Commercial Building Air Filtration During COVID-19
Camfil HVAC air filtration experts, Mark Davidson and Greg Herman explain why commercial buildings facility managers need to use high-efficiency commercial filtration in public buildings after COVID-19 pandemic.
Camfil has been invited to consult on articles for major news networks following widespread air filtration mandates for publicly accessible buildings. With decades of experience in highly sensitive air filtration applications including biosafety, healthcare, and the food and beverage industry, Camfil’s knowledge and expertise is an important tool amidst the confusion surrounding the topic. But one of the downsides of media coverage is that it’s sometimes difficult to fully explain complex, scientific issues in the time allotted. To bring some clarity for facility managers and others, Camfil has released a new video explaining MERV-13 air filters, the importance of a MERV-A rating, and advice for publicly accessible facilities.
“If your system has the capacity, Camfil air filtration experts recommend an air filter labeled as a MERV-15A or MERV-16A. A basic guideline would be the highest MERV-A that your infrastructure can handle,” says Greg Herman, Camfil’s National Accounts Segment Manager.
What is the Difference Between MERV-13 and MERV-13A?
Recommendations and mandates have recently been citing MERV-13 air filters as a starting point for reducing infection risks in publicly accessible buildings. In the filtration industry, efficiency refers to ASHRAE’s (The American Society of Heating, Refrigerating and Air-Conditioning Engineers) national testing standards, known as MERV, or Minimum Efficiency Reporting Value. Some manufacturers rely on an electrostatic charge that temporarily increases the MERV value of their air filters. As this charge dissipates over time, so does the air filter’s MERV value.
More resources here: https://www.camfil.com/en-us/products/general-ventilation-filters/panel-filters
Though it may seem like a small difference, it’s essential to know the air filter’s MERV-A value. “Many states and organizations are pushing MERV-13,” says Mark Davidson, Manager of Marketing and Technical Materials at Camfil USA, “and because they are not specifying MERV-13A, effectively speaking, many are actually getting only MERV-8 filtration.”
When it comes to stopping the spread of infection, the higher the air filter efficiency, the better.
COVID-19 & Respiratory Droplets and Droplet Nuclei in Commercial & Public Buildings
Respiratory droplets and droplet nuclei are two categories of droplets based on size and are expelled when people cough, sneeze, talk or even breathe. Respiratory droplets are those greater than 5 microns in size. Masks and social distancing measures are designed to prevent us from inhaling these larger droplets from infected individuals, and sanitizing measures prevent us from picking them up off of surfaces once they settle nearby.
Droplet nuclei on the other hand are much smaller and lighter, less than 5 microns in diameter, and can linger in the air for longer periods of time. They can get caught in the return of an HVAC system and recirculate into other parts of the building, meaning that they can infect a larger group of people. This is the reason for needing high-efficiency filtration in public buildings.
Generally speaking, the higher the MERV-A rating of an air filter, the better. However, high-efficiency air filters can require more space than many air handling units are capable of holding.
What If My Commercial Building’s Air Handling Unit Has Limited Space?
“Any time you have the space, you should use at least a 6-inch or 12-inch deep air filter,” advises Herman, “but many buildings only have the physical space for a two-inch deep air filter.”
The air handling units in some buildings have limited capacity to hold air filters with greater depth because the building may have been designed with many smaller units as opposed to a few larger ones. However, some units can be reconfigured to make a wider range of air filter options available. Camfil recommends that you work with an HVAC professional who is knowledgeable in both air filters and air handling equipment.
If the consulting professional determines that the examined air handling unit can’t be configured to hold a 6-inch or 12-inch deep MERV-13A or higher air filter, other options will have to be considered.
If a local municipality has issued enforceable mandates that require MERV-13 efficiency and the only depth the air handling unit(s) will accept is 2-inches, then two paths are available.
First, there are MERV-15/14A and MERV-13/12A 2-inch air filter options available, but the operating costs are higher than preferred or anticipated. COVID-19 has increased the cost of doing business in many areas and air filtration may be no exception. Second, if faced with a MERV-13 regulatory mandate and budgetary concerns that prevent the first choice, then 2-inch MERV-13 (not MERV-13A) air filters could be sourced, but be aware that the actual performance of MERV 13 air filters will be closer to MERV-8 after a period of time.
If however, there is not an enforceable mandate but perhaps the request is to follow guidelines calling for MERV-13, then considering a MERV-9A air filter is highly recommended to achieve a higher level of overall filtration performance over a longer period of time. “A MERV-13 air filter that drops quickly to a MERV-8 and remains in service for four months does not offer higher protection than a MERV-9A that starts as a MERV-9 and remains there for as long as it’s in service,” says Herman.
“Whatever optimal air filter you choose, you should also always consider in-room air purification units, such as the CamCleaner CC500 as a supplement. If the mandate is to install MERV-13 and budget constraints force the installation of a charged air filter, Camfil strongly suggests this as a means to offset the drop off in efficiency,” says Davidson.
Work alongside a Camfil representative to find the optimal solution for your building’s needs.
About Camfil Clean Air Solutions
For more than half a century, Camfil worldwide has been helping people breathe cleaner air. As a leading manufacturer of premium clean air solutions, we provide commercial and industrial systems for air filtration and air pollution control that improve worker and equipment productivity, minimize energy use, and benefit human health and the environment. https://www.camfil.com/en-us