Evaporative Cooling Vs Air Conditioning

Evaporative coolers and air conditioners are two of the most popular cooling solutions in Melbourne. Both are powerful cooling systems designed to make your home more comfortable during the warmer months. They do, however, have some significant differences that will impact which will be the best choice for your home. Understanding the difference between evaporative cooling and air conditioning is important as both are suitable for different climates and priorities. In this article we explain what evaporation cooling and air conditioning are, their differences, pros and cons, and how to decide which is best for your home.

What is Evaporative Cooling?

Evaporative cooling is a cooling system that uses the principle of evaporation to cool the air, reducing the temperature by about 10 degrees. In a ducted system, the evaporative cooler has a rooftop unit outside and internal duct system to distribute the cool air. Warm air is drawn in from outside, cooled down and then dispensed into each room via ducts. The fundamental process of evaporative cooling is the natural phenomenon where evaporating water absorbs heat from the air, and then pushes the cooler, moist air into the room. For evaporative cooling to work effectively, there must be adequate ventilation. Doors or windows need to be open for constant air circulation and to allow heat to escape and prevent moist air from accumulating. Evaporative cooling works in these stages:

1. Hot or warm air is drawn in from outside using the fan in the rooftop unit.
2. The air is forced over cooling pads in the evaporative cooler.
3. A water tank inside the unit keeps the cooling pads wet.
4. As the hot air flows over or through the pads, the water evaporates leaving cooled, moist air.
5. This cool air is distributed through ducts back into the rooms.

Pros and Cons of Evaporative Cooling

Pros

• Energy efficiency: Evaporative cooling is extremely energy efficient as the system uses around 50% to 75% less electricity than standard air conditioning systems. An evaporative cooler uses less electricity because it is a natural cooling system that relies on water evaporation to cool the air. The only parts of an evaporative cooling system that require electricity are the fan and water pump.
• Less expensive to run: Because evaporative coolers use less electricity compared to air conditioners, energy bills are reduced and they are less expensive to run.
• Simple installation: Installation of a wall unit is relatively easy and will keep costs down. A rooftop unit with a ducted system is a little more complex as the vents and pipes need to be fitted by a specialist. Its simpler design and fewer working parts mean it is still cheaper than a refrigerated air conditioning system.
• Environmentally friendly: As evaporative coolers work via a natural process that uses water evaporation instead of refrigerants, they are more environmentally friendly. In addition, the low energy consumption makes evaporative cooling a sustainable option.
• Low maintenance: Evaporative coolers are considered low maintenance compared to other air conditioning systems. Basically they just need the pads and tank cleaned and a regular check of the water level. A professional service should be performed every one to two years or if there is any sign of issues.
• Filter traps airborne irritants: When the air passes through the water pads, airborne irritants like dust and pollen are trapped. This is ideal for those with allergies or respiratory issues as mainly fresh, cool air is entering the home.
• Ideal for dry weather: Evaporative coolers are ideal for the type of hot and dry summers in Melbourne. A dry environment means there is not much moisture in the air which is the ideal conditions for evaporative cooling. As well as cooling a room, evaporative coolers add moisture to the air.

Cons

• Can use a lot of water: Evaporative coolers can use a lot of water, particularly in high humidity areas or when the fan is on full speed. In these conditions, an evaporation cooler may use up to 25 litres of water per hour.
• High humidity in the air: Because evaporative coolers add moisture to the air, they also add humidity which makes them less effective in humid areas.

Product Recommendations

Breezair Supercool

Image: Seeley International

The Breezair Supercool is a powerful, energy efficient evaporative cooler ideal for large spaces. Cooling capacity for the Breezair Supercool is 10.8kW, 11.6 kW, 14.3kW and 15.1kW. It is one of the world’s coolest, quietest and most energy efficient evaporative air conditioning ranges.

The Braemar Evolution LPQI Series

Image: Seeley International

The Braemar Evolution LPQI Series has various models with different cooling capacities from 8.4kW to 13.2kW. It has a low profile, streamlined design with curved louvres and MagiQtouch controller. It utilises advanced cooling technology with a larger active cooling pad to provide powerful cooling.

What is Air Conditioning?

Air conditioning is a cooling unit that uses refrigerants and chemicals to cool the air. While air conditioners come in a variety of types and sizes, they operate on the same principle. They provide cold air inside the home by removing the heat from the indoor air and returning cool air to the home. Most air conditioners work by refrigeration cycle which is based on the principles of thermodynamics and includes compression, condensation, expansion and evaporation. The four steps of the refrigeration cycle of air conditioning are:

1. Compression: The compressor turns cool, low pressure gas into hot, high pressure gas.
2. Condensation: The hot gas is cooled and turned into a high pressure liquid that releases the heat outside.
3. Expansion: The liquid passes through an expansion valve which cools the refrigerant and turns into a low temperature liquid vapour.
4. Evaporation: The cold liquid absorbs the heat from the indoor air and turns it into a cool gas which cools the home before returning to the compressor to repeat the cycle.

Different Types of Air Conditioners

There are two main types of air conditioners – split system and reverse cycle. While both follow the same basic principles of air conditioning using the refrigeration cycle, there are some differences.

Split System Air Conditioners

These cooling systems have an outdoor and indoor unit. The indoor unit is the wall mounted section which holds the evaporator coils. The outdoor unit is on the exterior of the home and houses the compressor, condenser and expansion valve. The indoor unit draws the warm air from the room to the outdoor unit, which is then processed and returned through the indoor unit to the home. Some split system air conditioners can provide both heating and cooling, and some are designed purely for cooling purposes.

