Is my new A/C functioning correctly?

I just replaced my old 3 ton 10 seer with a new Trane 3.5 ton 15 seer variable speed air handler. This is a A/C heat pump unit. My electric bill is exactly the same, the cold blasts and then the house is so stagnant that we have to run a fan to move air in the house. They told me that the unit would be so efficient that I could set my thermostat higher but that isn't so. This doesn't seem right?
  4 answers
  • 3po3 3po3 on Aug 26, 2012
    Has the installer been back to see your place and get a feel for your comfort levels?

  • Ellen H Ellen H on Aug 27, 2012
    Get your installer to come back and check it out. My sister and her husband replaced a unit this year; no change in power bill as promised and not happy with cooling so the installer sent someone back out to recheck everything top to bottom. Found a problem with something set by manufacturer, installer contacted manufacturer for how to reset, problem solved.

  • KMS Woodworks KMS Woodworks on Aug 27, 2012
    How about a ceiling fan or two? A number of years ago I got to spend some time at a time share off the coast of Venezuela...needless to say sea level heat and humidity. The unit did not have any AC at all, the simple use of a ceiling fan felt perfectly fine to me. Considering that 90% plus of the 3 rd world does not have central air and they live in hot humid tropical locations a fan is a luxury. Its just a matter of letting your bodies adapt to the local conditions.

  • If you removed the old unit that was smaller then the new one. That is the issue right out of the box. Almost all AC systems are over sized. The older they are the worse they were. As you begin to seal up your home and make it more energy efficient over the years, that makes the requirement for even a smaller unit being required. The issue is that you now have is that the new system is drawing the temp down to fast resulting in the house temp going down, but with no reduction in humidity. The whole idea of the multi speed system and being as close to the correct size that you can get, is so the system runs longer, and the air drys better. Resulting in more comfort for you. With the higher efficiency even with the longer run times, you should see a noticeable difference in your power usage. Ask the installer to provide you with the Manual J load form that they should have used when they picked out the new system for your house. Also ask them for their license number if indeed they have one. In any case a Manual J is a form that calculates the amount of cooling and heating the house requires based on it's size, location and how it is constructed. Although it could be a setting as Ellen stated, I doubt that is the issue here. In all the years I have been involved in this industry I have never installed a larger unit in a home, and almost all of the time installed a smaller sized one.