Help! - I will start with a little background. I live in a 1400Sq ...

HOMEOWNER CRIES FOR HELP...

posted: September 8th, 2008 - 2:04pm

QUESTION:
I will start with a little background. I live in a 1400Sq Ft house in Savannah Ga with a 3 ton AC unit. The house was built in 2005. (Everything is new). It is a Mitchell built pre-fab home, which is Energy Efficient.
Last August while in the house (with similar outside temps) I kept my thermostat on 68 and the house stayed at a cool 68. The cooling unit was able to shut down throughout the day and night and only ran when it needed to and my power bill was $225. This past March the unit stopped cooling well (staying around 74/75 when set on 72) and we called out a service tech. The service tech stated that the unit was fine and it was just getting hot outside. About a week later the unit stopped running all together and another service call was placed. At this point in time it was determined that a transformer had blown. The transformer was replaced, a fuse was placed in line, and the thermostat was replaced.
A couple of weeks later it still was not cooling as well as it has the previous August and when the tech came out he said it was low on Freon, charged it, and said he would be back the next day to find the leak. The following day he came out, stated that there was not a leak and left. A couple of weeks later, still no change, slowly getting hotter in the house as the summer rages on. Called service back out and was told that it was overcharged. The house continued not to cool for weeks staying in the low 80's during the majority of the day and night. I finally was able to get a real AC man out who checked Freon levels with the super heat/cool? Technique who determined that it was still overcharged but stated didn't seem as if it would be enough to cause the problems that I am having. The coils outside and inside are spotless. The condenser is pulling the correct amount of amps. The duct system was designed poor, but there are no leaks. His recommendations are to increase the intake size (appears small) and add an attic fan. My problems are this. Last year it worked fine in the same temp weather with the same structural design. Other houses with the exact same floor plan and size AC unit are not having any problems. My bill has increased from 225 to 450 because the unit is never able to shut down. My house won't cool lower than 78 from about 11AM-11PM. What am I missing????

ANSWER: I did not see anything about the temperature drop on the unit it should be around 17 degrees my guess is that the heat is on at the same time as the cooling or that hot air is getting into the return.
These are commonly missed issues as the first thing most tech grab are their gauges instead of a thermometer.
I hate that you have had so much trouble and I hate for you to call them back or call someone else but you need to check your return duct to see if any hat air is getting in then check to see if you have some from of heat on the fastest way to find these things out is start taking air temperatures.