Essential Guide to Choosing an Energy-Efficient Air Conditioning Unit

When it comes to keeping cool, choosing the right air conditioner makes all the difference. With rising energy costs, changing temperatures, and growing environmental pollutants impacting air quality, choosing the right system is more important than ever. 

At National AC Parts, we’re here to guide you through everything you need to know about energy-efficient air conditioning - from choosing the right system for your home to understanding the latest smart features - so you can stay comfortable and healthy, save money and reduce your environmental footprint.

Beyond the Star Rating: Defining Your AC Needs

Energy efficiency starts with your home and lifestyle. Before you focus on energy ratings, it's important to understand your home and your family's needs. Here are three important things to consider when choosing your ideal AC type.

Know Your Home and Lifestyle

1. Layout & Usage: Do you need whole-home cooling or single-room cooling? Do you have a single or multi-story home?

2. Location: Is your home in a high-traffic urban setting where filtration is key?

3. Health: Do family members have any health conditions that are affected by air quality, temperature or humidity? Like allergies or asthma.

   
   

Which AC System is Best for my Home?

Once you understand your home and lifestyle needs - it's time to marry it to the optimal air conditioning system. There are several types of air conditioning systems to choose from and we have broken them down to the most common types when considering the type of home and type of use.

Wall Hung Split Systems Cooling a single room or average-sized living space. The most commonly recognised AC system in Australia. Newer models boast high energy-efficiency ratings and health innovations like advanced filtration and UV light technology to eliminate unwanted airborne particles and bacteria.
	Multi-Head Systems A versatile solution for cooling up to 5 rooms with a single outdoor unit. Great for multi-room cooling and 2 storey home solutions - you can choose an indoor unit type that best suits each unique space. Prevents oversized or undersized applications which helps save on energy, performance, cost and comfort.
Ducted Systems Whole-home climate control - disperses air through ducts and into each room of your house. Most efficient solution for controlling indoor temperatures, humidity and air quality. Options for high-quality filter upgrades for optimal indoor air quality, ideal for asthmatics.

Getting the Right Size AC (It Really Matters!)

Choosing the right size air conditioner is really important for optimal performance and efficiency. A unit that is improperly sized could be over or under used costing you more in running costs and potential hefty repair bills.

Issue	Cause	Effect
Undersized	The unit is too small for the space.	Components are stressed, leading to failure, higher repair costs, and longer run times to reach the desired temperature.
Oversized	The unit is too large for the space.	Causes "short cycling" (unit turns on and off too frequently), resulting in uneven temperatures, high humidity, and potentially higher energy bills.

While there are a number of online calculators available for research like the Cooling Load Calculator offered by the Australian Institute of Refrigeration, Air Conditioning and Heating (AIRAH), or a general British Thermal Unit (BTU) Calculator, we always recommend speaking to an expert who understands not only the size of the rooms in your home and hight of the ceilings, but will also take into consideration;

• The orientation of the home for direct sunlight impacts,

• The construction of the home (ie. brick, weatherboard, insulated) for keeping in the heat or cool air, and

• Appliance impact in dedicated spaces like offices and media rooms that emit heat when in use.

What to do with all the information - first make a coffee and take 5!

Now we have considered and discussed with experts;

• Our home and lifestyle needs,

• The number of rooms we wish to heat and cool, and

• The size of AC that best meets our needs

it is time to overlap the type of AC and the size of AC into the Energy Rating Calculator for Consumers offered by the Australian Government.

This Energy Rating Calculator, is a fantastic tool to help consumers find and compare energy-efficient appliances. More importantly it uses the newly introduced Zoned Energy Rating Label (ZERL) star calculation rather than the old star rating we all have become used to.

Energy Rating Calculator for Consumers example by the Australian Government

Energy Ratings: What’s ZERL and Why It Matters

ZERL improves on the old star ratings by showing how an AC performs in three Australian climate zones (Hot, Average, and Cold) based on your postcode. It gives separate star ratings for both heating and cooling, plus estimated annual energy use based on the base tariff in your locality - this means you will know how efficient the unit could perform where you live.

