In the scorching heat of Australia’s summers, insulation alone will not suffice. A reliable and efficient air conditioner becomes more than just a luxury; it’s a necessity.
History of Air Conditioning
It all began in the early 20th century when a young engineer named Willis Haviland Carrier invented the first modern air conditioning system in 1902. Carrier was working on a solution to control the humidity levels at a printing plant in Brooklyn, New York. His invention not only addressed the humidity issue but also had the unintended benefit of cooling the air.
The breakthrough came with the development of the “Apparatus for Treating Air” – the world’s first air conditioner which used a series of coils and fans to cool and dehumidify the air. Initially, air conditioning was primarily used in industrial settings and large commercial spaces to improve productivity and preserve products sensitive to heat and humidity.
The widespread adoption of air conditioning in homes and cars began in the 1950s and 1960s, marking a significant shift in the way people lived and worked. The availability of residential air conditioners made a profound impact on society, especially in places with hot climates.
Advancements in technology over the years has led to more energy efficient and environmentally-friendly air conditioning systems. Today, air conditioners are an integral part of modern life.
Importance of Air Conditioning
Air conditioning plays a significant role in improving comfort and quality of life:
Temperature control
Air conditioners regulate indoor temperatures, providing a comfortable environment regardless of external weather conditions. This is particularly essential in regions with extreme temperatures, ensuring people can work, live and sleep comfortably. Public spaces like hospitals, shopping malls and public transportation heavily rely on air conditioning to create a pleasant, safe and attractive environment for the people who use these facilities.
Reducing humidity
Air conditioning contributes to better indoor air quality by reducing humidity, preventing the growth of mould and mildew, and filtering out pollutants and allergens.
Preservation of goods and equipment
Air conditioning is essential for preserving the quality and longevity of goods, especially in food storage, pharmaceuticals and manufacturing. It prevents spoilage, degradation and damage to sensitive products and equipment.
As global temperatures rise due to climate change, air conditioning is becoming increasingly important. It helps mitigate the impact of heatwaves, especially on the elderly and those with pre-existing health conditions.
How Does an Air Con Work?
An air conditioner works on the principles of thermodynamics, utilising a cycle of evaporation, compression, condensation and expansion to remove heat from indoor spaces. Here’s a simplified explanation of how an air conditioner operates:
1. Evaporation
The process begins with the refrigerant (a chemical substance with a low boiling point) inside the evaporator coil. Warm air from the indoor space is blown over this coil by a fan. The heat from the air causes the refrigerant to evaporate, turning it from a liquid into a gas.
2. Compression
The now-gaseous refrigerant is then compressed by the compressor unit. Compression increases the temperature and pressure of the refrigerant, transforming it into a high-energy, high-temperature gas.
3. Condensation
The high-temperature, high-energy gas flows into the condenser coil located in the outdoor unit of the AC. Here, the hot gas releases its heat to the surrounding air and condenses back into a liquid state.
4. Expansion
The condensed liquid refrigerant then passes through an expansion valve, which rapidly decreases its pressure. This causes the refrigerant to cool down significantly, turning it back into a low-pressure, low-temperature liquid.
5. Heat dissipation
The cool liquid refrigerant returns to the evaporator coil, and the cycle repeats. As the refrigerant evaporates again, it absorbs heat from the indoor air, and the process continues until the desired temperature is reached.
This cycle of evaporation, compression, condensation and expansion effectively transfers heat from the indoor air to the outdoor environment, cooling the indoor space. The fan inside the indoor unit circulates the conditioned air throughout the room.
It’s worth noting that this process requires a closed-loop system, where the refrigerant continuously circulates through the evaporator, compressor, condenser and expansion valve. The efficiency of an air conditioner is influenced by factors such as the type of refrigerant used, the design of the system and the insulation of the space being cooled.
