New 18 SEER ....same KWH usage?

[tperk100]

3 months ago, we replaced our 20 year old 4 ton, 9 Seer Amana HP with a new Amana 18 Seer model. For the last 2 months our KWH usage has not changed from last year!!!! The technician says all is well.

Interestingly, the Honeywell VisionPro thermostat set point and the room temperature are always the same. On one hand this is real good, but it makes me wonder if the system is turning off and on too often.

When the system was first installed, the air handler was not set up properly, and the compressor would run very frequently for very short periods of time WITHOUT the compressor fan turning. The compressor cabinet would get VERY hot. This was corrected during the first month, and the tech said that this did not hurt the equipment.

Any suggestions will be appreciated.

[HayZee518]

probably not in the original design, but for the condenser fan, I'd install a time delay relay so once the fan turns on it would run for a preset time then shut off. on-off, on-off is not too great for a fan motor. the original part, a sensor turns on the fan motor contactor depending on condenser temperature and/or suction line temperature, or even a suction line pressure switch.

[tperk100]

The condenser fan runs OK now since they corrected their installation error. At this point I am concerned that our electricity consumption does not seem to have changed.

[HayZee518]

then I wouldn't worry about it. if it had changed to a higher value, then I would start looking.

[tperk100]

9 seer to 18 seer, and we have had a mild summer here so far. I should see a substantial decrease in electricity consumption. Why would you think I should not?

[HayZee518]

I would think that usage should drop but maybe because the rating is double what the last unit had the electrical demand is the same considering the run time iw reduced.

[tperk100]

I appreciate your trying to help me but I find that VERY hard to believe.

[HayZee518]

ok, numbers don't lie -so- find a clamp around ammeter and apply it to one major wire on your unit, say a wire that comes off one leg of the breaker that feeds the unit. I'm assuming its 240 volt. take the amp reading and multiply that times the voltage. power measured in watts equals volts times amps. now if you want kwh, multiply that reading by 1000 and then times 60 [min] the draw in thousand watts for one hour.

[HayZee518]

Annual Cooling Bill
6 SEER 10 SEER 11 SEER 12 SEER 14 SEER 18 SEER
$600 $360 $330 $300 $240 $200
$800 $480 $440 $400 $320 $267
$1,000 $600 $550 $500 $400 $333
$1,200 $720 $660 $600 $480 $400
$1,400 $840 $770 $700 $560 $467

[tperk100]

What good will calculating the Wattage do, since I do not know what the old system was drawing to compare it to the new one?