Hospitals pose the ultimate challenge for building management systems (BMS) designers. They have multiple environments, many of which vary considerably in air quality requirements. There are operating rooms, treatment rooms, laboratories, sterile processing rooms, imaging rooms, supply rooms, and patient rooms. With COVID, there has been a heightened concern for infectious diseases, which poses more issues.
In addition, hospitals deal with the lives of their patients every day. Nothing could be more critical.
What’s inside this blog post:
- The terminology of hospitals and BMS.
- Two of the most important areas in a hospital.
- The role of regulatory agencies regarding hospitals.
- What if there is a failure in the HVAC system?
- Other hospital systems controlled by BMS.
- FICO can help.
The terminology of hospitals and BMS
There are several unique features to the HVAC system of a hospital, and BMS plays a big part in it.
Positive pressure rooms
Most rooms in a hospital are positive pressure, designed to propel contaminants and pathogens out of rooms. Air is introduced at the ceiling level or high up on the wall, pushed downward, circulated through the room, and then exhausted at the lower levels, through doors and vents that lead the air out of the building or introduced back into the fresh air system. As the air moves through the room, it moves airborne particulates and contaminants along with it. Because new air constantly pushes the older air out of the room, it is a positive pressure room.
As with hospitals, almost all business and office buildings are positive pressure environments.
Air Changes
One measure of a positive pressure room is how many times per hour it takes to replace the entire volume of air, known as an air change. General spaces such as reception and waiting rooms, offices, hallways, and cafeterias require two to four air changes per hour. A surgical suite is far more critical, requiring a minimum of 20 air changes per hour, although many hospitals maintain their operating rooms at 25 to 30 air changes per hour.
HEPA filters
In more critical areas, such as operating rooms, laboratories, and other treatment rooms, air is introduced into the room only after passing through a HEPA filter. HEPA is an acronym for high-efficiency particulate air. A HEPA filter contains pleated material designed to remove pollen, dirt, dust, pollen, viruses, and aerosol at microscopic levels, about 0.3 micrometers. As a comparison, the end of a strand of human hair is about 60-100 micrometers. A particle of cigarette smoke is between .5 and 2 microns.
HEPA filters can capture bacteria particles such as bacteroidia, clostridia, and bacilli.
One of the challenges of a HEPA filter is that it takes more energy to push the air through the filter, so the air pressure in the ventilation system leading to those rooms needs to be increased.
Hospital facilities staff must change HEPA filters regularly, depending on the area they protect. Maintaining a record is essential, documenting whenever a filter is changed.
Negative pressure rooms
In the case of infectious diseases, the efforts around air pressure work in reverse. Hospitals don’t want those contagious, airborne pathogens to get out and infect other patients or staff. A vent or vents high on the wall or ceiling pull air out, often through a HEPA, creating negative pressure. That air is exhausted outside. When doors or curtains open in a negative pressure room, outside air is sucked in. Incoming air keeps pathogens from exiting the room and infecting other people.
Processes involving friction or movement cause particulation. During the COVID-19 pandemic, many patients underwent intubation or extubation (breathing tubes were either inserted or taken out), generating aerosol or airborne particles that can infect other patients. Many hospitals scrambled to convert positive pressure rooms into negative pressure rooms.
Outside factors and seasonal changes affect HVAC
Regional climate conditions and seasonal changes pose challenges to HVAC, too. Facilities personnel must adjust the HVAC in light of these factors. Natural events in a region are also factors, such as excessive smoke from wildfires, particulates kicked up by windstorms, and other conditions.
Two of the most important areas in a hospital
Every corner of a hospital is vital, but the operating rooms and patient rooms are two areas of special concern.
Operating rooms
- Air changes–ASHRAE (formerly known as the American Society of Heating, Refrigerating, and Air-Conditioning Engineers) sets hospital standards. ASHRAE standards call for operating rooms to have positive pressure and at least 20 air changes per hour. The air is introduced high on the wall or ceiling and directed downward at an average discharge velocity of 25 to 36 feet per minute.
- Humidity–ASHRAE standards for humidity in the operating room are 20% to 60%. Humidity is critical for patients and the professionals working in the operating room. Too much humidity interferes with the body’s ability to perspire, making the room feel warmer than it is. Excessive humidity also leads to mold and mildew growth. Low humidity causes dry skin and discomfort and is related to increases in healthcare infections.
- Temperature–ASHRAE standards for room temperature in an operating room range from 68 to 75 degrees, though personnel typically set it to 65 degrees. Like humidity, this is for patient comfort and the comfort of the operating room personnel.
Patient rooms
Insurance companies often adjust hospital reimbursements based on patient satisfaction scores. For over ten years, Medicare has based 30% of their hospital reimbursement payments on these surveys, according to an online article Breaking Down Patient Satisfaction on the USCPrice website.
Hospitals need positive patient reviews, so keeping patient rooms at a comfortable temperature is essential. Humidity levels are also crucial because proper humidity promotes healing.
The role of regulatory agencies regarding hospitals
While ASHRAE is the principal body for establishing hospital guidelines for HVAC, ASHRAE cannot enforce those recommendations. That is the duty of The Joint Commission, a non-profit international body dedicated to promoting top care and conditions in hospitals. The Joint Commission issues accreditations to hospitals at all levels. Their inspections are public records and cited in everything from hospital marketing and promotion to legal actions. When reports from The Joint Commission are good, they are a significant bragging point. When they are less than good, corrective action is immediate.
The Joint Commission addresses testing of the HVAC system and all hospital systems, often called test and balance requirements. While The Joint Commission does not set testing intervals, testing at hospitals should be regular, carefully documented, and readily accessible for review.
The Joint Commission plays such a large part in hospital accreditations that an entire industry of firms specializes in helping prepare for inspections. These firms advise hospitals on policies and will even conduct mock inspections.
Anything involving the Joint Commission is taken very seriously by hospital administrators.
What if there is a failure within the HVAC system?
Hospitals must have procedures in place if an HVAC system shutdown occurs. For example, if an electrical problem affects the HVAC serving an operating room, does the hospital have a closed system that isolates the problem so that other operating rooms are unaffected? Do facilities staff need to shut down related systems to prevent damage or contamination of other hospital areas?
There has to be a notification system in place so that other departments know about the shutdown and the particulars. In the event of a shutdown of an operating room, emergency room physicians and other personnel must be aware. This information affects how they decide to treat a patient. If paramedics or other field personnel advise that an incoming patient requires emergency surgery and the nearest hospital has HVAC problems that have shut down or limited the availability of operating rooms, the ER might direct that patient to another hospital.
Other hospital systems controlled by BMS
As it does in other applications, BMS controls other systems beyond HVAC. The electrical grid within a hospital and the allocation of electricity are essential to smooth operation and are also carefully scrutinized by The Joint Commission. In the event of a power failure, there needs to be redundant systems to ensure patients are protected and not placed in jeopardy.
Other systems typically addressed by BMS are also vital to hospitals. These include fire alarm and suppression systems, security, access control, boiler and steam lines, piped gases, vacuum lines, and other building systems. It’s not untypical for hospitals to have several buildings on campus and to have satellite facilities. This calls for mobile technology and cloud computing capabilities, all ingredients of an expertly installed and designed building management system.
FICO brings expertise to hospitals
“Hospitals are some of the most complicated BMS projects,” says Mitch Andrus, an account executive at FICO. “These types of projects involve a great deal of planning and the early involvement of all stakeholders–the facility manager, C-suite executives, department heads, and consultants. Every step is critical.”
