sailor86

My son's bedroom doesn't cool off very efficiently during the heat of summer via the central system. We're planning on getting him a window unit. From what I've heard 220 is more efficient, draws less current, and hence is easier on the electric bill. But his room is only 12' x 11'. Is it worth a 220 unit? Would it be easier to just install a 110? Even so, I'd like to run a dedicated circuit so's the lights don't dim and all that.

kok328

If your willing to pull a new circuit then pull a 220V circuit for the power efficiency.

Keep in mind:
- 110V window shakers are more common that 220V units
- a 220V unit doesn't cool any more than a 110V unit
- might as well pull a neutral with this circuit so that you can later use one leg and the neutral as a 110V circuit

joecaption

It's an old wives tale the 220 cost less to run then 110 volts. It does draw about half as much amperage but uses the same amount of eletricity.
A 220 volt motor also runs cooler and most often last longer.
Have you concidered try to find out why that room is hotter?
Not enough insulation under the floor and in the ceiling, unbalanced HVAC system, old windows, furniture sitting on top of the registers. All simple things to check and cheaper then an A/C and the power to run it.
http://wiki.answers.com/Q/Does_a_220_volt_Air_Conditioner_cost_less_to_opera te_than_a_110_volt_with_the_same_btu's

sailor86

That particular br sits on the east end of the house. The sun beats on it all morning long. I may consider getting the ducts cleaned.

joecaption

Duct cleaning will do nothing to make the ducts put out more cold or hot air.
Planting some shade trees on that end of the house, adding solar film on the windows to help reflect the heat, keeping the curtins closed to slow down cooling loss are cheap things to try.