Window unit vs. Central air

harryvetchJuly 25, 2007

I'm sure this has been covered, and I apologize to re-hash this.....But

My question is....what is the comparison in electrical use between a window unit (let's say 6000BTU) vs. that of a central unit (no idea of BTUs)?

If you want only to cool a bedroom overnight, is it better to run the 6000BTU unit or central air?

Thanks,

Harry V

Thank you for reporting this comment. Undo
mr_havac

6000BTU

    Bookmark   July 25, 2007 at 6:20PM
Thank you for reporting this comment. Undo
garyg

Harry:

The smallest central air unit is 1.5 tons (18,000 btu/hr). The 6000 btu unit would be much cheaper to run to cool a bedroom only. If you run a central air unit, you are cooling every room that has a supply vent. The newer window units are very energy efficient compared to ones from a few years ago.

    Bookmark   July 25, 2007 at 8:25PM
Thank you for reporting this comment. Undo
jdb52

We do this every night in the bedroom with a 6000 BTU GE unit. It uses about 3.5 kilowatts per night (11 hours run). And this is at a temperature of 71. The central unit would be far more expensive. That's why we do this.

    Bookmark   July 25, 2007 at 9:05PM
Thank you for reporting this comment. Undo
mike_a31_yahoo_com

I installed central AC 2 years back and started to ask the same question after a few $150 July electric bills. I found a really cool cost and usage calculator at www.energystar.gov. Apparently, A 7000 BTU room AC in a 400 pk hr zone (SE Michigan) costs $668/yr to run at $.1644/kWh. A 1.5 ton cental AC unit (bigenough for a 1500 sq ft, 1.5 story home)costs $243/yr. This didn't make sense to me. Afterall, I never had $150 bills when I used the window unit. Then I remembered 2 really important facts. One, I rarely used the window unit because I preferred to keep the window available for outdoor air and because to room unit was so noisy. Second, electricity prices have jumped a lot in the recent past and are probably a lot higher than when I used the window unit.

Here is a link that might be useful: Savings Calculator

    Bookmark   August 2, 2007 at 5:55PM
Thank you for reporting this comment. Undo
mike_a31_yahoo_com

WHOOPS! Caught a serious error! I was reading the lifetime cost for the window unit, not the annual cost. The corrected stmt would be. A 8000 BTU room AC in a 400 pk hr zone (SE Michigan) costs $37/yr to run at $.1644/kWh. A 1.5 ton cental AC unit (bigenough for a 1500 sq ft, 1.5 story home)costs $243/yr. We had a few hot streaks this summer, so I will probably spend about $300 on summer electricity. I only put the central AC on for a hot streak. Otherwise, I leave it off. I suppose that's the convenience cooling only 1 room; it's not a huge money proposition to use the AC.

Here is a link that might be useful: Savings Calculator

    Bookmark   August 2, 2007 at 6:14PM
Sign Up to comment
More Discussions
Nozzle size for Oil Burner ??
I have a Slant fin oil furnace that heats my water...
big_al_41
Is 16 SEER Lennox A/C 5X better than 18 SEER Goodman?
I bought a bank repo home 2 years ago in San Diego....
davidahn
ERV Systems
Hello: Is it really safe to forego bathroom exhaust...
Dona Dinkler
2 Stage vs 1 Stage
I am trying to decide what HVAC replacement system...
cms9323
Heat pump choices for first timer. Advice??
Hello, First post, great place you all have here. We...
adayrider
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™