How is the air quality across your healthcare portfolio—and how can you be sure?
Healthcare facilities of all kinds can suffer from poor indoor air quality, just like any other building type. Some kinds of spaces, such as operating rooms, have strict regulations regarding air changes or the ability to recirculate some indoor air, but other areas are held to different standards. The differing needs of spaces and the importance of patient and staff satisfaction underscore how crucial it is to understand the factors impacting your facility’s IAQ—and to monitor them closely so you know when to take action.
Major Contributors to Indoor Air Quality
There are five key factors that affect indoor air quality: temperature, humidity, quantity of air, the presence of chemicals and other contaminants, and the quality of outdoor air brought inside. In most healthcare facilities, the HVAC system will be the way you address these considerations, explained John Swift, global lead—healthcare, science and technology for Buro Happold.
Specifically, you’ll use the HVAC system to address six concerns, according to an article by Buro Happold:
1. Air filtration. You’ll want a minimum MERV 13 rating on your filters; consider MERV 15 if you can. The higher the MERV rating your filters have, the more particles they can capture.
2. Air exchange and fresh air rates. Buro Happold recommends fresh air rates up to 30% higher than the code minimum, and/or an HVAC design that allows up to 100% outdoor air when possible.
3. Humidity control. “Humidity is a big deal when it comes to air quality,” Swift explained. Some are recommending to provide year-round humidity between 40-60%, which will require active humidification during the heating season. This is costly and can cause other problems and should be addressed on a case by case basis.
4. Pressurization. Design for maximum fresh air in occupied zones and pressurize to induce airflow clean to less clean/unoccupied spaces, according to Buro Happold’s recommendations.
5. Active air treatment. Buro Happold suggests referencing ASHRAE guidance for these systems to disinfect indoor air.
6. Air quality monitoring. There are multiple options on the market for monitoring indoor air quality. Continued tracking is key to maintaining good IAQ. “You can interpret a lot just from CO2 levels in a space,” Swift explained. Air quality monitoring can also measure VOC and particulate levels, humidity and more.
How IAQ is Handled in Healthcare
Many spaces in hospitals have specific requirements for air exchange rates—for example, operating rooms should have 25 air changes per hour, roughly four times as much as you’d have in a laboratory space, Swift said. However, high air exchange rates on their own aren’t a guarantee of better air quality.
One thing that can negatively impact air quality, especially in spaces like crowded emergency room waiting areas, is the presence of people with infectious diseases. Dilution and filtration of the air around these patients are important contributors to infection control, Swift said.
“Another thing is the way you handle food and waste,” Swift added. Hospitals generally address the waste side through having separate spaces for things like soiled linens, but wafting food smells can also make hospital stays unpleasant from an air quality perspective. “That’s an air quality issue, and it’s not necessarily easy to control. Try to have a staging area where you’re dealing with things under negative pressure so the smells aren’t disseminating across hallways and have it sealed properly until it gets delivered. That’s one that isn’t thought of enough.”
HVAC infrastructure also plays a role here—specifically, where you take the air into the building and where you discharge it. It’s critical that you’re not discharging exhaust anywhere near the area where you’re taking fresh air into the building. Outdoor intakes near loading docks or kitchen exhaust fans from adjacent buildings can also create poor IAQ inside, Swift said.
“An underappreciated component is how the air is distributed,” Swift said. “If you’re in a patient room and the supply air register is blowing on you, it can be very unpleasant. Distribute that air in a way that maintains temperature control and ventilation requirements but doesn’t make you feel like you have a draft around you.”
Red Flags for IAQ and How to Handle Them
Designing to the minimum requirements instead of operating at the optimal level sets healthcare facilities up for IAQ failure. In newer facilities, ensuring optimal IAQ is easier because they have the benefit of evidence-based design and integrated design solutions, while older facilities may have lower budgets for optimization and a backlog of deferred maintenance to deal with. A lack of IAQ monitoring can also plague older healthcare facilities “even if the space was set up to be optimized for air quality on day one,” Swift said. “Over time, you don’t know if the system has gone off spec.”
Continued testing and monitoring of the building systems will give the facilities team valuable data to see what needs to be fixed, Swift added. Often, when systems break down, they’re fixed, but not in a way that maintains optimized operation—for example, you may not even know that a damper has broken and is stuck in the closed position because there’s no air quality monitoring in the spaces affected by that damper.
“One way facilities can start making people feel more comfortable that they’re paying attention to this issue is that they can monitor the air quality in a space and say ‘Here’s our readout; everything’s on spec right now,’” Swift explained. “If for some reason, someone is saying ‘Why is that room so high in humidity? Why are the CO2 readings so high?’, that would give you an indicator that you should check the damper.”
The facilities team should be in the habit of checking filters and outside air dampers every three to six months, as well as “the human factor of noticing if the air quality feels good in a space,” Swift said. “If you smell food on the floor everywhere you go, that means there’s not enough ventilation on that floor.” Ask your facilities team to notice if the air seems stale or smells are traveling. It’s all about making sure people can breathe easy in your facility—and paying attention to indoor air quality is the path to get there.