Why Air Conditioning is So Expensive to Run

Do you wonder why air conditioning is so expensive to run?

First of all, let's put things into perspective by taking a look at why your cooling system is eating up all your hard earned dollars just to keep you feeling nice and cool on those really hot days of summer.

Because that's what it's doing right now while you're reading this (if it's the summertime and you're indoors in the cool, that is) if your system is working hard to make you comfortable.

Air conditioners work in a similar way that your domestic fridge keeps its interior cold to stop your food spoiling and keep your drinks cold.

A fridge circulates its internal air through a refrigeration process that uses a compressor to compress a special gas that gets really cold under pressure.

The gas is pumped through a latticework of fine tubes like a mini radiator and the air passes through that latticework to make it cold.

The cold air is then circulated inside the fridge to keep its contents nice and cold.

If you ever pulled your fridge out and looked around the back at the base, you'd see the motor and some of the pipes that are doing the work.

You'd also notice a lot of hot air coming off the motor, which is a normal by-product of the work the compressor does.

Of course that hot air doesn't get let into the interior of the fridge because that would be pretty stupid!

AC Refrigeration Process

An air conditioner does the same thing pretty much, just on a larger scale. Instead of cooling a small, enclosed space like your fridge, it has to cope with the much larger area of the room you're occupying.

Luckily, it is designed for that job and does a pretty good job of it too.

You probably noticed your AC is hooked up to a box on the outside of your home that has a fan in and is busy pumping out a lot of hot air.

That hot air is coming from the compressor in the AC inside, just like the fridge.

That's the whole point of having that machine installed outside: to expel the hot air out of the building.

I'm sure you get it now, that it would be pretty foolish to allow the hot air to circulate around the room being cooled. It sure wouldn't get very cool in there!

Hot Air Nobody Wants

AC needs to vent the hot air to the outside of the house, so the inside of the house can be cooled efficiently. All that work of course uses electricity for each of the components to do their job.

The compressor does most of the work and uses most of the electricity. Depending on the size of the space it has to cool and the temperature you set it to cool to via the thermostat (the setting on the remote), a whole house AC system can use several kilowatts of electricity (thousands of watts) per hour.

Even the smaller portable air conditioner units can use two to three kilowatts of electricity per hour.

If you compare that electricity usage to a regular incandescent light bulb that uses 100 watts, I'm sure you get the idea!

How to Save Electricity used by Air Conditioning

It's not all bad news when it comes to the sheer amount of electricity a domestic air conditioning system uses. It is possible to reduce its power consumption by taking some common sense steps and just being mindful of what you could be saving.

The first place to save power and therefore money (your money--that could be spent on something better), is to do something so simple you'll kick yourself if you didn't already think of it.

Turn Down the Thermostat!

A lot of people have a tendency to want their place to feel real cold when it's real hot outside.

So they set their AC to a crazy low temperature, sometimes as low as 50 degrees... and then they wonder why their energy bill is so crazy high!

Think about that.

For an AC to reduce the indoor temperature to 50 degrees, for example, it would have to work very hard indeed to reduce it by so much, especially if the outside temperature is above 90 degrees. That's a 40 degree drop!

The motor in the AC would be working flat out non-stop to get the level down so far and then keep it there. That would force it to use a huge amount of energy, which is what we're trying to save here.

So the obvious thing to do is to be sensible and set the temperature at a comfortable 72-74 degrees, like you would set the heating in winter. That's a really comfortable temperature and it will mean your AC doesn't need to work so hard to achieve it.

Insulate Your Home

Another sensible thing to do is to make sure your home is correctly insulated. That means having the attic fully insulated as well as plugging any leaks in window and door frames to make sure the cold air stays inside and the heat stays outside.

It works both ways, because a well insulated home will also save energy during winter when the heating system is working to keep you warm during cold weather. Most modern (recently built) homes will have good insulation installed already to comply with modern building regulations, but older homes may not have it.

You can easily check your attic to see. And if there is no insulation, you should consider getting it installed by a professional company because it will recoup its costs in short time and save you money in the long run.

Other Ways to Save Energy

There are several other ways to save on energy consumption and costs by taking some common sense steps with your home to reduce the load on the AC system. I put together a separate article on how to stay cool without air conditioning (click that link to read it) that explains some great ways to reduce the indoor temperature without even needing to run an AC.

Those tips and methods to cool a house without AC will also work extremely well at making your home cooler indoors and take a lot of the load off the AC system if you still need to run it during the hottest weather.