When you are doing construction, renovation, or even heavy cleaning, a negative air machine can actually be a necessary type of equipment. This type of machine uses air flow to set up a negative air pressure situation. With negative air flow, air flows into a space from surrounding rooms but the air from the space does not go back into the surrounding rooms. Typically, air flows back and forth between different spaces. However, if you have a space that contains contaminants, you do not want the air to flow back and forth into clean spaces. By drawing clean air in, you can scrub the air and expel it out of the building for a negative air flow.
The use of a negative air machine helps to contain contaminants. When would you want to use this type of setup? The simplest form of a negative air flow is to enclose a room with plastic sheeting and then put a box fan in the window to draw air out of the space. This type of system is actually pretty effective in keeping dust out of adjacent areas. When it comes to doing construction in hospitals and other medical facilities, this won't cut it. You need a complete system that take the construction debris and prevents it from ever entering the space where patients inhabit. This same concept is necessary for data centers with millions of dollars in IT equipment.
In major construction projects, the use of a negative air machine is most likely seen in anteroom setups. These chambers offer an enclosed space between clean areas and construction areas. When someone exits the construction area, they enter this enclosed space. They can remove coveralls and go through cleaning procedures. To keep the air in this space clean, the negative air pressure is a necessity. It draws clean air into the space, draws dirty air out, and scrubs the air before releasing it into a neutral space. This helps to keep construction debris contained.
The most common use of a negative air machine in a hospital is in a dust containment cart. When opening up a ceiling or wall, maintenance workers risk releasing contaminants and debris into clean areas. By using a dust containment cart with a negative air flow, this problem can be avoided completely. Many hospitals have two or more carts on hand for simple maintenance tasks. It helps prevent problems from happening in the first place.