacuum, it did but it didnt do it fast and it wasnt much. ive seen systems with a clogged orifice and they would pull a hard hacuum very quickly.
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11-07-2009, 03:03 AM #140
Re: low high-side pressure, help
also as a bit of info, the tech at goodman said he didnt think the highside pressure was low. but as im learning more of how the system works, it seems it would need a higher pressure to keep the refriderant from boiling in the liquid line, right?
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11-07-2009, 03:15 AM #141
Re: low high-side pressure, help
Where are you measuring the evap air in and air out temps? Best would be at the air handler.
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11-07-2009, 03:35 AM #142
Re: low high-side pressure, help
the return air is right above the air handler about 1ft and the closest out is at a vent 3ft away. its a downdraft.
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11-07-2009, 03:40 AM #143
Re: low high-side pressure, help
i cant measure the out temp right from air handler because it mounts to the floor so i have to use the closest vent
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11-07-2009, 03:55 AM #144
Re: low high-side pressure, help
3 ft away should be accurate.
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11-07-2009, 04:53 AM #145
Re: low high-side pressure, help
Last edited by Gary; 11-07-2009 at 04:59 AM.
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11-07-2009, 05:02 AM #146
Re: low high-side pressure, help
Last edited by Gary; 11-07-2009 at 05:06 AM.
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11-07-2009, 06:08 AM #147
Re: low high-side pressure, help
in reading your post in a/c 101, you explained that the boilding of refrigerant in the evaporator removes the heat from the air(which i understand) but i also understood it to say by raising the pressure in the condensing coil it returned the refrigerant back to a liquid(by increasing pressure and removing the added heat) so i guess my question is, is the system raising the pressure enough to maintain the proper liquid state?
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11-07-2009, 06:16 AM #148
Re: low high-side pressure, help
my next question is, by overcharging and having the wrong orifice, could that have damaged the valves in the compressor?
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11-07-2009, 06:59 AM #149
Re: low high-side pressure, help
R22 at 175psi gives you a saturated condensing temp (SCT) of 93F. In order for the liquid in the liquid line to boil off, its temp would have to be higher than 93F. Its temp is 83F. Not going to happen... and since the two temps go up and down together, it can't happen.
Last edited by Gary; 11-07-2009 at 04:54 PM.
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11-07-2009, 07:03 AM #150
Re: low high-side pressure, help
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