- — 25 October, 2007 14:50
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- Size it up
- Types of air conditioners
- Inverter systems
- Reverse cycle
- Costs and energy efficiency
- FAQs: Air Conditioners
- Shopping checklist: Air Conditioners
FAQs: Air ConditionersWhat size unit should I purchase? Air conditioners are rated in Kilowatts (kW). This is a measure of two factors: an air conditioner's output capacity (the amount of heat that will be removed (cooling) or added (heating) to the room/s in your house by the air conditioner); and its energy consumption (the energy the air conditioner uses per hour at rated capacity). Both these measurements are shown on the Energy Efficiency Rating label found on all air conditioners as Capacity Output kW and Power Input kW.
The amount of kW you will need depends on the size of the room you want to heat/cool and its heat load which is determined by environmental factors such as the amount of windows and sunlight in the room, weather conditions and what type of insulation you have. Generally, the bigger the area you have, the more kW you will need to service it. Many air conditioners list a suggested room size to match the kW rating. You should be prepared to discuss room size as well as insulation, windows and so on with the sales member. You may also wish to consider getting an air conditioner installer to measure your room's heat load and the required kWs needed to heat/cool it.
What is an inverter system? An inverter system lets your air conditioner alter the speed of its motors (compressors) in response to cooling demand. The result is a controllable and energy efficient system that is not only cheaper to run, but also uses a smaller power supply.
What is the difference between a split system and a package unit? A split system has an indoor and outdoor part that is connected together. They provide quieter and more efficient air conditioning than a single package unit. They work by placing the cooling parts of the air conditioner in the outside unit and then having one or two inside components that contain the fans. Generally, one outdoor unit can power two indoor units at the same time. A package unit requires no external components but has to be installed through a window or wall. These units are good for small rooms, but some people find them bulky and unattractive.
What is the difference between a split system and a multi split system? A split system has an indoor and outdoor part that is connected together. Meanwhile a multi split system has just the one outdoor part that is connected throughout the house through multiple indoor parts installed in each room. So while a split system powers up the one room, a multi split system powers up the whole house from one outdoor part. Is a cooling-only system better than a heating/cooling system? Cooling systems are not necessarily better than combined cooling/heating systems, but they are generally cheaper to buy. Air conditioners that can both heat and cool can save you money, too, because you don't have to purchase additional heaters.
Can I leave doors and windows open while operating the unit? You can leave windows and doors open, but it's not a good idea if you're trying to heat or cool your room. If you're trying to cool down a room, it's best to close curtains, blinds and windows during the hottest part of the day. This will keep your house cooler and prevent your air conditioner from having to work harder than it has to. Can units be turned sideways to fit into a small wall space? No. Like refrigerators, air conditioners contain oil and cooling fluids and must remain upright at all times. Turning an air conditioner will damage it. If your air conditioner has been placed on its side, you should put it upright and wait 24 hours before you plug it back in.
Can a home unit cause Legionella? Legionella is not something you can contract from domestic air conditioning. The majority of cases are caused by incorrect cooling tower maintenance. Cooling towers are used in commercial air conditioning to cool water condensers and in industries to cool recirculated water.
Are there filters that need to be changed in air conditioners? Yes.
How often will they need to be changed? You should inspect the air filters in your air conditioner twice a month to see if cleaning is necessary. Trapped particles in the filter can build up and block the airflow. This reduces the air conditioner's cooling ability and also causes frost build-up on the cooling coils. Most residential systems have disposable filters and these should be replaced with the same size filter as originally supplied. Permanent filters should be cleaned according to the manufacturer's instructions.
Should a thermostat be set to "auto" or "on"? Today, most air conditioners have an "auto" setting on the thermostat that makes the fan operate only when the temperature requires it. This is generally the most used and efficient setting because programmable thermostats maintain a steady temperature and reduce energy use by only working when needed.
Can I reduce energy usage while still using the unit? You can if you use it economically. If you close windows, doors, curtains and blinds, you can help your air conditioner cool a room more quickly. Air conditioners with inverters and "auto" settings are economical in power consumption because they automatically adapt and maintain the temperature you want.
Should outdoor units be covered in winter? Outdoor units are designed to withstand seasonal changes so do not need to be covered. The heat pumps inside the unit operate year round and if you cover them, it may cause damage.
If an outdoor unit needs replacing, should the indoor unit be replaced too? Generally it is a good idea to replace the entire system when a major component of the system fails to operate correctly and cannot be repaired. That's because air conditioning and heating units are designed to operate as a complete, matched system.
Can plants or shrubs be planted around an outdoor unit? Yes. However, make sure there is plenty of room around the outdoor unit so air can freely flow in and out of it. Without room for air circulation, the unit can overheat and damage itself. It's also a good idea to trim shrubbery and limbs back because they can cause damage if leaves or twigs are sucked into the outdoor unit.
What is the average life expectancy for heating/cooling units? The average life expectancy of an air conditioner is about 10 years. When the air conditioner starts having more problems that are not cost-effective to fix, it may be time to replace it.