Temperature difference

[dan sw fl]

Originally posted by Freezeking2000
A properly sized cooling system will run 100% of the time at design temperature. Has it been hot?

AND maintain the residence at ~20'F less than the Outside Temperature.

(i.e. East Coast, NOT AZ or similar where Delta T >> 30'F)

Thanks, King!

[jtjgvle]

To my knowledge I don't have a variable speed air handler. I have adjusted the thermostat enough so that the AC will at least cycle some (although it doesn't stay off for very long) rather than running constantly (77-78) I'll just have to get used to it I guess. Unfortunately my work building is always about 71 so I get used to it being really cool! I'm going to pursue some more window coverings and see what happens. Thanks to everyone for your continued suggestions.

[Panama]

The temperature drop should be measured just before and just after the evaporator coil. You'd be surprised how much the air can warm up in both the return ducts and the supply ducts. If you have a 15 °F difference between a supply grille and a return grille, you just may have a 17°F or more difference at the coil itself.

The best way to find out where your cool is going is to hire an expert to test for leaks in the house with a blower door and for leaks in the ducts with a Minneapolis Duct Blaster. The right expert can also suggest insulation improvements.

One place to look for an expert is at http://www.energyconservatory.com.

[zzyzzx]

Originally posted by Freezeking2000
A properly sized cooling system will run 100% of the time at design temperature. Has it been hot?

I was going to say this too! I moved into a townhouse about 1.5 years ago after living in basement apartments for more than 10 years. The amount of time I have to keep the A/C on is way more!

[jtjgvle]

ZZYZZX, I guess alot of th eproblem is getting used to a new type of home. This is my 2nd summer in a 4000 sq ft historic home, previously I lived in various small apartments, last summer I used 2 window units to cool the most frequently used rooms in my house and this is my first summer with the new HVAC installed.

[coco]

delta should be 15-20 degrees not 10-15

[bornriding]

With relative humidity between 40 & 60 % - The delta 't' I look for is 20 degrees 'f' between return & supply.
And yes, with a 15 I would be calling the installer

I am in Alabama, so I know what conditions you have in Atlanta. But if you have a hgh eff. system, with a variabl speed blower, you may not get the delta 't'.