A Safer Workplace Series with Hollander Design Group – Air Quality
by Jeffrey Hollander, Founder/President of Hollander Design Group, & Viveca Bissonnette, Founder/Principal of Hollander Design Group
In our previous articles we have addressed the need for building trust and establishing strong communication channels to ensure the transition back to the office is smooth and safe. We have not really asked the question yet why we are going back to the office. In talking to our clients and friends, there seem to be several drivers: need for social stimulation, continued learning and innovation. These are all group activities. If we accept that all forms of meeting will be a driving factor in why people travel to the office, then we must figure out how teams can work in close proximity.
Each issue that could potentially impact our health when we enter a building must be examined from two views – what can we do now, and what long-term investments will protect us moving into the future? The nature of the COVID-19 virus directs our attention to air quality. First, we’ll respond to the question, “What can we do to immediately begin improving our air quality?” Then, “What are the long-term changes we should be making for both existing and new buildings?”
Air and mechanical systems play a large role in creating safe work environments. Since the 1970s, building codes have focused on reducing energy usage and minimum fresh air quantities. As such building designs are incentivized to reduce the air flow that keeps us healthy. Did you ever wonder why meeting rooms get stuffy? Reduced air flow and reduced fresh air in favor of energy savings.
The technology behind energy savings is a great benefit, but have we gone a little too far in that direction, at the expense of our wellbeing? LEED and WELL have both pushed back on energy savings efforts, prioritizing human health instead.
Perhaps it is time to re-think some of these energy saving practices in favor of more health promoting practices.
Healthcare environments, where minimizing infections is critical, require air change rates that are often double those required for office space. In operating rooms and high-tech clean rooms where limiting contamination is critical, high levels of filtration and careful engineering of the air flow ensures that patients and processes are washed with sterile air. For minimal extra cost, we can borrow some good practices from these critical environments to improve the health of the spaces we inhabit.
If we’re doubling the fresh air in a healthcare environment where sick patients are common, isn’t it reasonable to also do that in the workplace – a place we spend so much of our time each week? We accept bad, unhealthy air in our workplaces – by why do we accept it?
Right now, we need more fresh air inside our workspaces, and few of us have the ability to open windows. There is good news for those of us living in a temperate climate, where most of the installed equipment was required by the energy codes to include economizer capabilities that pull comfortable outside air into the system. Doing this will sacrifice some energy efficiency and may cause interior temperature to fluctuate by a few degrees, but this is a point in time where exceptions might be appropriate.
General Recommendations for Immediate Changes
>Adjust building management systems (BMS) to open economizers. Most systems have excess capacity.
Right now, we need more air filtration for recirculated air in our workspaces. Like N95 masks, filters trap viruses being carried on water and dust particles. The good news is that it can be relatively simple to change out the filters in your existing systems with better ones.
>MERV 14-15 filters are roughly equivalent to N95 masks.
>Current codes in California and other states already require MERV 13 filters, but many older systems have lower filtration levels. Upgrade existing filters with a higher MERV value.
>Adjust fan motors and speeds to compensate for the pressure loss through dense filter material.
There are likely trust issues working within confined spaces, even with a reduced number of occupants, but meeting spaces are critical to the way we work. We can provide some simple solutions to allow for the safe return of the removed seats. Because most conference rooms already have dedicated air conditioning zones, we can sterilize the air fairly simply.
>Provide wall mounted UV lights placed near the return air grilles to sterilize the return air before it gets recirculated.
>Increase filtration and the fan speed at the local fan coil or terminal unit for improved air changes and cleaning.
Right now, fresh air in restrooms is critical. Even before the COVID-19 pandemic, smelly restrooms were the source of frequent complaints.
>Run the exhaust fan full time while the building is occupied. Restrooms are typically stacked and served by a single exhaust fan on the roof.
>Increase fan speed and exhaust volume.
>Prop entry doors open, assuming that line of sight is not an issue.
Helping office workers feel safe will require both cultural adjustments and construction upgrades.
We’ve looked at solutions to tweak existing air delivery systems to make them as safe as possible with simple adjustments or upgrades.
But, the design of air delivery systems will need to change for the long term. The remaining discussion here assumes some amount of construction that would typically be included in a refresh or complete build-out of space as leases expire or as companies determine that additional steps are desirable. Our firm intends to include these as “good design” going forward. The costs are projected to be nominally more than typical construction costs. We anticipate that codes will evolve and catch up over time to include many of these items.
Recommendations for New Buildings
New buildings should be designed taking cues from the design of healthcare environments, increasing the number of air changes per hour will make the workspace healthier. Voluntarily increasing the volume of air that is being delivered to each space beyond the minimums required by code will remove more contaminants from the air, including dust and vapor particles that carry viruses.
>Increase air changes from 6-8/hour (typical) to 10-12/hour (suggested).
>Increase the percentage of fresh air from 15% to 30%.
>Provide additional air handlers to allow for additional zones within a building. Segregate work zones and amenity zones to prevent cross-contamination between zones.
>Provide additional filtration and/or UV light sterilization.
>Consider ducted return air in lieu of plenum return air. Segregate return air zones to prevent cross contamination.
Open Work Areas zoning and distribution of air within zones should be re-considered.
>Segregate large open areas with multiple zones. Segregate plenum return to limit cross contamination.
>Deliver the air more strategically to bathe occupants in filtered or sterile air at the center of the space and carefully remove contaminated air from corners and perimeter.
Enclosed Meeting Rooms require special consideration, as the density of occupants is the highest in these spaces. As we stated previously, meeting rooms will become more important as remote work and part-time remote work increases. These will be the spaces that remote workers visit when they do travel to the office. Again, we can take some cues from clean rooms and operating rooms to make these spaces safe.
>Separate meeting areas into discrete zones to prevent cross contamination.
>Design a minimum of 12-14 air changes per hour.
>Deliver the air over meeting tables where people are gathered. Return contaminated air from corners, near the floor.
>Duct the return air for each room and provide additional filtration and UV light sterilization within the return ductwork.
>Commission each room to confirm performance.
Recommendations for Existing Buildings
Existing buildings are a bit more difficult. Increasing air changes and fresh air volumes in existing buildings will be limited by the size of existing vertical shafts. In order to increase air changes delivered within a space:
>Increase fan power and filtration to MERV 14 for rooftop air handlers.
>Convert existing supply air shafts to tempered fresh air using existing air handlers.
>Provide additional cooling at each floor/zone. Consider a chilled beam system.
>Extend the return air plenum in order to install UV light sterilization. Provide access to service lighting on a regular basis.
There is no guide – no game plan – when you’re out ahead of the curve. We’re listening to medical professionals and the scientific community, and taking cues from other industries – most importantly, healthcare. Improving our health is the goal here. And it’s impractical to turn every office into a medical-grade air quality space. But, modifying our workspaces to lean more in the direction of human-healthy spaces is achievable. Most of the recommendations are common sense steps that balance the line of what’s practical – things we can all do within the limits of budget and time.
Special thanks to our partners at CGK Consulting Group, Inc. for helping us imagine new solutions. We can do this together.