[daisyque]

Is it much more cost effective to use 220v on a portable air conditioner for a small room vs using 110v:confused:

[tkrussell]

Assuming the same BTU rating between a 240 volt and a 120 volt AC unit, there will be no or negligible difference in energy costs.

Using 240 volts over 120 volts, for any device that draws the same power, does not help save power.

I believe you need to refer to the Energy Star SEER rating to find the lowest rating to compare units for energy costs.

I will copy this over at HVAC forum, to see if any of the HVAC experts can help with choosing a unit.

[hkstroud]

No, there is no inherent difference in the cost effectiveness of a 240V verses 120V appliance.

[KISS]

I'm going to add a comment here. A 120 V appliance vs a 240 V appliance needs heavier copper wire for motors etc. thus a 120 V appliance CAN be more expensive.

Wiring in the home for 240 V appliances is a little lighter and thus easier to manage and less expensive.

On the downside, you need 2 spaces in the panel and a double breaker.

With AC units, you almost always need a separate circuit and thus, it really doesn't matter. It would be adviseable to upgrade the wire size to 12 AWG even if calculations say otherwise, so you could convert it to a 20 A/120 V outlet in the future.

[tkrussell]

To be clear, all of this is correct,

I'm going to add a comment here. A 120 V appliance vs a 240 V appliance needs heavier copper wire for motors etc. thus a 120 V appliance CAN be more expensive.

Wiring in the home for 240 V appliances is a little lighter and thus easier to manage and less expensive.

On the downside, you need 2 spaces in the panel and a double breaker.

With AC units, you almost always need a separate circuit and thus, it really doesn't matter. It would be adviseable to upgrade the wire size to 12 AWG even if calculations say otherwise, so you could convert it to a 20 A/120 V outlet in the future.

But in regards to labor and material costs, not energy costs, which I believe was the origianl intent of the question.

If not, then I will sit in the corner and shut up.