The previous star rating stickers we would see on all home appliance's would take the average energy consumption across Australia. While this was helpful for standard appliance like a kettle or a dishwasher, home owners on the Southern Beaches of NSW use their air conditioning systems very differently than home owners in Northern Qld and therefore wasn't really offering a energy- efficiency rating.

Most importantly, the Energy Rating Calculator for Consumers will allow you to compare different brands recommended by AC Companies, friends and family, and your own research against each other - so you can make an educated decision before you start the purchasing process.

NEO Control Suite - Courtesy of ActronAir

Further Energy Saving Features to Look For

Modern air conditioners are packed with innovative technology to reduce energy consumption. In a cost of living crisis it is important to be conscious about how to maintain healthy indoor quality and climate control to suit your lifestyle needs without blowing the budget. Here are some of the best energy-saving features to look for:

• Zoning (Ducted Systems): This allows you to control the temperature of rooms via your ducted air conditioning system. Zoning gives the home owner complete control of airflow and temperature across the entire home, avoiding energy waste on empty rooms. It will also provide the ability to set temperatures lower or higher in certain rooms like offices that have computers that emit heat, or a child's bedroom that may need a slightly warmer temperature, without it impacting the majority of the home.

• Smart Controls: Features like WIFI, smart scheduling and energy-saving modes make your AC more efficient. You can set the temperature and time to start running, and the system will automatically run during that period. Alternatively, you can turn your AC on remotely using WIFI on the unexpected hot days. When teamed with solar panels, this allows you to heat or cool your home using solar power - cutting energy costs and providing you and your family an ideal temperature home when you return from school or work.

• Sensors (Ducted Systems): Room sensors for ducted air conditioning systems report the room temperature back to the master wall controller adjusting airflow to conserve energy while maintaining the desired temperature. Some Wall Split and Multi-Head Systems come with advanced features like proximity sensors and 'follow me' technology adjust settings based on occupancy, minimising over-usage.

How to Run Your AC Unit Efficiently

Congratulations on your air conditioning purchase! You will be glad you followed the tips and insights above but we aren't going to leave it all up to yourself after we have come this far together. We have listed below a few simple steps to help you save even more money and get the most from your new AC system:

1. Optimal Temperature Settings: Setting the right temperature is important for energy efficiency without compromising your comfort. Small changes can make a big difference. Canstar Blue published an article recently stating:

   
   

   “According to the Department of Climate Change, Energy, the Environment and Water, every extra degree of heating and cooling will increase your energy consumption by 5–10%” 

   
   

   • Cooling: Set the temperature between 24°C and 26°C for most efficient cooling.

   • Heating: If you have a reverse-cycle unit, set the heat to between 18°C and 20°C for efficient heating.

     
     

     💡 Tip: Use “Dry Mode” on humid days — it removes moisture and makes the air feel cooler without the need for aggressive cooling.

     
     

2. Reduce Drafts: Seal gaps around doors and windows to prevent conditioned air from escaping - but remember to regularly ventilate your home to keep the air fresh.

   
   

3. Regular Preventative Maintenance: Regular preventative maintenance is important for your unit's energy efficiency and longevity. Let's face it - your new air conditioning system can cost the same as a small car so you want to get the most out of your investment for as long as possible.

   • Keep it Clean:

     • Clean your filters every 3- 6 months

     • Change your filters every 12 - 24 months

     • Schedule a deep clean (Flush) every 2 years for wall split and multi-head systems with wall split indoor units.

     • Keep the outdoor unit clear of clutter, plants and debris

   • Service Your Unit:

     • Schedule regular servicing with your local qualified technician to keep your unit running at its best and to maintain your warranty.

Final Thoughts - So, is it Worth Upgrading my AC?

Absolutely! Upgrading to a modern, energy-efficient air conditioner is a smart investment that delivers both immediate comfort and long-term savings.

By understanding your home’s layout, climate, and lifestyle needs - and pairing that with the right technology - you can find a system that’s perfectly suited to you. With the right system and regular maintenance, you’ll enjoy reliable performance, cleaner air, and lower running costs for years to come.

Ready to Upgrade? 

Our team at National AC Parts can help you find the right energy-efficient. Call us on 1300 904 554 or email info@nationalacparts.com.au.