Close Ad >>

Air Conditioners: From Maintenance to Buying New

By: Danny Lipford
Central air conditioner units

Central air conditioner units.

Staying cool is on the top of most people’s minds during the hot summer months. But what if your air conditioner isn’t working properly, or you don’t have one at all? Whether your existing AC is in need of upkeep or you’re in the market for a new one, read on for some helpful tips to keep you cool!

Maintain AC Units 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.

How to Maintain Window, Portable, and Wall AC 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.

Window Air Conditoner unit

Window Air Conditoner unit.

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.

How to Maintain Central AC Units

For central air conditioning units, the single best way to keep yours working properly year after year is to have it serviced annually by a trained HVAC 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 air filter inside the house every few months or more.

Choosing a New Air Conditioner Unit

If your air conditioner is older than 12-15 years, it may be time to purchase a new unit. When it comes time to purchase a new air conditioner, a little homework will ensure you will get the best unit for your needs and keep energy costs to a minimum.

There are various types of air conditioner units to choose from including window, portable, through the wall, and central. With each type there are many brands to choose from, size and energy ratings to consider, and additional useful features.

Wall mounted air conditioner unit with remote control

Wall mounted air conditioner unit with remote control.

The rating used to choose an energy efficient central air unit is called SEER (Seasonal Energy Efficiency Rating). The higher the SEER the number, 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 will be.

Terms you might hear when buying an air conditioner unit include:

  • Seasonal Energy-Efficiency Ratio (SEER): This rates how many BTUs 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 13 for all new air-conditioning units.
  • AC Tonnage: A cooling ton in an air conditioner equals 12,000 BTUs per hour. That means a three-ton air conditioner can remove about 36,000 BTUs of heat per hour from your home.
  • Annual Fuel Utilization Efficiency (AFUE): This estimates how much heat a unit delivers for every dollar spent on fuel. The higher the AFUE, the lower your heating bills.

Window Units

When choosing a window unit the most important factor is the size of the room you wish to cool and the cooling power, or BTUs, of the unit you choose. Here’s a general guide for window air conditioners based on room size:

  • 12′ x 12′ room: 5,000 BTU unit
  • 16′ x 16′ room: 7,000 BTU unit
  • 20′ x 20′ room: 10,000 BTU unit
  • 24′ x 24′ room: 14,000 BTU unit

For a more accurate measurement, use the Air Conditioner Sizing Calculator at Consumer Reports.

In addition to size, make sure the AC unit you buy:

  • Has an EER (Energy Efficiency Ratio) of 11 or higher
  • Carries the EnergyStar label
  • Has a low noise rating
  • Provides good air flow
  • Uses a permanent or reusable air filter
  • Has various speed settings
Different styles of portable air conditioner units

Different styles of portable air conditioner units.

Portable AC Units

Basically a window unit on wheels, a portable air conditioner uses an exhaust tube, which must be vented outside, to remove hot air from the room. They are portable in the sense that they don’t require permanent installation. Most units come with a window venting kit that allows you to prepare a window for the exhaust tube.

When choosing a portable air conditioner, 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 AC units are similiar to what you often find in a hotel room; and are excellent for large open rooms, one-room apartments, 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 the considerations above, keep in mind the size required for the wall opening.

Setting the digital thermostat on a central air conditioner

Setting the digital thermostat on a central air conditioner.

Central Air Conditioners

When it comes to choosing a central air conditioner, 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), and get several comparable bids.

Once you’ve selected a contractor, they will determine the correct size and type of unit for your home to ensure the air conditioner isn’t too large or too small for your home.

Further Information



Please Leave a Comment

14 Comments on “Air Conditioners: From Maintenance to Buying New”

You can follow comments to this article by subscribing to the RSS news feed with your favorite feed reader.

  • Raylin Sutter Says:
    August 31st, 2015 at 8:21 am

    This is so useful, thank you! My air conditioner is in need of repair probably due to overuse this summer. It is an older unit and it is about time anyways for a replacement. However, I am so glad that it lasted throughout the summer. I would really like to get another one that is long lasting. Which brand is known for being the most durable?

  • Suvojit Says:
    May 19th, 2015 at 4:18 am

    I am from Kolkata.
    I want to buy an AC for my house. Based on the following criterias can someone please advice me which Brand (Hitachi, Samsung etc), Star (5 , 3) and Volume (Ton) should i buy considering economical, worth of money,electric consumption,quality and offcourse service etc ?

