Actual performance - Goodman GSH14 - http://www.hvacmechanic.com/ Forums
Original message
| dirtyoldm
 |  "Actual performance - Goodman GSH14"
, posted Mon 11 Aug 07:55  
Just installed a Goodman GSH14 2 ton heat pump.
Cooling seems low - from wet bulb temps we calculate about 18,000 BTUH total. Delta T across coil is 13F instead of spec sheet 16F.
And current is way below the spec sheet - it says 11.8 amps, this one draws 7.2 amps.
Pressures and superheat are as specified.
Goodman's tech guy refuses to believe his product has a problem.
So has anyone measured cooling output and current draw on any GSH14 model?
Are they over-rating them these days?
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Replies:
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| dirtyoldm
| "Actual performance - Goodman GSH14" , posted Tue 12 Aug 09:19
Thanks, but...
We were referring to the detailed spec sheet that shows pressures, current, etc for different ambient temps, air flows, etc.
You can see it at
http://www.goodmanmfg.com/Portals/0/pdf/SS-GSH14.pdf
In the 'detailed cooling' section, look around 800 CFM and 85F ambient temp. Current doesn't change much no matter what the conditions are. Note Goodman shows total current including the fan.
The nameplate shows RLA 10.9 amps, fan 1.1 amps.
So the detailed spec sheet is pretty close to the total 12.0 amps on the nameplate.
We just need to know if our unit is typical.
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| Jojo98
| "Re(1):Actual performance - Goodman GSH14" , posted Mon 11 Aug 22:39
Compressor current will usually be below FLA, especially if the conditioned space isn't very hot. Also, if line voltage is higher than nameplate, you'll have less amperage on the load side. If suction temperature is above freezing, and you have sufficient superheat. I would then check the blower, return, and supply duct for correct air speed and volume. Make certain that the ducts are properly sized.
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| | Houston204
| "Re(2):Actual performance - Goodman GSH14" , posted Tue 12 Aug 21:03
13 degree delta tee is terrible.
Did you get the matching fancoil?
Had the system been off very long?
Is this measurement only across the fancoil or did you measure grill to grill?
"Tip of the Day" Remember to remove power first.
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| | dirtyoldm
| "Actual performance - Goodman GSH14" , posted Wed 13 Aug 10:23
It's in an old oil furnace.
We verified 800 CFM by measuring pressure drop across the coil.
We let it run 10 minutes before taking readings.
It seems to take 5 or 6 min to stabilize.
Wet bulb taken at a hole drilled in the return at the unit, and at the nearest grill. Yes, we checked that the grill is the same temp as the plenum just above the A-coil.
We just want to know if this unit is OK.
In this era of Bill Gates marketing ethics, the specs might be... er, less than honest.
Has no one ever measured the output of an air conditioner ??
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| | Freon
| "Re(1):Actual performance - Goodman GSH14" , posted Wed 13 Aug 15:28
Check the head pressure. With a low amp draw I'd expect low high side... the compressor is not doing any work. If the high side is low then why? Correct piston? And was this a new evap coil and condenser? If it's the old(dirty)coil your cfm may be suspect. If the head is low it could be a sick compressor or not enough refrigeraant... subcooling?
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