Accreditation & Regulatory Journal
April 2023


Ventilation Requirements for Hospitals

By: William (Billy) Kinch
Ventilation in healthcare facilities can sometimes be a little tricky. Especially when trying to understand how they are applied from a regulatory standpoint. I am going to do my best to try and help you understand some of the more confusing areas.
The first thing we should look at is where you find the standards that healthcare facilities use when it comes to heating, ventilation, and air conditioning (HVAC). On July 5, 2016, the Center for Medicare/Medicaid Services (CMS) officially adopted the National Fire Protection Agency (NFPA) code for Healthcare Facilities (99-2012 edition). It adopted this code AND all its references. When you look at NFPA 99-2012, you will find chapter 9 – HVAC. It is there that you will find the requirement for organization HVAC systems meeting the ASHRAE 170 Ventilation of Healthcare Facilities. As you go back to Chapter 2 (Referenced Publications) of NFPA 99 you will find ASHRAE 170 2008 edition as being the referenced standard. This is the document that healthcare facilities will use to be in compliance with CMS regulations.
This article is not going to cover every possible ventilation requirement for healthcare facilities. That would be a lot longer conversation than we have time for right now. I want to focus on some areas that generally come up during an Accreditation Survey at hospitals.
Operating Rooms
ASHRAE 170-2008 has a Table 7.1 Design Parameters; this table is where healthcare facilities will find the requirements around things such as temperature/humidity, pressure relationships, minimum air changes, etc. For operating rooms, it states that the temperature is to be between 68-75 degrees. There is a statement that does permit surgeons or surgical procedures to exceed the minimum ranges. Most, if not all, regulatory agencies would require facilities to have some documentation when the ranges are exceeded (both below and above). When it comes to humidity it can be a little confusing. CMS states that humidity levels are to be between 35%-60% in operating rooms. However, they did release a categorical waiver that would permit operating rooms to meet the range set forth in ASHRAE 170-2008 which allows a range of 20%-60%. Facilities are allowed to use the 20%-60% range provided they declare the waiver at the beginning of a survey, and they conduct a risk assessment to ensure that the manufacture instructions for use (IFUs) permit their equipment to be used/stored in an environment with a 20%-60% range.
Sterile Storage
The most frequent citation in sterile storage areas is around the temperature range. ASHRAE 170 states that the temperature for sterile storage areas is to be between 72-78 degrees F. The humidity level is set at a max of 60%.
Decontamination rooms are where a lot of discussion is started. ASHRAE 170-2008 states that the temperature for decontamination rooms is to be between 72-78 degrees F. This can seem a little high when it comes to the staff that are working in these areas. These ranges were set up from an infection control standpoint. ANSI/AAMI ST-79 states that lowering the temperature does not do anything for the staff since there is not enough exposure to the skin. Therefore, alternative means should be in place to keep staff cool. Airborne Infection Isolation (AII) Rooms
Most organizations meet the requirements when it comes to AII rooms. However, there is one specific thing that you may not be aware of. ASHRAE 170-2008 states that AII rooms should remain under negative pressure relative to all adjoining rooms whenever an infectious patient is present. The rooms should be tested for negative pressure daily whenever an infectious patient is present. Many organizations have a system in place to monitor the pressure of the AII rooms to ensure they are negative, when needed. An alarm will sound anytime that the room pressure falls out of range. So, most organizations rely on this system for their compliance. CMS has an infection control audit tool that takes this just a little bit further. It states that when AII rooms are in use for a patient on Airborne Precautions, air pressure is monitored daily with visual indicators (e.g., smoke tubes, flutter strips), regardless of the presence of differential pressure sensing devices (e.g., manometer).
Evaluate your HVAC systems to the ASHRAE 170-2008 standards to ensure compliance. Additionally, use your state regulations as guidance as well. Most states do reference ASHRAE 170 but may have different editions. Don’t get caught unprepared.