Five Questions to Ask Before Buying a Mobile Air Purifier for Your Business or School.

There are lots of reasons to have an air purifier operating in your business or school. Minimizing the spread of airborne viruses such as COVID-19 is just the start. You may be breathing in a variety of toxins from seasonal brush fires, factory chemicals, and vehicle exhaust, not to mention allergens. The big problem is that it’s very easy to choose the wrong air purifier. By wrong, we mean one that is underpowered for your room size, uses an inadequate method of filtration, or uses a method that generates unhealthy air.

Here are five essential questions you should ask when selecting an air purifier for your indoor space.

Is the air purifier powerful enough for my room size?

A small appliance designed for a bedroom or other small space won’t do the job in most commercial settings. In a business or classroom, room sizes and ceiling heights are generally much greater than in-home, so you need a powerful device capable of the task. Look at the specifications of the unit for the number of air changes per hour and what room size that rating is based on. Industry trade association ASHRAE recommends a minimum of six air changes per hour. (Be sure to look for this specification.) The other option is the installation of a filtration system that is built into the building HVAC system. These systems add components such as higher efficiency filters, UV-C disinfection and filters that remove organic gases from outside air pollution and inside gases from cooking and cleaning. These are designed for the systems in place, requiring an air quality professional. The upside is that such engineered systems eliminate the need for multiple mobile units, and they treat 100% of all the building air.

What method of cleansing the air is used?

An air purifier should be more than a couple of particle filters in a box, even if one is a HEPA filter. An effective system will have multiple stages of filtration, including particulate, activated charcoal, and a chemical-media filter.  A UV-C lamp may be included to kill pathogens that might accumulate on a filter. Note that a UV lamp without a chemical-media filter will be ineffective and will generate byproducts of the organic gases that are worse. Also, avoid devices that use electrostatic precipitators that generate ozone while attracting airborne particles. Be very suspect of the ability of a physically small device to purify the air in a large space.

What is the cost of operation?

Some air purifiers use custom filters, available only from the device manufacturer. This limits your ability to shop for the best prices on replacements. If the purifier uses HEPA filters, even if a standard size, they can be 10 times the cost of a high MERV (minimum efficiency reporting value) filter. While it is true that HEPA filters can capture virus-size particles, it’s a costly solution to maintain. Instead, a well-designed multi-stage air purifier will combine several technologies to filter and kill pathogens, while using much more cost-effective rated filters.

How loud is the fan at the speed necessary to clean the air?

The lower the dB rating the better. If you don’t know this number specified by the manufacturer, request it. If you find that it’s necessary to slow down the fan to avoid too much noise, you also reduce the effectiveness of the air filtration.

What is the business and experience of the manufacturer?

When COVID-19 became an overnight crisis, many companies with no experience in air filtration started selling air purifiers. Stay with companies, like ProMark Associates, who have many years of experience in providing clean air solutions. Otherwise, you may find that the units you buy are more problems than solutions, and don’t purify the air as intended.