[justplumducky]

Advantage of 230v wall unit AC vs. 115v same 12K BTU?

I've already taken delivery of a 12K BTU thu-the-wall unit, and running a dedicated circuit for it soon, because I wanted to not add any load to the bedroom circuit (same as living room circuit where AC goes) to which a buyer later might want to add a small wall unit in order to keep the bedroom door closed at night, or even occasionally in daytime.

If the circuit resistance for 230v 12K BTU unit is same as a 115v 12K BTU unit, then the only advantage is lower amp draw (I = E/R)?

 

[Joeywhat]

I've wondered this as well. Comparing similar btu ranges, it seems the 230 volt units use half the amps as their 115 counterparts... So why bother? Is it just convenience for people who already have a 240v outlet where the A/C goes? I'm not seeing any other benefit.

 

[justplumducky]

I've wondered this as well. Comparing similar btu ranges, it seems the 230 volt units use half the amps as their 115 counterparts... So why bother? Is it just convenience for people who already have a 240v outlet where the A/C goes? I'm not seeing any other benefit.

Now that you mention it, I remember that being one of the reasons for 240v, exactly that in other words... for an existing 240v outlet. Curious to see if there's any other reason.

And at the risk of angering our God of HVAC-R, I've posted this in Electrical also. Uh oh, maybe this is Electrical. Oh well, I'll figure it out sooner or later!

 

[Old Thomas]

In a comparison of the same amount of wattage, 240 volt would use smaller wire, being cheaper to install if it is a long run. There is slightly less power lost to resistance in the wire with higher voltage and lower amperage. Some motors start a little easier on 240 volts. Will you notice a difference in performance or your power bill? Probably not.

 

[seharper]

A/C units have gotten more efficient. Time was, an A/C unit in the 12k BTU class would need a 240V outlet because its draw would exceed 1920W.

So your unit gives up the ghost/you see the electric-bill wisdom to modernizing. Yes, the new unit doesn't require 1920W. But it does require a fair bit of power, and sharing a circuit might not work out. There's a 240V outlet already there for it. What else would you do, bring in an electrician to rejumper it for 120V? The path of least resistance is to get the A/C unit in 240V.