Central air conditioning $$$???

[kubmech]

Well I got Sears down to 6800.00 bucks with a 12 seer 2 ton unit and 7 drops. That's the best they good do, while it's much better than 8500 I still think that's too much money. While I was in the process of getting other contractors for more qoutes, I ran into a guy I worked with a long time ago who just so happens to do heating and air conditioning now. We get to talking...trade some back scratchin'...He needs... I need...next thing you know I'm not breaking the bank. Funny how stuff works out. Thanks a bunch for all the help guys....

Kubmech

 

[Kyle_in_Tex]

Theoretically, the advantage of a compressor shutting down for periods is that it's coils cool down to outside temperature for free(no power) while shut down. (Yes, even 100 degrees ambient is cooler than while its running). The trick is adequate insulation to keep inside cool enough for a while. It is good if you can provide shade for the compressor but do not block any airflow.
Alan, I think maybe what your technician meant was that a 20 degree drop across the evaporator coils could be a ballpark number. So if inside air is 75, then the air at the registers should be blowing maybe 55. There are many factors. Tonnage is one of them. Some guys don't like to see that high of a differential temp.
In far west Texas, when the humidity is low (30% or thereabouts), you can get by cheap with a simple watercooler. Actually putting moisture back into dry air can cool quite effectively too....Kyle

 

[Alan L.]

Kyle, the 20-degree differential might be what he meant, although thats not the way I understood it. However, I still don't know how you would ever get it cooled down if it got hot, if the air coming out of the vents was only 20 degrees cooler than the ambient air.

I do know that when its 100 outside and 68 in my "house", my A/C cycles more than I thought.

My space is close to 900 square feet, and we keep it very cool, as low as 60 at night. We are all electric, with hot water heater and septic running on electric, as well as a 220-volt 5 HP submerged well pump, with lots of irrigation going on. The AC unit is only 10 SEER and the highest electric bill we've had in the hottest part of the summer is $225.

 

[Bird]

</font><font color="blue" class="small">( the 20-degree differential might be what he meant )</font>

Yep, Alan, Kyle's right. He's not talking about the ambient outdoor temperature. Another possible way of putting it is a 20 degree differential between the "return" air and the "discharge" air, I guess. My brothers work on RV air-conditioners primarily, but the same principles apply. I helped one of my brothers replace the compressor once on his home air-conditioner and then he and I once replaced everything but the thermostat on the wall in our parents' mobile home.