Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

My hunch is that most ac units aren't that sophisticated, and they just pump air that is "cold enough" or "hot enough" and pump it until temperature rises to the specified value. Is that right?

share|improve this question
up vote 3 down vote accepted

The Thermostat temperature is of the room, at the thermostat. The thermostat has a differential of about 1 or so degrees. Meaning if it is set for 70 deg, it will kick on @ 69 degs., then off @ 70 deg. The actual temperature of the ducts will be something different.

EDIT: The question is about AC so it is ductwork. Each register is likely to be at a somewhat different temperature & CFM due to duct length, size, how many turns, etc. This is often measured with an anemometer.

share|improve this answer
There's a double negative here. The question title asks if the temp pushed out is a specific temp, but the question assumes otherwise and asks if this is incorrect... Your answer is right but when I first read it I was confused.. – Steven Mar 21 '12 at 16:48
Also, this only really holds true for forced air systems. Electric heaters are one type of heating can vary the temperature – Steven Mar 21 '12 at 16:49
It is also worth noting that you can have varied fan speed. Not exactly what he is asking about, but worth knowing about. – Kellenjb Mar 21 '12 at 17:13
Air temp & CFM will vary from each register (see my edit). – SteveR Mar 21 '12 at 18:24

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.