Types of Air Conditioning Systems
There are several types of air conditioning systems out there to choose from:
Split system air conditioner
This is the most common type, consisting of two main components – an indoor unit and an outdoor unit. The indoor unit contains the evaporator coil and air handler, while the outdoor unit houses the compressor and condenser coil. They are connected by refrigerant lines. A split system is ideal for cooling individual rooms or specific zones in a house or office.
Ducted air conditioning system
Ducted systems use a central unit to cool the entire building. Cool air is distributed through a network of ducts and vents installed in ceilings or floors. It offers a more discreet cooling solution as it will usually blend quite well with a white ceiling. This system is best suited for cooling large spaces or entire homes, with the flexibility to control temperatures in different zones from one place.
Window air conditioner
This is a self-contained unit installed in a window or a specially designed opening in a wall. It contains all the components in a single box, including the evaporator, condenser, compressor and fan. A window air conditioner is commonly used for cooling individual rooms, apartments or smaller spaces due to its compact design.
Portable air conditioner
These are similar to window units but portable. They include wheels for easy movement and typically feature a single hose or dual-hose system to expel hot air outside. A portable AC offers flexibility to cool different rooms as needed, suitable for spaces where permanent installation is not possible.
Packaged air conditioning system
All components of a packaged air conditioning system are housed in a single unit. This unit is usually placed outdoors or on the roof, and cooled air is delivered through ducts. This system is commonly used for commercial spaces or homes without sufficient indoor space for separate components.
Multi-split air conditioning system
A multi-split air conditioning system is similar to a regular split system but with multiple indoor units connected to a single outdoor unit. Each indoor unit can be controlled independently, allowing for different temperatures in various rooms. A multi-split system is ideal for cooling multiple rooms with individualised control, making it a versatile solution for homes or offices.
Geothermal heat pump system
Used since the late 1940s, a geothermal heat pump system utilises stable, underground temperature to exchange heat, providing both heating and cooling. It involves burying pipes or loops underground to transfer heat between the building and the earth. Known for energy efficiency, it is suitable for both residential and commercial applications.
What Size Air con Do I Need?
Choosing the right size air conditioner is important for optimal comfort and energy efficiency. Selecting an aircon that is too small may struggle to cool the space, leading to increased energy consumption and wear on the system. On the other hand, an oversized aircon may cycle on and off frequently, resulting in inefficient operation and higher energy bills.
According to Alliance Climate Control, to determine the cooling capacity your room needs, you can follow this formula (summarised):
- Measure the length and width of the room and multiply these dimensions. If you’re cooling multiple rooms, repeat this and then add all the totals together. Ensure the result is in square metres.
- Multiply the total area by a specific factor based on the ceiling height. For 2.4m, use 150 watts; for 2.7m, use 160 watts and for 3m, use 175 watts.
- The resulting number is an estimate of the wattage required to cool the room/s. To convert this to kilowatts, divide the wattage by 1,000.
This method provides a reliable estimate for determining the cooling capacity needed for your space. However, there are other factors to consider:
Insulation and sun exposure
Consider the level of insulation in the space and what its R-value is. Also review the amount of sunlight the room receives – well-insulated rooms and those with little direct sunlight will require less cooling. If an insulation installation is required, contact a reputable installer.
Occupancy and usage
The number of people in the room and the purpose of the space (e.g. home gym, kitchen, bedroom) influence the cooling load. Rooms with higher occupancy or heat-generating appliances may require more cooling capacity.
Consult with a HVAC professional
HVAC professionals have the expertise to perform a thorough analysis of your room or home. They can consider factors that may not be easily quantifiable and recommend the most suitable air con size.
Review manufacturer recommendations
Refer to the manufacturer’s specifications and recommendations for that specific air conditioning unit. Manufacturers often provide guidelines on the suitable room size for each model.
What Does an Air Con Installation Involve?
An air conditioner should be installed by a licenced air conditioning technician. To install an air con, a technician will generally follow these steps:
- Select a suitable location
- Install a mounting bracket
- Prepare the window or wall opening
- Secure the air conditioner
- Connect electrical wiring
- Seal gaps
- Test the unit.
