It’s time. You’re heading to the market for a window aircon. But wait…
Do you really know how to choose the right size window air conditioner? There’s nothing more frustrating than a window air conditioner that can’t keep up. Imagine battling a 40°C Adelaide afternoon, and your lounge feels like an oven because your aircon is too small. Or worse, your oversized unit keeps stopping and starting, wasting electricity and hiking up your bills.
If your air conditioner is too small, it will struggle to cool the room. It’ll hum loudly, eat up energy, and yet barely push the heat out. You’ll see it in your energy bills: high numbers, low comfort. Get a unit that’s too big, and it’s the opposite problem. It cools the room too quickly. That sounds great until you realise the air is cold but muggy. No time for proper dehumidifying. You’ll be stuck with chilly, damp air that feels anything but fresh.
At REQ Refrigeration and Air Conditioning, we get this right the first time. Our team doesn’t just slap a one-size-fits-all AC solution on your home. We measure, calculate, and match you with the perfect cooling system.
Whether you need a small window AC for a snug bedroom or a more powerful air conditioner for a bustling lounge room, we’ve got the tools and know-how.
Table of Contents
- 1 Understanding Air Conditioner Sizing Terminology
- 2 Assessing Your Home's Cooling Needs
- 3 Selecting the Right Type of Air Conditioner
- 4 Keys to Optimal Air Conditioner Performance
- 5 Getting Professional Help for Sizing and Installation
- 6 Frequently Asked Questions
- 6.1 How do I determine what size window air conditioner I need?
- 6.2 Is it better to oversize or undersize a window AC?
- 6.3 What size room will a 7.1 kW air conditioner cool?
- 6.4 Do portable air conditioners and window air conditioners have the same cooling capacity?
- 6.5 Where are Mitsubishi air conditioners made?
- 6.6 Are Mitsubishi air conditioners good?
Understanding Air Conditioner Sizing Terminology
When choosing the right size air conditioner for your home, it’s essential to have a clear understanding of the various sizing terminologies. In this section, we will discuss the relationship between kilowatts and cooling capacity, the Australian Government’s Energy Rating Label scheme, and how an air conditioner’s effectiveness is calculated using the coefficient of performance.
The Australian Energy Rating Label
The cooling capacity of an air conditioning system is measured in kilowatts and represented by a rating on the unit. This rating indicates how much heat the air conditioner is capable of removing or adding to the room in one hour. It is typically listed as a range to better account for variations in room sizes, ceiling heights, room orientations, and other factors that may impact the estimate. By contrast, the power input of an AC unit refers to the amount of electricity it consumes while running. It is typically lower than the kW rating for the system’s heating and cooling capacity.
Fortunately for us Australians, much of the complexity of determining an efficiency AC system is neatly summarised in the Energy Rating Label.
Example of the Energy Rating Label, as featured on the Australian Government’s consumer Energy Rating guide.
The Energy Rating Label is a powerful tool at the hands of prospective buyers, and can not only help you understand the energy expenditure and saving opportunities presented by a particular system, but will also indicate how efficiently the system will run in your climate.
Coefficient of Performance
Long formulas and confusing calculations can be off-putting, but luckily for us, one of the most reliable ways of measuring the performance of an air conditioner is by using a simple calculation called the “coefficient of performance”. The coefficient of performance is simply the ratio of the heat delivered or removed by the AC to the energy consumed to perform this task. You can easily calculate this yourself by dividing the heating or cooling output by the energy input. The higher the COP, the more efficient the system, and the more likely it is to give you a bang for your buck!
Assessing Your Home's Cooling Needs
Several crucial steps are involved in determining the cooling and heating needs of your home. In this section, we provide an in-depth overview of each, enabling you to make informed decisions when selecting the right system for your home or business.
Calculating the Room’s Dimensions
Begin with measuring the size of the room or area you want to cool in squared metres. To calculate the room’s size, multiply the its length by its width. This will give you a better idea of the air conditioner’s required cooling capacity, measured in kilowatts per hour.
Climate and Humidity Factors
Climate and humidity also play a significant role in determining the right size air conditioner for your home. In hotter and more humid areas, you may need an air conditioner with a higher kw rating than a home in a cooler, drier climate. Keep in mind that window air conditioners often remove humidity in addition to cooling, which is especially important for regions with high humidity levels.
Insulation Quality
The quality of your home’s insulation will impact the effectiveness and efficiency of your air conditioner. Well-insulated homes can maintain comfortable indoor temperatures more easily and may require a smaller air conditioning unit. On the other hand, poorly insulated homes may need a larger air conditioner or additional insulation upgrades to achieve the desired temperature.
Sun Exposure and Window Considerations
Your home’s sun exposure can affect the size of the air conditioner needed as well. Rooms with large windows or those that receive direct sunlight may require a more powerful air conditioner to maintain a comfortable temperature. Consider factors such as the orientation of the room, whether it faces East, or West, the window size, and presence of shade when determining the cooling needs of a specific area. To account for sun exposure and window considerations, you may need to adjust the kilowatt rating of the selected air conditioner accordingly.
Selecting the Right Type of Air Conditioner
Choosing the right type of air conditioner for your home is important for effective cooling and energy efficiency. This section will explore three common types: reverse cycle ducted air conditioners, split system air conditioners, and evaporative air conditioning.
Ducted Reverse Cycle Air Conditioners
Ducted reverse cycle air conditioners provide both heating and cooling functionalities. They are suitable for climates where both winter and summer temperatures are extremes. These systems are integrated throughout an entire building, and present unique energy-saving opportunities due to their ability to regulate climate in ‘zones’ and their use of heat exchange rather than direct heating or cooling.
