Indoor Air Quality at HRHS

Hutchinson Regional Health System has several protective measures designed into our facilities’ building systems that improve indoor air quality and help protect patients, visitors, and staff. When compared to a school or office buildings, health care buildings generally have a higher design standard as it relates to ventilation and filtration.

Air Filtration

All of the air in the heating, ventilation, and air conditioning (HVAC) systems in the facilities use MERV-14 filters or better. MERV-14 filters remove more particulates from the air than the filters in most homes and other businesses. MERV-14 will remove 90% of the particulates in the air ranging in size from one to three microns.

The surgery department and other certain areas of the hospital have HEPA filters in their air handlers to remove particulates. These filters remove 99.97% of the particles whose diameter is equal to 0.3 microns or larger. This is near to the size of Covid-19 particles. HEPA filters are very effective at collecting smaller and larger particles as well.

The graph above shows the effectiveness of air filters at removing different particle sizes. Filters are measured based on their effectiveness at filtering out the most difficult size of particle to remove.

Air Exchanges

HRMC maintains a high level of air exchanges in its spaces. Many businesses and schools completely exchange the air in each room one to three times per hour. HRMC exchanges the air in its indoor spaces six to twenty times per hour. This means the air in any given room will be filter and mixed with outdoor air a minimum of six to twenty times in one hour. The same air is not being kept in the room for long and it is getting filtered more frequently. Spaces like the operating rooms will have the air filtered and exchanged or refreshed much more often.

The image above shows airflow in an operating room as it is supplied from above and returned on the sides of the room at the return grills low on the wall.

Germicidal Ultraviolet Light Treatment

HRMC utilizes ultraviolet lights to disinfect rooms and to purify air. Mobile UV lights are placed in care areas to disinfect them. Ultraviolet lights are also used in several air handling units to purify air before it is sent to rooms. Ultraviolet light is effective at killing bacteria and using it in these two ways is a safeguard for patients and staff.

The image above shows ultraviolet technology like that contained in several air handling units at HRMC.

Positive and Negatively Pressurized Rooms

HRMC has several rooms that are positively or negatively pressurized. These rooms are designed in a way to keep airborne infectious particles contained and to keep contaminants out of areas they should not be (like the operating rooms). These specially pressurized rooms serve several different purposes and areas, but they are all designed to keep patients and staff safer.

Takeaways

Staff, patients, and visitors all benefit from this technology. HRHS is ahead of most other industries when it comes to creating and maintaining a high level of indoor air quality. Other new technology like UV disinfection also benefits these groups. High air exchange rates mean that air is the freshest it can be indoors and that pollutants and contaminants are removed from the air as frequently as possible.