We’ve all been there before. Lying in bed, having issues falling asleep because of the heat of a hot summer’s night. If you’re fortunate enough to have a home with central air conditioning, then you’d know how handy it can be to own one when it’s particularly warm out. However many older homes may not have a central air conditioning. Air conditioning models for windows offer an effective solution for cooling a room at low cost.
But before shopping for an air conditioner, it is important to do a few checks. Find the best place to install it, select a compatible type of air conditioner, verify the amount of British Thermal Unit (BTUs) needed, etc. and since air conditioning units can be energy-intensive devices, there are a few tricks to avoid a less than satisfying electricity bill.
Types of air conditioners
Air conditioning units are divided into 4 categories: window, wall, central air, and portable units. Each one has its advantages and disadvantages. Window and portable products are more affordable, easier to install, and can be recovered if you move. However, they are noisier, block the window where they are installed and are designed to cool one room at a time.
Unlike the window unit, the wall and central air conditioning systems are made up of several modules. They are powerful, can cool an entire house or apartment and provide great comfort. However, they are expensive, require regular maintenance and require larger installation work.
Although window units are more accessible, they require professional installation. If you are not a homeowner, you should check with the property owner to see if that installation is allowed in your home; and if you live in a condominium, ask the landlord if there are any rules regarding the installation of an air conditioner, and if that is something the building’s superintendent can install.
BTU vs room size
BTU stands for “British Thermal Unit”. This measurement gives the amount of heat that the air conditioning can transfer in one hour.
The power of window air conditioners ranges from 6,000 to 28,000 BTUs.
Note that if you choose an air conditioning model larger than 18,000 BTUs, you will likely need to operate it using a 220-240 volt power supply.
So, how many BTUs do you need? Energy Star created the following chart:
Area To Be Cooled (square feet) | Capacity Needed (BTUs per hour) |
100 up to 150 | 5,000 |
150 up to 250 | 6,000 |
250 up to 300 | 7,000 |
300 up to 350 | 8,000 |
350 up to 400 | 9,000 |
400 up to 450 | 10,000 |
450 up to 550 | 12,000 |
550 up to 700 | 14,000 |
700 up to 1,000 | 18,000 |
1,000 up to 1,200 | 21,000 |
1,200 up to 1,400 | 23,000 |
1,400 up to 1,500 | 24,000 |
1,500 up to 2,000 | 30,000 |
2,000 up to 2,500 | 34,000 |
Other variables in the equation:
- Add 600 BTU per person generally occupying the room;
- Add 10% if the room is very sunny
- Remove 10% if the room is in the shade;
- Add 4,000 BTUs if the air conditioning is in the kitchen.
Increase the energy efficiency of the air conditioner
An air conditioning solution consumes a lot of energy. In fact, anywhere from 5% to 10% of the world’s electricity consumption comes from air conditioners. Fortunately, there are many ways to reduce the energy footprint of your air conditioning.
Use the timer. Most models offer this option. You can then program the air conditioner to turn off and turn on according to your usual schedule.
Choose the right model. An air conditioner that is too powerful for the room will spend its time turning on and then off. An air conditioner that is not powerful enough will run non-stop and could wear out faster.
Fan. Circulate air and cool more easily with a ceiling or portable fan.
Seal. Make sure the installation of your air conditioning is airtight. Make sure there is no leakage around your air conditioning unit.
The hood and the bathroom to the rescue. Small tip: operate the hood and the bathroom fan in concert with your air conditioner. This will help lower the humidity and circulate warm air outside your home.
Keeping your property at the right temperature is not just a matter of comfort. Adequate temperature and humidity level at all times can help prevent mold and weather damage. Take a look at your home insurance policy. Check if your coverage includes damage related to an air conditioning unit.