I just got 2 new HVAC systems installed (upstairs and downstairs), and
I noticed during the day, the downstairs unit doesn't want to hold the
temperature. The other day, I had it set for 78, and it crept up to
82 (starting around 3PM), and didn't get back below 80 until 10PM.
Now it's hot here in Atlanta for the past few days, but these are new
units (2.0 ton downstairs and 2.5 upstairs). The upstairs unit seems
to maintain the temperature without a problem.
Today I set both units at 75 (cooler than usual - just a test to see
if they hold). The upstairs is still 75, the downstairs is 78.
Also, in the evenings (with the downstairs unit constantly running) I
sometimes feel a little warm (not terrible) sitting in the den, but
then feel a burst of cool air (like the unit just clicked on).
Any ideas what could be going on? Could the weather (97 outside right
now) be the culprit? (Though my upstairs maintains without a problem)
Or the thermostat? Or bad unit?
The installer says he is going to try some "expansion valve" at the
coils - does this make sense to anyone?
This is a reasoned guess, ha.
The downstairs unit id not working properly, which could be for many
If he is installing TXV metering devices on the E-Coils, that's what
they should have to begin with.
Do a little reading & thinking, also take some temps indoors & outdoors
at the condenser.
Also, get a percent humidity gauge.
Here are two of the page links:
First the Ductwork Design & functioning -
After the ductwork & airflow is correct -
WISDOM PRINCIPLE DIRECTED EMPOWERMENT COMMUNICATIONS -
THE REAL POLITICAL ISSUES and WISDOM BASED PEOPLE EMPOWERMENT
If I were you:
1. Get another HVAC company out and have them look over both systems.
2. Have them also provide you a heat load for downstairs system to see if
the first HVAC company put in the right size system.
So have the installing company diagnose and correct the issue.
I have lots of ideas, however, the exact problem can't be located right now.
Ya see, I sent my crystal ball in for calibration last week. So you might
check back in a week or so.
Don't know, what design temperatures are listed in your manual J calcs?
Or an installation issue
Or a refrigeration issue
Or a ducting issue
How many guesses would you like?
It makes sense that they don't know what the actual problem is... as if they
knew, they wouldn't be *trying* anything. They would be correcting the real
issue and know what that real issue was by doing a proper diagnosis.
Any chance you went with the lowest bidder?
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