Air Purifiers Buying Guide – What to Consider When Buying an Air...

Air Purifiers Buying Guide – What to Consider When Buying an Air Purifier


Air purifiers refer to equipments or devices used to remove impurities and contaminants from air. They are popularly marketed as being very beneficial to asthmatic and allergic people, other than ensuring the air is clean and fresh.

They could be stand-alone devices (for smaller residential places) or working together with HVAC (heating, ventilation and air conditioning) or AHU (air handle unit) systems in the case of larger institutions such as industries, commercial centers and hospitals.

Choosing the right air purifier can be a daunting task since there are many air purifiers that have been highly hyped through powerful advertisements and promotion.  However, if you want to buy both an efficient and highly usable air purifier for commercial or residential use, here are some of the very important factors, to consider:

Effectiveness of Air Purifiers

The first and most important factor you should consider when buying an air purifier is its effectiveness. This includes both the particle size of impurities a certain brand is able to remove as well as its efficiency i.e. you need to look at the various particle sizes that a certain air purifier can remove and to what percentage.

While making a decision on this, you need also to consider the nature of contaminants you are trying to get rid of. Viruses, tobacco smoke particles and bacteria in the air might need a different type of purifier as opposed to larger particles.  Some of the common air impurities that should be removed include fungi, molds, tobacco smoke, pet allergen, pollen, dust mites allergen, bacteria, etc.

Generally, the HEPA air purifiers are considered the most effective in getting rid of allergens in the air as they can remove up to 99.97% of as small as 0.3 microns particles. Negative ion and ozone generators can purify up to 0.01 microns of particles from air while Oasis air purifiers are known to remove up to 0.001 microns, meaning they will get rid of almost anything from air including viruses, herbicides and pesticides.

Noise Levels of Air Purifiers

Noise level is yet another very important consideration to bear in mind when buying air purifiers. Most of the HEPA, carbon based and electrostatic purifiers use motors in drawing more air since it is only the air that passes through their filters will be cleaned. Such purifiers are much nosier compared to the ozone generators and negative ion which utilizes fans to distribute negative ions and oxidizers instead of sucking all the air into their purifying unit. Even if an air purifier uses a fan, you still need to know if the fan is powerful and very noise or not.  Generally, large air purifying units will be nosier that smaller units since they have to purify larger volumes of air.

Electricity Consumption Air Purifiers

The amount of electricity consumed by an air purifier is very important since it will have an impact on the overall operation costs. Although some air purifiers might appear expensive when buying them, it will advisable to go for such purifiers if you realized they consume less electricity. To get a hint of the amount of electricity that a certain air purifier model or brand will use, you need to check on watts number that the manufacturers have listed. Once you have them, you can use the below equation to determining annual electricity costs:

Annual Electricity Costs = {Watts/100) x (KWH) x (Hours Operated)

If it runs for 24 hours a day, the hours operated per annum will be 365*24 = 8760. The KWH or Kilowatt Hours will be the rate that your electricity utility company charges you, which is typically $0.08 to about $0.15.

Odor Removal By Air Purifiers

When buying air purifiers, you also need to consider its ability to remove or reduce strong odors. Air purifiers that utilize ozone, oxidants and carbon are the most ideal in removing odor since they can destroy or neutralize order-causing particles while carbon will afterwards get rid of these particles. Avoid HEPA and other purifiers since they do not remove odor-causing particles. Negative ion air purifiers are the most effective in getting rid of order causing particles. However, if such a purifier also uses ozone, ensure ozone does not go high so much to an extent of making the air irritating.

Types of Filters and Replacement Costs

When buying air purifiers, you need to consider both the type of air filters used and the replacement costs of some parts, especially the filters. Some manufacturers have the wash and replace pre-filters while others require you to replace them. Typically, air purifier filters are replaced after every three months. Look at the cost of replacing filters and other parts. This will help you determine which type of air filter will be cheapest since this cost will add up to the operating costs.

Some of the common filters used in air purifiers include HEPA filters (for HEPA purifiers), granulated activated carbon, charged media filters, electrostatic filters and electronic filtration systems. Generally, electrostatic filers are less inexpensive as compared to HEPA filters. Even the process of replacing filters themselves should be considered since some require an expert while others can be done by anyone.

Chemical and Gas Removal

If you want to use your air purifiers on environments that have a lot of chemical fumes and gas, you need to consider purifiers capable of doing so. Some of the common chemicals and gases you will want to get rid of include aerosols, volatile organic compounds (such as cleaning supplies, toluene, benzene, formaldehyde, adhesives, vanishes, paints, etc). These chemicals and gases are known to cause nausea, headaches, eye, nose and throat irritation and in extreme cause nervous problems. To get rid of gases and chemicals in air, you need to go for air purifiers that use activated carbon since it has the ability to adsorb gases and chemicals that the HEPA filters might not trap.

Cost per Foot Coverage

When buying air purifiers, you need to calculate the cost per square foot cleaned. Some air purifiers might be lowly priced but when you calculate the cost per square foot air cleaned, they could be expensive at the end of the day. You can calculate the cost per square foot cleaned by dividing the air purifiers square footage coverage by its cost. You should also bear in mind electricity costs too in arriving and this figure.

Other Factors to Consider

Other than the above factors, ensure you consider the following when buying air purifiers:

  • Warrant and guarantee given
  • Portability and size of the air purifier you want to buy
  • Durability and manufacturers reputation in making air filtration and purification systems
  • The mode of operation of the purifier where you should seek to understand how exactly the specific models and brands you are considering work.
  • Cost of the system
  • The rate of air purification to know if it will support a certain application or not
  • Other maintenance costs