How Many Air Purifiers Do I Need In My Office?

So, you’ve decided to implement air purification in your offices. That’s great, but now the fun really begins! Despite the research you’ve done, some of the questions you might still be asking yourself are: 

  • What size air purifier do I need? 
  • How many do I need? 
  • Where should I put it in my office? 

Odds are, you’re feeling a little overwhelmed by all the options available. In this blog, we’ll try and answer all these questions and more. 

The first and most important factor to consider is the size of your office. The capacity of an air purifier is measured by something called Clean Air Delivery Rate (CADR). Essentially, it’s a measure of how many m3 of air that an air purifier is capable of cleaning each hour. 

Sounds simple right? All you have to do is measure the m3 of your office space (length x width x height) to find an air purifier with a matching capacity? 

Unfortunately it’s not that simple…. 

For an air purifier to be properly effective, it should be filtering the air in your office multiple times per hour. The recommended guideline for commercial or residential use is once every 12-15 minutes, or 4-5 times per hour. On Amazon, you often see manufacturers making extravagant claims about the size of the rooms their air purifiers are effective in – but if you check the technical specifications, very often the machines are only capable of filtering the air in a room that size around 2 times per hour, which is half the recommended amount of times! 

So to determine the air purifier that’s best suited for you, you need to calculate the m3 of your office, but then multiply that by 4.5 to calculate the CADR you require. And typically for smaller offices, or conference rooms – anything up to around 60m2, with a standard ceiling height – you should be able to take this figure and there will be multiple options on the market capable of delivering what you need – our Zona 620 is a very popular option here. 

However, if you’re in a larger shared office space then you are going to struggle to find a single ‘plug and play’ portable air purifier with a CADR higher than 650m3/hour with the appropriate level of filtration. But don’t panic – there are still multiple solutions out there. 

The first option, which is likely to be the simplest and most cost-effective for many, is to install more than one air purifier. You can add together the CADR for each machine until you achieve the required figure. 

As an example, let’s say you’re in an office with that’s 24m long and 9m wide. You have normal ceilings, at 2.4m high. Your total CADR requirement is 24 x 9 x 2.4 x 4.5 = 2332m3. In this instance we’d recommend 4nr Zona 620s. With a CADR of 620m3 each, the combined CADR that 4nr will be able to achieve is 2480m3 – more than sufficient for your needs. 

There are other options for you. Our free-standing Zona Health Air Purifiers have a CADR rating of 1160m3/hr, so if you are looking for a more fixed option, then this might be the one. 

Alternatively, a lot of our clients love the Zona CM ceiling mount air purifier. Unobtrusive and without any of the ducting requirements of a HVAC system, these are capable of delivering 1000m3 pure air each per hour and can be integrated to your Building Management System for ease of operation. 

There is one more key point to be made, and while it can seem obvious, it is often overlooked. For your Air Purifiers to be fully effective, they must be located as centrally as possible. If you leave them up against the wall, or tucked in a corner, then the fans they use to draw air in to be filtered are going to be partially blocked, negatively impacting the CADR your purifier can achieve. 

Likewise, if you have more than one air purifier in your office, these need to be split up and located equidistant from each other. If you have them all in the same area, then yes that part of your office is going to have great air quality, but the other side of the room – not so good! 

For more information on the air purifier that’s most suited to your needs, you can check out What Air Purifier do I need (, or we offer a free assessment for any commercial building. Simply send a copy of your floor plan through to, or give us a call to find out more!  

Comments are closed here.