Reverse Cycle Air Conditioners

A reverse cycle air conditioner provides both heating and is commonly a ducted system. The heating component relies on heat pump technology, while the cooling system uses the same refrigeration cycle as other air conditioners. The system works by extracting heat from the room, processing it through a central unit which cools the air and then distributes it via vents back into the home.

Pros and Cons of Air Conditioning

Pros

• Energy efficient: Split system air conditioners are known to be one of the most energy efficient cooling systems. They often use inverter technology to adjust the power consumption which can significantly impact energy savings. The type and size of the unit will impact its energy efficiency, however.
• Work in all climates: An air conditioner is ideal for both dry and humid climates. The cool air circulating back into the room is not filled with moisture and keeps humidity to a minimum.
• Indoor air quality is improved: The filter in the air conditioner helps to remove any dust and debris before the air reenters the home.
• Can provide heating and cooling: Air conditioners can provide both heating and cooling. Many have reverse cycle modes which use both a heat pump and refrigerant for year-round comfort.
• Security: Because doors and windows do not have to be open, an air conditioner ensures better security for the home and its occupants.

Cons

• Reliance on chemicals: Air conditioners rely on the chemical refrigerants in the cooling process. These can be harmful to the environment

Product Recommendations

Daikin Alira X Split System

The Daikin Alira X Split System is available in reverse cycle and cooling only. It has a cooling capacity of from 2.2kW to 7.1kW for reverse cycle and 2.2kW to 7.1kW for cooling only. This air conditioner is ideal for cooling a single room or a specific area of a home and are available in wall mounted or floor standing types.

Toshiba RAS-10BKV-A1 Split System Air Conditioner 2.5 kW

The Toshiba RAS-10BKV-A1 Split System Air Conditioner 2.5 kW is a reverse cycle, split system air conditioner, suitable for a standard bedroom. The split system boasts the Toshiba hybrid inverter which integrates two distinct compressor control modules for maximum energy efficiency.

Main Differences Between Evaporative Cooling and Air Conditioning

The main difference between evaporative cooling and air conditioning is that evaporative cooling uses water to cool and humidify the air, while air conditioning uses refrigerant. Air conditioning is more suitable for humid climates while evaporative cooling is perfect for drier conditions. We explore the main differences between evaporative cooling and air conditioning to help you decide which is most suitable for your needs.

Upfront cost

• Evaporative cooling: Evaporative cooling usually costs between $3,000 and $8,000 for the unit and installation. This cost depends on the size of the unit.
• Air conditioning: A reverse cycle ducted air conditioning system may cost between $7,000 and $14,000 for the unit and installation depending on the size of the unit.
• *Contact Simply Air for a quote.

Performance and efficiency

• Evaporative cooling: Evaporative cooling works well in hot, dry climates as the water can evaporate easily from the cooling pads in these conditions. They are extremely energy efficient as they only use electricity for the fan and water pump.
• Air conditioning: Air conditioners are ideal for all weather conditions because they cool the air to precise thermostat settings and do not rely on the outside environment. They do use substantially more electricity than evaporative coolers to power the refrigeration cycle.

Climate control

• Evaporative cooling: As this system relies on low humidity and puts moisture into the air, evaporative cooling is limited for climate control and is not able to regulate the indoor temperature as efficiently.
• Air conditioning: Air conditioning is excellent for climate control as it uses a refrigerant to cool the air and can maintain a set temperature regardless of the outside conditions.

Air quality

• Evaporative cooling: The air quality from evaporative coolers is excellent as the system circulates 100% fresh, filtered air inside the home.
• Air conditioning: Air conditioners circulate the same continuous air throughout the home so the air quality is not as good as an evaporative cooling system.

Eco-friendliness

• Evaporative cooling: Because evaporative coolers use less energy and do not rely on chemical refrigerants, they are the most eco-friendly cooling system.
• Air conditioning: Air conditioners provide more powerful cooling but use substantially more energy. Along with the use of harmful refrigerants, they can be less eco-friendly than evaporative cooling units.

Maintenance requirements

• Evaporative cooling: These are low maintenance units, requiring pad and tank cleaning and a professional service every one to two years.
• Air conditioning: With more complex components, an air conditioning unit requires yearly professional servicing including checks of the refrigerant, coils, filter and fan.

How To Decide Between Evaporative Cooling and Air Conditioning

To decide between evaporative cooling and air conditioning, consider these factors:

• Location and climate: Where you live and the amount of humidity in the air is the most important factor. Evaporative cooling does not work well in humid climates while air conditioning can provide consistent temperature control in this situation. Melbourne’s climate is ideal for evaporative cooling particularly in dry, hot summers where humidity is below 50%.
• Energy efficiency: If energy efficiency is important, evaporative coolers are a good option but will only be effective in non humid climates.
• Functionality: Air conditioners are a better choice for functionality with reverse cycle capabilities offering both heating and cooling. For those living in areas with specific winter and summer temperatures, air conditioners are an ideal choice.
• Cooling capabilities: Air conditioners offer consistent cool temperatures regardless of the outside conditions and are a good choice for those wanting a robust cooling system.

Air conditioners and evaporative coolers provide cooling solutions for hot summer days. When looking at a cooling system for your home, it is important to know the difference between the two to establish which is best for your needs. Our article explains the differences between air conditioning and evaporative cooling, pros and cons and how to decide between the two. Simply Air supply and install both types of units and provide custom home cooling and heating solutions.