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Air Conditioners: From Maintenance To Buying New

Heating and Cooling, Interior Published 10/27/2006 by Danny Lipford

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There is no doubt that staying cool is on the top of most people’s minds this time of year … but what if your air conditioner is not working properly, or worse - you don’t have one at all. Whether you have an existing unit in need of some upkeep or are in the market for a new one, we have some tips and helpful information for you.

Properly Maintain Your AC Unit for Maximum Performance

By performing regular maintenance on your air conditioner, you will not only extend the life of the unit, but your home will remain at a comfortable temperature without an uncomfortably high energy bill.

Maintaining Window, Mobile and Through-the-Wall Units

If you have window units, the most important maintenance step is to change the air filter regularly. Most window units have a simple filter in the front grill area. Clean it once a month during cooling season and be sure to replace it when it has any holes or just appears worn. Also, be sure to clean the air conditioner properly by vacuuming around it to remove any dust and dirt that will clog up the unit and cause it to not work properly.

During the off season, if possible, take the unit out of the window and store in a dry location. If you must keep the unit in the window, be sure to cover the part that is exposed to the outside.

Maintaining Central Units

For central air conditioning units, the single best way to keep yours working properly year after year is to have it serviced by a trained professional. They will take care of the many items related to maintaining the unit and be able to perform any necessary repairs or “tune-ups”. Beyond that, be sure to keep the unit outside free from leaves and debris by raking around it and spraying off the unit with water. And make sure, above all, to change the filter several times per season.

If your air conditioner is older than 12-15 years and has ceased to operate properly, it may be time to purchase a new unit.

Choosing A New Air Conditioner

When it comes time to purchase a new air conditioner, as always, a little homework can not only save you headaches in the long run, but also ensures that you will get the best unit for your needs and will keep your energy costs to a minimum.

There are various types of units to choose from: window, mobile, through the wall and central. With each type there are many brands to choose from, factors to consider and additional features available. See our tips below and also visit the various websites for additional information.

Window Units

When choosing a window unit the most important factor is the size of the room you wish to cool and the number of BTU’s* of the unit you choose. For a quick guide to the correct size unit follow the guide below.

• 12×12 room - 5,000 BTU unit
• 16×16 room - 7,000 BTU unit
• 20×20 room - 10,000 BTU unit
• 24×24 room - 14,000 BTU unit

For a more comprehensive approach visit Consumer Reports’ website and see their worksheet.

In addition to the BTU’s, make sure the unit has an EER* of at least 11, an EnergyStar label and consider additional features such as noise (or lack thereof), air flow, permanent or reusable air filters, timers, various speeds and remote controls. For more information on top rated energy efficient air conditioners see links below.

Mobile Units

Basically a window unit on wheels, portable air conditioners are one of the newest types. While they do have an exhaust tube that must be vented out somewhere, they are truly portable in the sense that they require no permanent installation. Most come with a “window venting kit” that allows you to prepare a window for the exhaust tube.

When choosing a mobile unit, consider many of the same factors you would with a window unit. These units are ideal for an area in your home that needs either additional cooling or is not usually occupied.

Through The Wall Units

These type of units are typically what you would find in a hotel room and are excellent for an extra large room, apartment with an open plan or a remodeled garage. They can offer the benefit of both heating and cooling, functioning primarily as an extremely large window unit. In addition to considering BTUs, EER, etc, also consider the size (if any) of the existing sleeve. Look for a though the wall unit in standard sizes to fit previous openings.

Central Air Conditioners

When it comes to choosing a central air conditioning unit, there are many factors involved, such as the size of your home and the amount of windows and insulation contained in your home. The single best choice you can make is to choose a reputable air conditioning contractor who will determine the correct system for your home. As with any contractor, check references, ask questions about warranties (limited vs. extended etc) and of course get several comparable bids.

Once you have selected a contractor, they will determine the correct size and type of unit for your home by conducting a “manual J”. This evaluation ensures that they don’t choose a central air conditioner that is either too large or too small.

The rating used to choose a central air unit is called SEER* - Seasonal Energy Efficiency Rating. The higher the SEER the better. The current national efficiency standard for SEER is 13, but that is the absolute minimum. Look for anything over 13, and keep in mind that the higher the SEER rating the more efficient your unit needs to be. Bottom line - purchase an air conditioner with the highest SEER your money can buy.

Seasonal Energy-Efficiency Ratio (SEER)

The seasonal energy-efficiency ratio (SEER) rates how many Btu an air-conditioning unit will remove for each watt of electricity consumed. The higher the SEER, the less you spend on operating costs. Federal law mandates a minimum SEER of 10 for all new air-conditioning units.

Tonnage

An air-conditioning ton equals 12,000 Btu per hour. That means a three-ton air conditioner can remove about 36,000 Btu of heat per hour from your home.

Annual Fuel-Utilization Efficiency (AFUE)

The annual fuel-utilization efficiency estimates how much heat a unit delivers for every dollar spent on fuel. The higher the AFUE, the lower your heating bills.