Air conditioner runs constantly
In April I purchased a new Lennox air conditioner. It's supposed to be 15 seer but the outside unit says 14 seer. When I questioned this I was told that the Elite attic unit functions as a 15 seer unit when combined with the outside unit. My house is 1452 square feet. I live in Texas and the temperature is between 95 and 105. After the repair man reset the unit so it would no longer shut off in the hottest part of the day (the first problem was thought to be condensation and water), the unit now runs constantly from about 11:00 in the morning to about 10:00 at night and will not go below 77 or 78 degrees. It runs constantly and it runs from three to five degrees higher than the set temperature throughout the day. I have had the HVAC people out 5 times since purchase of the unit, but they still have not fixed the problem. My question is should a brand new supposedly energy efficient unit run constantly for a11 or 12 hours and be unable to below 77 or 78 degrees until the late evening? My windows are closed, my shades are down, and the darn thing is brand new. What could the problem be and shouldn't they be able to fix it?