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By: Holger Czukay on Thu May 29, 2008

As usual, this summer will be hot, hot, hot, and turning to central air conditioning or window air conditioning to stay cool can test your temper by raising your electrical bills. There are still ways to beat the heat and save money on energy bills, though, and I’ll cover them in this, as well as drop some basic science so we can stay cool in the pool!

Window Air Conditioning Units
When you go out to buy a window air conditioning unit, you should know that larger isn’t always better. When determining what size of air conditioning unit to get, think about the size of the room it will be in, what directions the windows face, and whether it will be in direct sunlight. A window air conditioning unit that’s too large for whatever room it’s placed in will use more energy and end up costing you more.

The SEER Number
The efficiency of Central Air Conditioning systems are rated according to a SEER number. SEER stands for Seasonal Energy Efficiency Ratio, and the higher the SEER number, the more efficient the air conditioning unit is. 13 is the lowest SEER number one should have on a Central Air Conditioning Unit, and if you’re in a warmer climate, you should start at 14.

The EER Number
The Energy Efficiency Ratio (EER) is a measure of how efficiently an air conditioning unit will operate when the external temperature is at a specific level (95 degrees F). A less efficient system costs more money, and wastes more energy. Your EER number should be 11 or higher on your room air conditioning unit. Many of the more efficient units cost more, but if you live in a warm area, or an area subject to higher summer heat (such as certain areas in the east coast of the United States and Canada), the money you save on electricity bills will eventually cover the cost of the air conditioning unit.

Maintain Your Air Condition Unit
To extend the life of your air conditioning unit, and to ensure its efficient and not wasting power, you should always perform regular maintenance. Maintenance can consist of replacing your filter monthly, while it’s in use, and before the summer, having a professional service it.

When To Replace Your Air Conditioning Unit
Air conditioning units are, after heating units and systems, the most expensive of all energy using systems in the average North American home. Older air conditioning systems may have lower SEER ratings, and if you happen to have one with a rating of less than 8, you should, if possibly, immediately replace it with a more energy efficient air conditioning system.

Install a Thermostat
Install a programmable, digital thermostat that allows you to vary your home temperature depending on when you’re home. 78 degrees is an acceptable temperature when you’re at home, and if you’re going to be out of the house, you should let the heat rise to 86 degrees.

The Future’s So Bright, I Gotta Wear Shades
The air conditioning condenser (that is, the vent that allows the heat to escape) should be located in an area in your house in the shade, away from furniture and plants.

By planting trees and shrubbery around your home, you can create shade and help reduce the heat of the sun. Plant them primarily on the west and south sides, and you can reduce your cooling costs on your energy bill by 30%.

Closing drapes on the sunny side of your house will stop sun from entering your home and providing unwanted heat, and I often recommend that people install window awnings on the side of their house that receives the most sunlight.

Seal up air leaks in your windows and doors. This will reduce both air conditioning costs and heating costs. Wherever utilities come into your home, such as in the case of plumbing, electricity lines, and dryer vents, you should caulk and seal. Chimneys are especially prone to air leakage, and you should make sure your windows and doors are weatherstripped.

Using ceiling fans that are energy efficient can bring the temperature down when the temperature rises to an above comfortable level. Using ceiling fans in conjunction with your air conditioning unit will reduce the average feel of the temperature inside by 5 degrees (there’s a complicated formula involving the barrier between your skin and the outside world that explains this, and I won’t go into here), so adjust your thermostat accordingly, and remember to only use the ceiling fan when you’re in that room.

If your house is painted a darker color, it will absorb more heat from the sun. If you’re repainting, consider painting the exterior of your house a lighter color.

It’s estimated that 30% of the heat in the average North American house comes in through the roof, so you should ensure your attic is ventilated well with cooling vents in the eaves, and ridge vents and attic fans, which will reduce your electricity bills.

You can put what’s called a reflective window tint on the glass (sometimes called a canaxis) on your windows which will reflect some of the light that comes in, and thus keep some heat from entering.

And a couple of quick final tips on how to reduce the amount of money you spend on air conditioning: if you’re not using a room, shut the door; make sure your air conditioning vents are unobstructed; turn off lights when you’re not using them; and turn off computers, televisions, and other electronics and appliances when they’re not in use.

Well, we've come circle, and all in all, if Rome remains Rome it's going to be hot this summer, and air conditioning's going to cost you a pretty penny. I hope some of these tips help you out!