The most cost-effective way to use a ductless air conditioner


I’ve heard an *outrageous* amount of contradicting opinions. One says to leave it on all day, another says to turn it off when you’re away from the house, and then another says to adjust the temperature accordingly throughout the whole day. But even within the answers that I have been finding, there is a bunch of terminology that I can’t wrap my head around.

I live in a 2 bedroom apartment with ceiling fans in every room. There is one ductless airconditioner in the living room which is the center of the living space. What’s the most effective way to go about using it?

In: 7

It all comes down to that there’s no such thing as a free lunch. Any time it’s working, it’s taking power to run it.

Whether to run it all day or not is a question of personal comfort. Are you in some hellishly hot and humid place? Then it might make sense to run it constantly, to avoid excess humidity in the house and for the sake of the comfort of any pets and so on. But make no mistake, that’s going to cost you. You’re just deciding it’s worth it.

The less you use it, and the less it has too cool, the cheaper it’ll be. So you’ll save by not telling it to cool as much, by avoiding using it when possible, and by insulating the area (eg, keep the doors closed). Avoid running fans and devices inside if possible, because they make heat that’ll take extra effort to get rid of. If you’re really serious about it, it could make sense to do something like placing your gaming computer in another room and just running wiring to it.

One thing that may make sense is to look at how your power company prices power, and optimizing for that. If power is very cheap at night, you could actually save by making it cool more than you need at night, and letting things warm up in the morning.

Only turn it on when you need it.

Some people think if you let the room get warm, it takes extra energy to cool it back down. This is wrong; keeping the room cool takes much more energy than that. Because if the room is kept cool, more heat seeps into the room throughout the day than if you let it warm up. So there’s more heat for the air conditioner to remove.

The only possible exception is, if you are on a “time of use” electricity plan, it may be better to run the AC all night on cheap electricity and then keep it off during the day.

It really depends on the temperature, the humidity and how well you’re house/ room is insulated.

You mean like a window unit ?

If it’s running it’s using power. Period

So it’s best to run it as little as possible. So if no one is home turn it off. If you are home and don’t mind the heat while you are just lounging around keep it off or low.

If you need to be shaking from cold to sleep full blast it right before bed.

It’s not actually more efficient to leave your house on 70f all day opposed to turning the ac off all day then come home and turn it on

Buuuut there is an exception and that is I’d your electricity cost is based on demand if this is true, everyone comes home from work like you and turns the ac on. If this is the case it might be better to run the ac at different times and harder to keep the cooling effect. This will also depend on insulation for the home.

But let’s say it’s the weekend and night time electricity is half price. It’s probably better to rub the AC to 65f and then set it up to 70f in the morning than it would be to just leave it at 68f. All day and night.

But know this.

Air conditioning is very efficient especially for window units (non portable) so all that matters for you is run time and the cost at the time of your electric bills