    1>Area of room (length*width*height): 3.2*3.8*3.01 (Meters) OR 10.49*12.46*9.9 (ft) – Top floor (1st)
    2>Usage probability: 5 months (Max) and 5.5 hours (Max) in a day — In a year.

    It will be a great help if i get comments as i am not much aware of the calculation of electric consumption and overall idea on Ac.

  • Mike Krause Says:
    March 25th, 2015 at 12:40 am

    Summer is coming and I was thinking of installing air-conditioner at their homes. Thanks for sharing your information on air conditioning buying guide and maintenance. Specially the points mentioned in the article will help me cleaning it smoothly.

  • mike malone Says:
    January 12th, 2015 at 6:14 pm

    Inquiring on the average cost to have my 18,000 btu Ramsond a/c wall unit cleaned (has some mold on the plate). I would appreciate knowing the cost I will be expecting to pay for this service.

  • cristina Says:
    May 25th, 2011 at 11:14 am

    I have central A/C but its only one zone. Upstairs I have 3 bedrooms and its always warmer. I hate to waste the central air at night since I just need it to cool upstairs. I was thinking of getting a window air conditioner, but I don’t think it will cool one of the bedrooms because of where it is located. It can cool off 2. So that would mean I would have to get another small a/c for that 3rd bedroom. Would it be cost-effective to buy one average size a/c and one small a/c for night time only instead of runnning our central a/c? Plus I think it will cool it better since its a one zone and upstairs is always warmer then downstairs.

  • Michael Armato Says:
    December 4th, 2008 at 12:30 am

    Dear Sir,
    I am setting up a motor home and wish to place a window wall air conditioner inside the bus, the rear of the unit would extend to the out side of the bus wall and the remainder or the unit would be in an inclosure with four inches on either side of the unit, is this exceptable for air flow to the unit or not, I am not sure if a unit needs to have air flow around it or only on the rear, any help would be appreciated.

  • George Lee Says:
    September 9th, 2008 at 11:18 pm

    Would window air-conditioners installed on its side instead of its designed upright position due to window space restrictions function properly or not?

  • Joy Says:
    August 31st, 2008 at 11:30 am

    I have seen a system advertised on the Wether Channel that dosen’t require duct work. Right now we are using 2 window air conditioners & they work fine, but, I also know they are now as cost effective as centeral air. We are also getting older & putting them in & taking them out every season can be back breaking. Please let me know how well these work & where I can find a dealer in my area. We live in St. Pau MN.

  • Ted Randall Says:
    March 16th, 2008 at 5:59 pm

    Dear Danny,

    I was wonderding if it was a good idea to build a lean to to cover my a/c unit or build an actual cover that will cover that will cover the top, sides and front? I’ve looked on your website and am not able to find an answer to that question. Thank you for your help.

  • Will Krohe Says:
    January 15th, 2008 at 10:41 pm

    What types of house insulation are availble and illustrate to pros and cons of each?

  • John Cannamela Says:
    January 15th, 2008 at 7:07 pm

    A few other things to remember.
    The units seer rating may only be as good as the building its installed in.If the envelope is less than to be desired than the hi seer unit will not pay back as quickly as stated.It is as important to have the home checked for window,insulation and air infiltration.You may want to spend the money on insulation instead of the hier seer ,the cost offset could be the same or in most older homes better to insulate in the long run.
    John Cannamela

  • Ken Ramey Says:
    January 13th, 2008 at 10:51 pm

    Great information. Having to buy a new central unit in San Antonio this year. The effeciency is most important to me. Want to keep it clean and green as long as we can

  • Will Krohe Says:
    August 2nd, 2007 at 2:04 pm

    Great information….any ideas on the brands of Air Conditions and Furnaces to buy? List the best then lesser, etc…Thank you and keep us informed on all issues regarding maintaining a home….

    Will Krohe.

  • Art Pokorny Says:
    April 15th, 2007 at 12:43 pm

    how do you install a window air conditioner in an above door transom. How should it be supported, insulated and waterproffed?

We want to hear from you! In addition to posting comments on articles and videos, you can also send your comments and questions to us on our contact page or at (800) 946-4420. While we can't answer them all, we may use your question on our Today's Homeowner radio or TV show, or online at

Air Conditioners: From Maintenance to Buying New