Why does it take so much longer for my AC to work?

[Writer]

My furnace heats my house within minutes. My AC, on the other hand, seems to take quite a bit longer to make a few degrees of difference. We installed our central AC with condenser less that 2 years ago. What physics principle am I missing here - or is my AC not tuned well?

[Shoeempress]

1. Heat adds energy, ac removes it.

[billyskank]

2. Well your AC has a much harder job than your heater

It's all to do with entropy, and the second law of thermodynamics. Entropy is a measure of disorder; the chemical energy in your fuel is relatively ordered (because it's all in one place, ready for use) and so has low entropy, whilst the same energy transformed into heat and diffused through your house is relatively disorded and has higher entropy.

The second law of thermodynamics states that entropy always increases; that is, a system always goes from an ordered state to a disorded state, never backwards. For example, it is impossible to drop a broken plate onto the floor and have it reassemble into a whole plate.

So your furnace works in the direction entropy wants to go: the ordered chemical energy in the fuel becomes disordered heat energy in your house. The AC on the other hand has to work in the opposite direction: its job is to take a disordered state (temperature inside the house and outside is equal) and make it more ordered (temperature lower inside the house than outside). In order to achieve this, it has to do a much greater amount of work to drop the temperature by one degree than your furnace would to raise the temperature one degree.

[Writer]

3. I feel so edumacated.

Thanks for the physics lessons! :)

[billyskank]

4. You're welcome

:)

[OffWithTheirHeads]

5. check the temp of the air going in

your return air register and the temp of the air comming out your supply registers. The difference should be 20 degrees. if it is not within about 1 degree +- your air conditioner is not operating properly. This could be for a number of reasons but After 30+ years in the industry, I can't tell you how many people I've met that are in the buisness and have no idea how to properly charge a system.

Suffice it to say that a good tech is the exception, not the rule.

Also, If you know it's gonna be a hot day, set the A/C so it keeps the house cooler, earlier. It is a lot easier to get the temp to come down from 80 to 70 than from 95 to 70.

Bud

[Lannes]

6. Check your compressor

To see if its clogged up with dirt and your vents as well.Dirt really f'ed up my A/C.