Is this acceptable HVAC performance?

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I just had a new HVAC system installed in a new house and have not paid for it yet. Today the temperature is 100 outside. I have my thermostat set to 77 and the actual temperature is 81. (This is upstairs, downstairs a separate system is maintaining the selected temperature.)
I am getting about a 20 degree drop. Is that acceptable or should the system be doing better?
Thanks for any help!
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On 8 Aug, 16:45, snipped-for-privacy@aol.com wrote:

How long has it been running? What was the temp when you begin to cool it down?
It could take many, many, many hours to drop a 100 degree space, with all it's 100 degree furnishings, the full 23 degrees.
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DerbyDad03 wrote:

In addition, if everything in the home is loaded with the latent heat of humidity it will take many times longer to pull the sensible temp reading down. Also, the upstairs area usually has a greater heat-gain than the lower floor area.
http://www.udarrell.com/latent_heat_condensation.html
What SEER Rating at 82-F ambient is the new unit?
Higher ambient (outdoor Temps) can considerably lower the capacity of an 82-F outdoor temp Rated Ultra High SEER Rated unit. In very hot & especially humid climate zones, I would go primarily by the higher outdoor 95-F "EER Ratings & BTUH performance at those very high application load conditions." I also hope your new unit has a Scroll compressor & a TXV metering device ahead of the E-Coil. - udarrell
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snipped-for-privacy@aol.com wrote:

If you realy have the question if the upstairs unit has been properly charge is have a heat load done to your home.
Also have your system checked to make sure ther is no problems.
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Its set to 77 and its 81 , maybe the thermostat is not calibrated if its cycling, turn it to 70, how hot was everything when you started it, wait a few days and let it run continously, keep the thermostat temp set low so it runs. My installer gave a guarnteed temp drop in writing.
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wrote Re Re: Is this acceptable HVAC performance?:

Here's a way to measure performance:
1) With the house warm, turn the thermostat down so the a/c will turn on and run for at least 10 minutes.
2) After running for ten minutes, and while still running, measure the temp of warm air going into the a/c unit as close as you can get to it. At the same time, measure the cool air coming out of the vent nearest to the a/c unit.
3) A 20 - 25F temp drop is very good. More than 30F and you may have an over sized unit.
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Bullshit, without all the required data, everything is a WAG (wild ass guess).
Now, if you want to talk about:
TESP, CFM SP, ST, SH LP, LT, SC DB, WB AT, CT, CDT ST, RT, EDT CA, CRLA FA, FRLA Etc.. we can get somewhere.
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Oh bullshit. What's the superheat?
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snipped-for-privacy@aol.com wrote:

Stick a thermometer in the vent. The A/C should be putting out air about 20 degrees cooler than the air that goes into the system (ambient). If you're getting a 20-degree drop, it's as good as it gets.
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wrote:

20
You're assuming that a lot of things are correct.
20-degree drop doesn't mean jack shit.
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kjpro @ usenet.com wrote:

It's not as bad as all that. It's not a definitive indicator of system health, but it is in line with typical performance of typical healthy systems.
In other words, you wouldn't expect to see a 5 degree difference or a 50 degree difference -- those would likely be an indication of something not quite right, or some exceptional circumstance.
All rules of thumb are imperfect.
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kjpro @ usenet.com wrote:

Pssst! This is "alt.home.repair" not "alt.hvac" - you're in the wrong group.
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group.
Pssst! I know "HVAC" and "you don't" - so, quit handing out inaccurate information.
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Wrong :-)
Nick
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LOL
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On Wed, 08 Aug 2007 16:45:45 -0400, snipped-for-privacy@aol.com wrote:

If you have not paid, you must return your 81 degree air and get hotter air in return. I'm sure they have an air exchange place nearby.
Your cool air will be sold to defray your debt.

20 degrees is about as good as you'll get.

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mm wrote:

20+/- degrees from the inlet to the outlet is typical. That says nothing about the difference between the indoor and outdoor temperatures. Clearly you can condition down to 65 degrees indoors even if it's 110 outside (but it will cost you $$) with a big enough system. Just go to any shopping mall for a demonstration.
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Thanks for all of the replies. In answer to some of the questions: The system has been on for a couple of months. The system consists of 3 units (one downstairs and 2 up). The upstairs is the problem. The home is well insulated. I have actually paid 60% of the contract cost. The contractor has a little more work to do (load balance and a couple of other minor cosmetic things and agrees no additional payment is due until all of the work has been completed. He has been very slow completing the final items.)
The exterior temp I gave and the interior temp indicated by the thermostat are correct.
To me as home owner, I don't care about all the technical aspects. My question is simply: "I hired a company to design and install a system. They did. Is it normally considered acceptable for the interior temp to to be 81 when the exterior temp is 100 on a very sunny day."
If the answer is "Yes, any lower and your system would be oversized" then fine. If the answer is "No" then the contractor should correct the situation be it the freon charge level, unit size, duct design, airflow rate, j page calculations, or whatever.

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It should be doing better. We had the same problem for years with our unit and could never get below 80 if it was 100+ outside. Other houses in the area could reach 70 if they wanted. We eventually sold the house and the new owner's inspection showed up that the unit was not big enough for the house. We put some money in escrow for them so the whole thing would just go away.
BTW, we had for years been trying to get A/C people to find out what was wrong but we would have been better employing retarded chimps. ALL of them were useless cretins. Not one of them (7 or 8 different people) said the unit was too small and it was just fine - but it wasn't.
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for

to
What temperature is in the manual J calculations?
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