I have a problem with my A/C efficiency. I have a 3 story house 2 floors plus a finished basement (really it's 5 different levels since it is a split level design). Unfortunately it is a single zone for heating / cooling. In the summer, all of the cool air from the AC sinks down to the basement and makes it very cold, whereas the bedrooms on the top level are still uncomfortably hot for sleeping. I have all of the basement vents closed (but they still leak a little) and most of the 2nd level vents closed. There are returns on all levels, but most of the intake seems to come from the second level vents that are closest to the furnace.
Any ideas on what I can do? I would really like to knock the house down and build a green one from scratch, but that isn't very practical or economical. Will blocking the returns on the 2nd and 3rd levels in the summer help or will that make the blower work harder and burn out? I tried a window A/C unit in the bedroom, but it is too noisy to sleep when it is on. The AC is on a programmable thermostat that lets the upstairs temperature get up to 83 during the day before turning on but it then has to run all evening just to get the temperature down to 78 and has to stay on most of the time to keep it there once it hits that. Meanwhile, the first floor is a relatively icy 70. Would it be more efficient to not let the house get as hot during the day?
Thanks!
Any ideas on what I can do? I would really like to knock the house down and build a green one from scratch, but that isn't very practical or economical. Will blocking the returns on the 2nd and 3rd levels in the summer help or will that make the blower work harder and burn out? I tried a window A/C unit in the bedroom, but it is too noisy to sleep when it is on. The AC is on a programmable thermostat that lets the upstairs temperature get up to 83 during the day before turning on but it then has to run all evening just to get the temperature down to 78 and has to stay on most of the time to keep it there once it hits that. Meanwhile, the first floor is a relatively icy 70. Would it be more efficient to not let the house get as hot during the day?
Thanks!
The attic floor is fairly well insulated, except for the attic stairs. Most of the ductwork is in the walls or floors and doesn't run into the attic. I did some experiments yesterday with covering various returns and nothing worked- the temperature actually climbed while the A/C was running. Using a fan to blow air up the stairs seemed to work. We can get decent breezes through the house, but even they can't make it tolerable when the humidity is 80% plus. This may not be worth worrying about as my summer electric bill is only about $30 more than typical. Based on what I hear from others in my area, this already sounds pretty efficient.
