Is adding a window AC unit cost-effective?

[49erinnc]

Just wondering if I would save money by putting a small (6K-9K BTU around $130) window unit in master bedroom (single story) and killing the central air during sleeping hours? Would the temp in the rest of the house rise to a point over night that cooling it all back down the following day would defeat the point of adding the window unit?

Just looking for simple ways to cut enery costs.

 

[Heisenberg]

How cool outside does it get at night?

 

[49erinnc]

Originally posted by: Heisenberg
How cool outside does it get at night?

In Charlotte NC and right now, it's getting down to around 75-77 over night, with a good bit of humidity. But beyond this really high spike, I'd say it's around 70 most nights, give or take a couple degrees.

 

[Heisenberg]

If it gets that cool, then I doubt the house will warm up that much overnight. You might want to estimate how much you'll save per month and see how long it'll take to offset the cost of the window unit.