How long should it take to cool off a raised ranch house with central air?? This is our first summer in this new home with existing central air, not sure how long it should take or what I should be doing, should I close up some vents?

There are too many variables to predict. These are some things that it depends on:

1. The outside temperature
2. The temperature inside the house when you turn the AC on
3. The insulation of the house
4. The size of the house
5. The capacity of the air conditioning system.

What "vents" were you thinking of closing?

I was thinking of closing off some of the vents in the basement...

1. The outside temperature... around 30 degrees (im in ontario)
2. The temperature inside the house when you turn the AC on.. my husband said around 27 degrees
3. The insulation of the house... needs some work... lol
4. The size of the house... a three bedroom raised ranch with finished basement around 1500 square feet
5. The capacity of the air conditioning system... not sure

Closing off basement vents is a good idea since the cold air isn't needed down there.

I'm going to make a guess that the house should cool off within 2 hours. If it takes much longer, you might have to have the system checked.