IAQ in Hospitals: CDC Guidelines Part 2
As discussed in my last post, indoor air quality (IAQ) is of critical concern in hospitals and other medical facilities where airborne contaminants are particularly hazardous to both patients and medical workers. A recent report published by the Center for Disease Control (CDC) issues guidelines for minimizing healthcare-associated infections that include ventilation standards and other HVAC-related best practices.
In my earlier post, I highlighted some of the recommendations given for day-to-day ventilation and other HVAC functioning. But when it comes to remediation projects within a functioning facility, the precautionary practices essential in maintaining a healthy environment are particularly critical.
With this in mind, here are some highlighted recommendations outlined in the CDC report that directly relate to best practices for ensuring proper IAQ during remediation projects in a hospital or other medical facility.
- Before the project gets under way, perform an ICRA to define the scope of the activity and the need for barrier measures.
- Determine if the facility can operate temporarily on recirculated air; if feasible, seal off adjacent air intakes. If this is not possible or practical, check the low-efficiency (roughing) filter banks frequently and replace as needed to avoid buildup of particulates.
- Seal windows and reduce wherever possible other sources of outside air intrusion (e.g., open doors in stairwells and corridors), especially in PE areas.
- Seal off and block return air vents if rigid barriers are used for containment.
- Ensure proper operation of the air-handling system in the affected area after erection of barriers and before the room or area is set to negative pressure.
- Create and maintain negative air pressure in work zones adjacent to patient-care areas and ensure that required engineering controls are maintained.
- Provide construction crews with 1) designated entrances, corridors, and elevators wherever practical; 2) essential services (e.g., toilet facilities) and convenience services (e.g., vending machines); 3) protective clothing (e.g., coveralls, footgear, and headgear) for travel to patient-care areas; and 4) a space or anteroom for changing clothing and storing equipment.
- In patient-care areas, for major repairs that include removal of ceiling tiles and disruption of the space above the false ceiling, use plastic sheets or prefabricated plastic units to contain dust; use a negative pressure system within this enclosure to remove dust; and either pass air through an industrial-grade, portable HEPA filter capable of filtration rates of 300--800 ft3/min., or exhaust air directly to the outside.
- Commission the HVAC system for newly constructed health-care facilities and renovated spaces before occupancy and use, with emphasis on ensuring proper ventilation for operating rooms, AII rooms, and PE areas.
Some highlighted recommendations for ventilating protective environment (PE) rooms.
- Incorporate ventilation engineering specifications and dust-controlling processes into the planning and construction of new PE units.
- Install central or point-of-use HEPA filters for supply (incoming) air.
- Ensure that rooms are well-sealed by 1) properly constructing windows, doors, and intake and exhaust ports; 2) maintaining ceilings that are smooth and free of fissures, open joints, and crevices; 3) sealing walls above and below the ceiling; and 4) monitoring for leakage and making any necessary repairs.
- Ventilate the room to maintain >12 ACH.
- Locate air supply and exhaust grilles so that clean, filtered air enters from one side of the room, flows across the patient's bed, and exits from the opposite side of the room.
- Maintain positive room air pressure (>2.5 Pa [0.01-inch water gauge]) in relation to the corridor.
- Maintain airflow patterns and monitor these on a daily basis by using permanently installed visual means of detecting airflow in new or renovated construction, or by using other visual methods (e.g., flutter strips or smoke tubes) in existing PE units. Document the monitoring results.
- Install self-closing devices on all room exit doors in PE rooms.
- Do not use laminar air flow systems in newly constructed PE rooms.
- Ensure that the patient's room is designed to maintain positive pressure.
- Use an anteroom to ensure appropriate air-balance relationships and provide independent exhaust of contaminated air to the outside, or place a HEPA filter in the exhaust duct if the return air must be recirculated .
If you or your company are serious about branching out to offer HVAC services for the medical industry, understanding best practices for working in this unique environment is critical. A quick search will reveal a variety of organizations that help provide training and other resources needed to educate you and your staff about the fundamentals.
This blog was developed by Aeroseal. All posts, sponsored and un-sponsored have been reviewed and approved by the Sustainable Community Media Editorial Team to ensure quality, relevance/usefulness and objectivity.