Both air conditioners and evaporative coolers can provide whole-house cooling. But which is the best option for your house?
We look at how the various systems work, how much they cost to install and run, how much energy they each use, and the benefits and drawbacks of each type of cooling.
What Exactly Is An Evaporative Cooler?
Evaporative coolers reduce air temperature by converting water vapor into cool vapor. This simple technique has been used for centuries: bronze-age frescoes depict slaves fanning jars of water to keep rooms cool.
What Is An Evaporative Cooler?
In a ducted evaporative cooler, a fan draws warm outside air through wet filter pads in a roof-mounted head unit. The warm air evaporates the water, resulting in cooled and humidified air that is circulated throughout the house via ducts and vents in the ceiling. Portable evaporative coolers are also available, but they aren’t particularly efficient.
What Is The Energy Consumption Of An Evaporative Cooler?
Because only the fan and water pump use energy, power consumption is generally low (200 to 400 watts). However, depending on the features and capacity, this can vary greatly, and there are domestic units that can draw up to 2kW or more.
However, because of their low power consumption, evaporative coolers have a limited ability to convert electrical energy into cool air. Air conditioners are far more effective at converting energy into cooling.
What Exactly Is An Air Conditioner?
Air conditioners transfer warm air from inside your home to the outside, cooling it to a temperature set by a thermostat. Because this mechanism is similar to that of refrigerators, they are also referred to as refrigerated coolers or heat pumps.
Air Conditioners Of Various Types
• Split-system air conditioners are the most popular. They have an outdoor compressor unit and one or more indoor air outlets.
• Portable air conditioners are single units that plug into a power outlet and can cool up to 20m2 of space. They use a duct to exhaust heat through a door or window.
• Wall/window air conditioners, which are typically installed in a window or an external wall, can cool rooms and open-plan areas up to 50m2. Smaller units can be plugged into a standard power outlet, but larger ones may require additional wiring.
• Reverse-cycle air conditioners can heat and cool your home all year long, eliminating the need for a separate heating system. Most air conditioners on the market are reverse cycle, and it’s worthwhile to purchase one because they’re more efficient and typically cost less than a unit that simply cools.
• Ducted air conditioning systems have a central unit, usually located on the roof, that is connected by ducts to air outlets and sensors in each room, as well as compressors located outside. They’re a good option for whole-home cooling, but they’re not cheap. Ducts, in general, deteriorate over time. After 10–15 years, you’ll be losing cool air to the roof cavity before it reaches your home.
How Much Power Does An Air Conditioner Consume?
The energy efficiency of various air conditioner models can be found on the energy rating labels of each system. These allow you to compare the relative efficiency of different units at full load, but you must still choose a unit based on your specific needs, such as room size, local climate, and outdoor unit location.
As for size increases, so does the star rating. There are now small to medium 6- or 7-star units available. Aim as high as you can afford as a goal.