The Ultimate Guide to Buying an Air Purifier

You know you want to buy an air purifier, but how do you determine the best one? To help you, we've included everything you need to know as a buyer to ensure you get the best air purifier for your needs.


The quality and size of the filters in your air purifier directly determine how effective your system is in filtering out the particles and pollutants in the air. To ensure you are well informed, here is everything you need to know about filtration.

What is a HEPA filter?

HEPA stands for High-Efficiency Particulate Air filter, and as the name suggests, it's an air filter designed to remove fine particles from the air. Specifically, a true HEPA filter can capture at least 99.97% of particles that are 0.3 microns in diameter or larger.

HEPA filters are highly effective at removing fine particles from the air, which can be particularly beneficial for those with allergies or respiratory issues. They can trap pollen, pet dander, dust mites, and even bacteria and viruses, making them an ideal choice for anyone concerned about indoor air quality. Additionally, HEPA filters are typically long-lasting and require minimal maintenance, which makes them a convenient and cost-effective solution for maintaining clean air in your home.

You can learn more about INOVA medical-grade HEPA filters here. For a complete list of what our HEPA filters remove from the air, click here.

What is an Activated Carbon filter?

Activated carbon filters contain carbon that has been treated with oxygen to open millions of tiny pores between the carbon atoms. This means that the carbon has a vast surface area, allowing it to capture and hold many pollutants.

As the air moves through the filter, the carbon captures the pollutants and absorbs them into its pores while clean air passes through. The pollutants that the filter captures include volatile organic compounds (VOCs), smoke, chemicals, and odours.

The more activated carbon you have within your air purifier the better the filtration would be. INOVA air purifiers have the largest amount of activated carbon filters on the market, ranging from 2.4-6kgs.

You can find out more about INOVA Activated Carbon filters here. For a complete list of what our Activated Carbon filters remove from the air click here.

When do I need to replace filters?

To ensure your air purifier continues to operate effectively and efficiently, it’s important to replace your filters regularly. We estimate that Pre-Filters should be changed every 6 months, carbon filters should be changed every 1-3 years and HEPA filters should be changed every 3-5 years.

For more information on how to replace our filters, check out our filter maintenance guide.


Fans are an important but often overlooked consideration when choosing an air purifier. EC fans are a newer type of fan that provides you with greater benefits than Traditional AC fans, making them the optimal choice. These benefits include:

  • Energy efficient – Use less energy, so are more cost-efficient.
  • Better performance – Advanced technology improves overall air purifier performance.
  • Longer life span – High-quality materials make them a more durable option.
  • Quiet operation – Designed to operate quietly, making them ideal for bedrooms and other quiet spaces.
  • Improved airflow – Provide greater air flow than traditional AC fans.

You can find out more about the benefits of EC fans over Traditional AC fans here.

System size

inova de20 and e8 models side by side

Wondering if size matters when it comes to your system? The answer is a resounding yes! The bigger the system, the bigger the filter (well, at least it should be!). The bigger the filter, the better the filtration – and the longer your system will last.

At INOVA, we manufacture our filters with the largest activated carbon filters on the market. Our E8 model includes 2.4kgs, and the E20 series contains 6kgs, making them highly effective in removing smoke and gas from the air.

You can find out more about the importance of your filter size here.

Questions to ask to find the best air purifier for you

To help you find the best air purifier for your needs, there are some key questions you should ask while shopping around. To help you, we've outlined these below.

What do I need to filter from the air?

How large is the space I need the air purifier to operate in?

What are the running costs of the air purifier?

What is the operating noise level?

What material is the air purifier manufactured from?

What warranty does the air purifier come with?

When it comes to INOVA air purifiers, there’s no comparison.

Traditional Air Purifiers

INOVA Air Purifiers

Less than 99.97% efficiency and HEPA filters that don’t meet H13 medical grade certifications*. Certified, guaranteed medical-grade efficiency of 99.97% @ 0.3 Microns. We deliver cleaner air with more effective dust and allergen removal across every purification setting.
No seals on filters. Sure Seal™ airtight seals on all filters. Benefit from zero leakage as all air passes through the filter, not around it, delivering guaranteed efficiency.
No pre-filters. Large, efficient pre-filters that extend the lifespan of HEPA and activated carbon filters. Save money with lowered operating costs.
Reduced quality plastic construction that results in noise and vibrations. All-steel manufacturing that’s designed for whisper-quiet performance suitable for all sleep environments.
Unsuitable for 24-hour operation. Unique German-engineered motors that achieve energy-efficient 24-hour operation, removing the risk of overheating and providing clean air protection around the clock.
Costly energy consumption and ongoing running costs. The lowest energy consumption rates relative to airflow and filtration efficiency. Delivers reduced running costs and a minimised environmental impact.
Ineffective in the amount of air they can filter. High-capacity fans filter a higher rate of air per hour, providing cleaner air in large and small areas alike.
A one-size-fits-all approach with no ability to customise filters. Customisable purification solutions with interchangeable filters, allowing the targeting of high-capacity dust, allergen and chemical removal. Higher quality of air purification through a customised filter solution for the needs of your environment.
Small, activated carbon filters that result in inadequate chemical removal. More activated carbon used per filter than any other residential air purifier (kilograms compared to grams!) resulting in the highest level of chemical pollutant removal and a longer filter life.
Ongoing costs due to frequent filter replacement needs. The largest filters of any residential air purifier and a 5-year lifespan on main filters results in the highest level of efficiency and long-term ongoing costs savings.
Problems accessing spare parts or new filters due to importer disruption over years to come. Australian-made filters and spare parts that are stocked locally, providing easy maintenance and support.
Filters made from cardboard, plastic or polystyrene foam. 100% steel filter casings resulting in no air leaks and chemical-free materials.
Difficulty changing filters. Intuitive stainless steel latches offer quick filter access, providing hassle-free filter changes.
Unserviceable designs = disposable air purifiers. Steel construction designed to last a lifetime. With fully serviceable designs, INOVA offers a lasting, lower long-term cost and environmentally-friendly investment.
Challenges with short motor lives, struggles to cycle air and an increased likelihood of burnout with forward-curved fans. German-engineered fans designed for 50,000+ hours of continuous operation, delivering high airflow for the long term.