COVID-19 is a highly contagious virus that is predominantly spread through contact and dispersion of droplets between people and nearby surfaces. Because the elderly are among the most vulnerable to COVID-19, there are some measures long-term care facilities (LTC) can take to help prevent the spread of the virus. Effective measures for LTC facilities include modifications to HVAC systems, cleaning, screening occupants, staff and visitors and containment.
Isolation Wings
In a long-term care facility, one of the most effective ways an HVAC system can be used to help stop the spread of a virus is to keep it contained to a specific area and utilize pressure zones. If residents within the facility become infected with a virus, moving them away from others who are not infected as quickly as possible will help reduce the spread of the virus. In order to accomplish this goal, LTC facilities should identify areas in their communities that can be changed into isolation wings. The drawing below illustrates how a typical resident wing could be converted to an isolation wing.
Isolation wings are developed by turning blocks of resident rooms into Airborne Infection Isolation (AII) rooms. In most LTC facilities there are not many true AII rooms; however, the current COVID-19 pandemic has prompted many LTC facilities to develop plans to either quickly turn a block of rooms or an entire wing into an AII area. AII rooms are utilized in healthcare and long-term care facilities to help keep airborne pathogenic organisms from spreading throughout the facility and infecting others. The drawing below illustrates how a typical resident room could be converted to an isolation room.
The 2018 FGI Guidelines for Design and Construction of Residential Health, Care, and Support Facilities provides requirements for the construction of an AII room including requiring 2 air changes per hour (ACH) of outside air and 12 ACH total. The elevated air changes are implemented to capture and contain contaminants with proper filtration.
Anterooms for AII rooms, while not required by the 2018 FGI Guidelines, provide multiple advantages. First, they provide an airlock chamber that can be used to help maintain pressure control between the corridor and the resident room. Second, they provide a location for the healthcare worker to don personal protective equipment (PPE) prior to entering the room as well as remove the PPE when leaving.
Some important considerations for identifying potential AII spaces include:
- Identify an area of the facility whose HVAC system is either already separate or can be easily segregated from other areas.
- Evaluate the system(s) that could be utilized to provide outside air in sufficient amounts to address the planned operations. Central and/or local systems that supply outside air will need to be reviewed to verify their ability to accommodate increased outside air during peak cooling and heating seasons.
- Dedicated outside air systems (DOAS) may need to be rebalanced to distribute air in sufficient quantities to all spaces. A review of occupants and usage may be performed to verify minimum outside air quantities and how air may be shifted around the system to areas that require additional amounts of outside air for the new or temporary operations planned. Note, DOAS systems that serve multiple spaces, including new temporary AII rooms, may continue to remain in operation without the need to separate the systems. However, to maintain pressurization and reduce potential for cross contamination, the system must operate 24/7. Positive airflow through the duct system will prevent possible cross contamination through the duct system.
- Balancing will need to be adjusted to make the resident rooms negative to the corridor or anteroom if one exists or is provided as a temporary measure.
- If recirculating HVAC systems, such as fan coil units or water source heat pumps, are being used within the AII room to provide heating and cooling to the space and these are the sole source of outside air to the room, they will likely be required to operate continuously. In this scenario, the exhaust from the room will likely need to be increased to make the room negative with respect to the corridor. In systems where the exhaust fan airflow cannot be increased by balancing, a separate exhaust system will need to be investigated.
- Equipping the isolation wing with provisions for medical-gases will provide future flexibility to treat residents who become infected with a contagious disease. Providing medical-gas connections in the resident rooms as well as a location outside for bulk oxygen tanks to quickly connect to will make switching an area into an AII area quicker and easier. As an immediate solution, local gas cylinders may be utilized, but code compliance for stored oxidizing material quantities must be verified. In some cases it may be necessary to locate cylinders outside. To comply with code requirements, stored oxygen cylinders should be located within ventilated enclosures.
Isolation spaces, whether rooms or wings, are one strategy to help reduce the spread of the virus that must be implemented as part of a multi-pronged approach to help long-term care facilities maintain safer environments and productive operations.