Best Place to Install an Air Con in a Room
Where the air conditioner is installed in a room significantly impacts its performance, efficiency and overall comfort. Here are some considerations for determining the ideal location:
Centred on the room
Have the air conditioner installed in a central location within the room. This helps ensure even distribution of cool air throughout the space. Avoid placing it in a corner, as it may struggle to reach all areas effectively.
Away from heat sources
Keep the air conditioner away from heat-generating appliances, direct sunlight or other sources of warmth. Placing it near such sources can make the unit work harder to cool the space and reduce overall efficiency.
Avoid obstructions
Ensure that the airflow from the air conditioner is not obstructed by furniture, curtains or other objects.
Proximity to electrical outlets
Install the aircon close to electrical outlets to avoid the need for extension cords. Using extension cords may not provide a stable power supply.
Height considerations
For window or wall units, it’s recommended to have them installed at a height where the cool air can disperse effectively.
Consider zoning needs
If you have a ducted or multi-split system with zoning capabilities, strategically position the indoor units to match different zones. This allows for customised temperature control in various areas of the room or building.
For all of the above considerations, a HVAC technician will be able to give you professional advice that suits your house and specific requirements.
To ensure the cooled or heated air doesn’t just escape, make sure you’ve got wall, underfloor and ceiling insulation installed, and even consider double-glazing your existing windows to properly seal the room.
Feel free to contact Amelior Insulation if you need any insulation advice or assistance.
Best Air Conditioner Brands
Below is a list of some of the best air conditioning brands and what they are known for:
- Mitsubishi Electric (high-quality split system and ducted air conditioners)
- Daikin (split systems, ducted systems and VRF technology)
- LG (split systems, window air conditioners and multi-split systems)
- Panasonic (split systems and innovative technology)
- Fujitsu General (split systems and ducted air conditioners)
- Carrier (packaged air conditioning and geothermal heat pump systems)
- Trane (packaged air conditioning systems and reliability in commercial settings)
- De’Longhi (portable air conditioners).
Are All Air Cons Energy Efficient?
Not all air conditioners are equally energy efficient. Air conditioning can cost anywhere between $0.30 and $1.50 per hour, depending on the room and system. Some factors that will influence efficiency include:
- Energy Efficiency Ratio (higher = more energy efficient)
- Seasonal Energy Efficiency Ratio (higher = more energy efficient)
- Inverter technology
- Energy Rating Label (more stars = more energy efficient)
Ensure you take all of the above factors into account when choosing an air con for your energy efficient home.
Air Conditioner Maintenance
Proper maintenance is essential to ensure the efficient and long-term operation of an air conditioner. So, how do you clean and maintain an air con?
1. Read the manufacturer's manual
Always refer to the manufacturer’s manual for specific maintenance instructions and guidelines tailored to your air conditioner model. Avoid taking risks that could potentially result in expensive repairs.
2. Turn off the power
Before performing any maintenance, turn off the power to the air conditioner for safety.
3. Clean or replace the air filter
The air filter traps dust, dirt and other particles, preventing them from entering the indoor unit. Clean or replace the filter regularly (usually every 1-3 months, depending on usage).
- For reusable filters: Remove the filter and clean it with a soft brush or vacuum. Rinse it in warm water if necessary, but make sure it’s completely dry before reinstalling.
- For disposable filters: Replace them with a new filter following the manufacturer’s recommendations.
4. Clean the coils
The evaporator and condenser coils can accumulate dirt over time, reducing the system’s efficiency. Use a soft brush or vacuum to clean these coils gently. If the dirt is persistent, consider professional cleaning.
5. Check and clean the drain line
The drain line allows condensate to flow out of the system. Over time, it can become clogged. Inspect the drain line and, if necessary, flush it with a bit of distilled white vinegar. Ensure proper drainage to prevent water damage.
