Due to the emergence of the COVID-19 pandemic in 2020, many hospitals have been scrambling to create negative pressure isolation rooms to accommodate a large number of patients.
This article aims to provide a quick overview of the various components of negative air machines that can be used in this situation.
What Are Negative Air Machines?
A negative air machine is used to clean and maintain the air in various areas, such as factories, medical facilities, and job sites. It can also create negative or positive air pressure in areas with lead, asbestos, and mold.
Aside from keeping the air clean, negative air machines can also help create a safe environment for the patients and staff members. They can isolate a space and prevent the spread of harmful pathogens. On the other hand, positive pressure can help protect the people inside the room.
During the outbreak in 2020, many hospitals used negative air machines to create isolation rooms for the infected patients. These rooms were designed to circulate air through a fan and a high-efficiency particulate air filter.
The goal of this method is to create a lower pressure inside the room and prevent the pathogens from infiltrating the rest of the facility. One of the most important components of a negative air machine is its filter. This component is responsible for controlling the airflow inside the room.
Basics of Filtration
When using a HEPA negative air machine, the pre-filter must be designed to keep larger particles out of the air stream. This ensures that the machine can effectively filter the air. Having a pre-filter with a MERV of 8 can extend the life of a high-efficiency filter.
ULPA Micrometers Vs HEPA
The MERV rating system was established by the American Society of Heating, Air Conditioning, and Refrigeration Engineers to determine the effectiveness of a filter. High-efficiency particulate air filters, on the other hand, have ratings of 17 or above.
Aside from high-efficiency particulate air filters, various types of filters are designed to remove ultra-low particles. One of these is the ULPA, which has a MERV rating of 20. While they’re commonly used in healthcare facilities, the use of these filters in other applications is considered optimal.
Compared to the ULPA, the high-efficiency particulate air filters have less restrictive properties. This allows the fans in negative air machines to circulate air through them, which helps in controlling the airflow inside the room. Using the rating and size of the room as well as the airflow in the room, you can determine air changes that occur each hour with a negative air machine.
Why Room Sealing is Necessary
To effectively isolate a room, it must be well-sealed. To do this, you can use tape to secure various parts of the room, such as the air grilles and windows. This method can help prevent air leakage and maintain the air pressure differential. It can also cut down on noise and electricity consumption.
Electronic Pressure Monitoring
To monitor the pressure differential in a room, the facility must have a permanent device that’s capable of providing accurate and timely pressure readings. Although there are various types of pressure monitors available, electronic pressure monitors have various advantages, such as their sensitivity and accuracy.
Negative Pressure Room Configurations to Consider
A professional organization for healthcare engineering noted that multiple configurations can be used with negative air machines. These include the output of the device after passing through a filter.
- HEPA to Corridor
One of the most common configurations involves the use of a negative air machine to exhaust the air outside the room. This method requires a room’s anteroom or vestibule to be established, which allows the exiting air to be pumped into the corridor.
- HEPA to Outside
Another common configuration involves the use of a negative air machine to exhaust the air coming from the patient room through an external wall or window.
- HEPA to Return
Another option is to utilize a negative air machine to filter the air coming from the patient room through the return air grill of the HVAC system.
Before you buy a negative air machine, it’s important that you thoroughly compare the various features and functions of the device from different manufacturers. You will find that they all have differences in efficiency, quality, and features.
AUTHOR NAME : ALISON LURIE