For smaller rooms or supplemental cooling, window air conditioners and portable air conditioners can be used as a reverse cycle option. However, for larger spaces or whole-home solutions, ducted reverse cycle air conditioners are the optimal solution.
Split System Air Conditioners
Split system air conditioners are composed of an indoor and outdoor unit that work together to provide cooling or heating. They are a popular choice for single rooms, apartments, and smaller homes. The benefits of split systems include easy installation, and individual room control.
A subtype of split-system air conditioners is the multi-split system, which allows several indoor units to be connected to a single outdoor unit. This option is particularly suitable for homes or apartments where multiple rooms require cooling or heating.
Evaporative Air Conditioning
Evaporative air conditioning is an eco-friendly and energy-efficient cooling solution that suits dry and hot climates. These systems work by cooling outdoor air through evaporation, which is then circulated throughout the home. Additionally, they keep the air humidified, providing extra comfort during hot and dry periods.
Central air conditioning systems can incorporate evaporative cooling, allowing your entire home to benefit from this energy-saving method. However, evaporative cooling may not be efficient in humid climates, as the cooling effect is reduced when the air is already saturated with moisture. This is becoming especially relevant in South Australia, where a once dry climate is becoming increasingly humid, limiting the effectiveness of this once-potent cooling solution.
Keys to Optimal Air Conditioner Performance
Optimal air conditioner performance depends on several factors. To ensure maximum efficiency, comfort, and the longevity of your AC unit, consider the following subsections:
Energy Efficiency
Energy-efficient air conditioners operate with less power consumption, reducing your monthly energy bills. Look for models with a high Energy Rating Label, as such advanced devices are designed to reduce greenhouse emissions and save electricity, benefiting both the environment and your wallet.
Noise Level
Consider the noise level of the air conditioner, as a quieter unit promotes a more comfortable and restful environment. AC noise levels are measured in decibels (dB), and a lower number indicates a quieter operation. Look for models with a noise range of 50-60 dB for regular use or less than 50 dB for bedrooms.
Warranty and Reliability
A reliable air conditioner is crucial for hassle-free performance. Make sure to check the warranty offered by the manufacturer, as it signifies their confidence in the product’s durability. A comprehensive warranty covering both parts and labour is desirable for added protection.
Maintenance and Regular Cleaning
Regular cleaning and maintenance of your air conditioner have a major impact on its performance and lifespan. Ensure the filters and coils are clean and free of debris, and invest in professional maintenance checks at least once a year. This proactive approach will improve energy efficiency and prevent potential breakdowns.
By considering these factors, you’ll be better equipped to find the right size air conditioner for your home with optimal performance, providing a comfortable and energy-efficient environment for years to come.
Getting Professional Help for Sizing and Installation
When it comes to choosing the right size air conditioner for your home, getting professional help for sizing and installation can save you time and money in the long run. In this section, we will discuss the importance of hiring an air conditioning contractor, understanding Manual J calculations, AC installation services, and budgeting.
Hiring an Air Conditioning Contractor
Hiring a professional air conditioning contractor should be your first step in this process. They will have the expertise to assess your home and provide recommendations based on factors such as size, insulation, and climate. Make sure to hire a licensed and certified contractor by checking their references and reviews.
Budgeting
Understanding your budget is crucial when selecting the right size air conditioner and hiring professional services. Consider factors such as the unit’s cost, installation fees, and potential long-term energy savings. Keep in mind that investing in an appropriately sized air conditioner will lead to lower energy bills and a comfortable living environment, which can ultimately save you money in the long run.
Frequently Asked Questions
How do I determine what size window air conditioner I need?
Start by measuring your room’s square footage (length × width). Then, match that to the cooling capacity (in BTUs) needed. A small bedroom might need a 2.5 kW air conditioner, while an open lounge room could demand 7.1 kW. Ceiling height, insulation, and window size also matter when figuring out how to choose the right size window air conditioner.
Is it better to oversize or undersize a window AC?
Neither is ideal. An oversized unit cools too fast without removing humidity, leaving rooms damp and uncomfortable. An undersized air conditioner struggles to keep up, running longer and pushing up energy costs. Aim for the right sized air conditioner based on your exact room and cooling needs.
What size room will a 7.1 kW air conditioner cool?
A 7.1 kW window air conditioner is perfect for large spaces, typically around 40 to 50 square metres. They're great for open-plan living rooms or family rooms with high ceilings. If your space gets direct sunlight or lacks insulation, you may need a more powerful air conditioner.
Do portable air conditioners and window air conditioners have the same cooling capacity?
Not quite. While both can cool a room, portable air conditioners generally have lower cooling capabilities compared to window units of the same size air conditioner. Window air conditioners usually offer better energy efficiency and cooling power for the room size they’re rated for. Always compare the air conditioner capacity and energy efficiency ratings before choosing.
Where are Mitsubishi air conditioners made?
Mitsubishi air conditioners are primarily made in Japan and Thailand. Mitsubishi Heavy Industries and Mitsubishi Electric, though separate, both maintain strict quality control, ensuring their air conditioners are built for durability, efficiency, and long-term performance.
Are Mitsubishi air conditioners good?
Yes, they are among the best. Mitsubishi air conditioners are known for their reliable performance, energy efficiency, and advanced features like quiet operation and smart climate control. At REQ, we recommend Mitsubishi units often because they consistently deliver top-notch cooling for Australian homes.