6. Inspect the fins
The aluminium fins on the evaporator and condenser coils can become bent, affecting airflow. Use a fin comb or a gentle brush to straighten any bent fins.
7. Inspect the refrigerant lines
Check the refrigerant lines for any signs of leaks or damage. If you notice issues, contact a professional technician for repairs.
8. Clean the outdoor unit 1-2 times per year
For split systems or window units with an outdoor condenser unit, ensure that the area around it is clear of debris and vegetation. Use a soft brush or vacuum to remove dirt and debris from the fins.
9. Ensure proper insulation
Check the insulation on the refrigerant lines. Replace any damaged or missing insulation to maintain energy efficiency.
10. Schedule professional maintenance
While you can perform basic maintenance, it’s advisable to schedule professional maintenance annually.
Regular maintenance not only keeps your air conditioner running smoothly but also helps improve energy efficiency and indoor air quality.
AC Issues You May Come Across
Air conditioners can experience various issues over time, ranging from minor inconveniences to more significant malfunctions. Some common issues you might encounter with an aircon include:
Leaking water
Water leakage from the indoor unit can result from a clogged or damaged drain line, a dirty or frozen evaporator coil, or improper installation. If you notice water pooling around the indoor unit, it’s essential to schedule a service to identify and address the root cause.
Foul smells
Unpleasant odours may stem from mould or bacteria growth on the evaporator coil, a clogged drain pan or dirty filters. Persistent or strong odours warrant professional attention. Regular cleaning and maintenance can help prevent this issue.
Inadequate cooling
Insufficient cooling can result from dirty or blocked filters, low refrigerant levels, a malfunctioning thermostat or issues with the compressor. If the air conditioner fails to cool the space adequately, especially after cleaning or replacing the filters, professional service is necessary to address the underlying problem.
Noisy operation
Unusual or loud noises may indicate problems with the fan, compressor or other internal components. If the noise persists or is particularly loud, schedule a service to prevent further damage and ensure efficient operation.
Frozen evaporator coil
Reduced airflow or low refrigerant levels can cause the evaporator coil to freeze, hindering the cooling process. If you notice ice buildup on the coil, turn off the system and contact a technician to inspect and resolve the issue.
Electrical issues
Problems with the electrical components, such as a malfunctioning thermostat, capacitor or wiring issues, can disrupt the operation of the air conditioner. As with any electrical work, book in a service with a certified electrician to prevent safety hazards and further damage.
Short cycling
Short cycling occurs when the air conditioner turns on and off frequently, potentially due to issues with the thermostat, refrigerant levels or a malfunctioning component. Continuous short cycling can strain the system and increase energy consumption.
Regular maintenance (and servicing if necessary) can help prevent the above issues.
Smart Features of a Modern Air Con
Modern air conditioners come with a variety of features to improve comfort, energy efficiency and convenience. Some of these include:
- inverter technology for precise temperature control and efficiency
- Wi-Fi connectivity for remote control
- programmable thermostats
- quiet operation
- multi-speed fans
- filter alerts
- air quality sensors
- humidity control
- dual or multi-zone cooling
- motion sensors
- self-cleaning functions
- variable refrigerant flow (VRF) technology
- heat pump functionality
- ductless mini-split systems
- the use of eco-friendly refrigerants.
How Much Does an Air Conditioner Cost?
The cost of an air conditioner in Australia can vary widely based on several factors, including the type of air conditioner, its capacity, energy efficiency, brand and installation requirements.
For a split system air conditioner, prices typically start from around $600-$1,500 for a basic single-room split system, and they can go higher for models with advanced features or higher cooling capacities.
Ducted systems can range from $5,000-$15,000 or more, depending on factors such as the size of the house and the number of zones.
Window units are generally more affordable, with prices ranging from $300-$1,000.
Portable units typically cost between $400-$1,500, determined by factors such as cooling capacity and energy efficiency.
The information provided in this article is for general guidance only and does not replace professional advice. Readers are encouraged to consult with qualified HVAC technicians for personalised recommendations.