Guide to Buying an Air Conditioner

Air conditioning choices made easy.

With such a large range of air conditioners available, choosing the one that suits you can be daunting. We break it down for you.

Simple Air Conditioner Choices

• Room size: Match the power of an air conditioner to the room size.
• Air Conditioning Type: Choose from central ducted, window units, split systems and portable. 
• Filters: Prevent bacteria and allergens from being recycled through the room.

Room Size vs. Air Conditioner Capacity

Match the air conditioning unit to the size of the room it's cooling. As a rule of thumb, the bigger the room, the more powerful an air conditioner will have to be to cool it:

• Underpowered air conditioners will have to work harder, wasting energy
• Overpowered air conditioners are an unnecessary expense

How Much Capacity Will I Need?

Air conditioners are rated by BTU (British Thermal Unit) and power output, in kilowatts (kW). To work out the approximate sized air con you'll need, apply this simple formula:

• Bedroom: 80 watts (0.080kW) per square metre (length by width). For example, a 16m² bedroom should need around 1.28kW of air conditioning
• Living room: 125 watts (0.125kW) per square metre. For example, a 30m² living room should require around 3.75kW
• Proximity to the kitchen and appliances increases a room's required cooling

Which Type of Air Conditioner?

• Ducted Air Conditioners: Cool multiple rooms through a large cooling fan, which sits outside and pumps cool air around the building through ducts, which are housed in the ceiling cavity.
• Window units: Mounted through a window or a wall. These are excellent for small rooms.
• Split system: The cooling unit is installed outside, with the fans mounted inside. Split systems are suited to cooling one or more adjoining rooms.
• Multi-split system: Utilising one outdoor unit, with multiple fan units inside to distribute the cool air throughout the house.
• Portable: Small, light and can be moved from room to room. They have a low power output, suited to small spaces –- apartments and renters.
• Evaporative coolers: Appear like cheaper versions of portable air conditioners, but do not use refrigerant technology. They work by drawing air past a special water-cooled filter system.

Technical Terms You Should Know

• Reverse cycle: The air conditioner internally reverses its operation to provide heating or cooling, as required.
• Inverter system: Constantly alters fan and motor speeds. This enables faster cooling of a room, and the air conditioner doesn't have to switch itself on and off to maintain a constant temperature.

Energy Efficiency

Check the energy efficiency labels. Cooling-only air conditioners have one blue band of stars to display energy consumption. Reverse cycle has two bands of stars -- blue to indicate consumption during cooling and red for heating.

• Manufacturers of inverter systems claim that they are 30 per cent more efficient during partial load.
• Is It Noisy? If you're considering an outdoor air conditioning unit, check the relevant noise level regulations. 
• Are Filters Necessary? Yes. Good air conditioning units will use filters to prevent bacteria and allergens being recycled through the room.
• It's important to clean the filter every few weeks.
• Some units have an indicator to show when the filter needs changing.

Positioning Is Important

• Avoid positioning the air conditioning unit on the side of the house that gets the most sun; this will cause it to be less efficient.
• For efficient cooling, mount the unit high in the room -- cool air sinks.

Installation

Do not attempt to install a split or ducted system without holding the appropriate licenses. This will also void you warranty.

Top Air Conditioner Brands

There are many great air conditioning brands to choose from, I think these three are some of the best on the market for residential units:
1.) Trane Air Conditioners: This company is more than 100 years old, includes the American Standard and General Electric brands and has revolutionized the way heating and air conditioning has been used in the United States. On their website, they claim "our systems and services have leading positions in premium commercial, residential, institutional and industrial markets; a reputation for reliability, high quality and product innovation; and a powerful distribution network." From my experience in the HVAC industry, I would say this holds to be true. They offer great products that are very reliable.
Trane offers four different efficiency units; Ultra, Super, High and Standard efficiency. The units offered by Trane have a 13 to 20 SEER rating. The more efficient the more expensive the unit but more you will save down the road on utilities. They have focused a lot on indoor air quality and noise reduction with their machines. Trane is a reliable brand name that will be at the top of the HVAC industry for a long time.
2.) Carrier Air Conditioners: This company has also been around for over 100 years and claims to have been the first to engineer the first air conditioner in 1902. On their website they say "Through our market-leading products and solutions, we are constantly striving to help people live more comfortable, healthy and productive lives" which I believe to hold true as they are in 170 different countries and have one of the largest HVAC product lines.
Like Trane, they have four main types of units: Infinity, Performance, Comfort and Base units. The four are separated by efficiency levels which can be directly measured by their SEER rating ranging from 15 to 21. Carrier focuses and tests their units for sound, durability and air quality. As Carrier says, they invented the air conditioner and I believe you can count on their units.
3.) Goodman Air Conditioner: This company has been around for over 60 years and focuses mainly on residential and commercial units. Unlike the two companies above, they have not expanded into refrigeration equipment. Goodman says "We remain focused on providing high-quality products at an affordable price, and protecting them with what we believe to be some of the best warranties in the industry" on their website. They are right, they sell more units in the US because of their affordability and warranties than another other HVAC manufacturer.
Unlike Trane and Carrier, Goodman doesn't break down their units by efficiency. They have seven main residential units, all with different SEER ratings ranging from 13 to 18. They focus mainly on their units affordability, durability, and optimum cooling comfort. All of their units have at least a five year warranty and some even have a lifetime compressor warranty. Goodman is a great brand for residential and commercial ac units, you cannot go wrong buying one.
4.) York Air Conditioner: This company was purchased by Johnson controls in 2005 making them the largest global provider of integrated products, systems and services in the buildings market. Although the York brand hasn't been around as long as the other three manufacturers listed above, they make a very durable and energy efficient product.
York breaks their units down by three main types; Affinity, LX and Latitude models ranging from 13 to 18 SEER. York has concentrated on building quality residential machines that you can count on for quiet, trouble-free service and economical operation. York may not have the number of years in the industry as the other three brands mentioned here but when you buy a York air conditioner, you know you will have a machine that will last as long as any unit on the market.