Most people wait until a summer heat wave to give any thought to air conditioning. Then they rush out to buy whatever window unit is available for a good price.
It pays to shop smarter and plan ahead, and consider your options over the winter or spring. Here are some things you should know before deciding on an air conditioner.
1. Central Air Conditioning
The best way to cool your home is with central air conditioning. Installing a new system will cost at least several thousand dollars.
A cooling contractor will calculate your home’s “J load” to determine what size cooling unit you need. Efficiency not only saves on electricity costs, it can mean that the air is cooled at a rate that produces a comfortably low humidity level.
Forced-air heating systems can be adapted to send cool air to ducts in your ceilings, quietly and without blocking your windows with noisy air conditioning units. A fan-and-coil cooling unit is attached to the existing forced-air furnace.
If you are in an older home with radiators, air conditioning ducts can be added and a cooling unit installed, but the cost may double.
In either case, the compressor is separate (so the system is called “split”). The compressor sits outside the house. It is big and not exactly beautiful, and it makes some noise and expels warm air, so put some thought into its placement.
To avoid having ductwork, a mini split system may be an option. The compressor is still outside the home, but the cooling units are installed on the ceiling or wall in each room.
Unlike window units, mini splits do not block your view, and there is no need to keep the window sealed shut. Like ducted central air, these systems are expensive and require professional advice to properly size and install the indoor units.
2. Room Air Conditioners
If you don’t own your home or simply aren’t ready to spend thousands of dollars on central air, you will need to go with a room air conditioner.
Since the warm air needs to be expelled outside, the unit will have to be installed in a cut-out in an outer wall (a “through-the-wall” air conditioner) or mounted in a window (a window unit).
You can mount a window unit yourself, but you should secure it with screws. If the air conditioner is not stable, it could fall out of the window and injure someone, or worse; or it could be pushed in by an intruder.
In addition to window and through-the-wall air conditioners, there are portable units on wheels. This type still needs to be vented out a window, or through a cut-out in an outer wall, using a vent tube.
A properly sized air conditioner is most efficient and keeps the humidity low (instead of leaving you with a clammy room). When choosing a unit, figure out how many square feet of living space you will be cooling, and allow 20 BTUs of power per square foot.
A unit with a high energy efficiency ratio (EER) will help you save on electricity costs, and on the label that may be indicated with the Energy Star logo.
3. Keep Energy Use Down
Air conditioners require a lot of electricity and are expensive to run. They emit carbon dioxide into the environment. Don’t cool your rooms any more than you need to in order to feel comfortable, and don’t cool rooms that you are not using.
Instead of leaving air conditioning on all day when you’re out, use a device to have it come on right before you get home from work. There are thermostats and timers that can be set to turn on the air conditioning later or to control it remotely using your smart phone.
To avoid your home overheating, keep the sun out with window shades, curtains, or shutters, and open windows on cool evenings. Fans can keep you comfortable in all but the hottest weather.
A window fan will draw cooler air in from outside and push warmer air out, and a portable fan or ceiling fan cools your skin by moving air around the room.
4. Maintaining Your Air Conditioner
If you maintain your air conditioner’s filter, coils, and fins, it will cool more efficiently, use less energy, and last longer.
All cooling systems have filters, and they are easy to maintain. Dirt in the filter can block airflow and also get into the coils. If the filter is clogged, dust could be blown into the room.
Some filters can be cleaned and reused, and some need to be replaced. In a room air conditioner, the filter is usually behind the grill and easy to remove. Check the filter at least once a summer, and more often if your cooling season is long or your environment is dusty.
Even if you replace your filter, some dirt will get into the coils and keep them from absorbing heat properly and cooling the air.
In a window unit, usually some coils are behind the filter and others may be farther inside. You may have to take the unit out of the window, remove screws, and open up the unit. Wipe the coils clean, preferably applying a coil cleaning liquid.
The cooling fins on your air conditioner can get bent and impede airflow. You can straighten them by using a tool called a fin comb.
5. What You Need To Know
- For room air conditioners, allow 20 BTUs per square foot.
- Look for a high EER or the Energy Star symbol on the label.
- Clean or replace your filter every spring.
- Don’t cool a room more than necessary.
If you have any questions or comments, please write in our comments section. And share this with your friends and family!