What is Air Pressure and how is it measured?
Air pressure, also known as atmospheric or barometric pressure, is the force applied by air molecules as they press down on the earth and all other surfaces. This includes people, objects, and walls.
Many of us don’t think too much about air pressure, but it’s essential to the way humans live. When we breathe, we expand our lungs and reduce our internal pressure. Because gases tend to flow from high to low pressure places, air is then able to flow into our lungs. Air pressure also has many commercial uses such as tires, syringes, and airplanes.
There are various environmental factors which can affect air pressure in any given area, but some of the main ones are temperature and the density of the air molecules. Hot air molecules cause air pressure to increase because they exert more force, whereas cold air molecules are more dense so they don’t move as much.
Air Pressure is measured using a barometric sensor.
Why is it important to measure air pressure in offices and commercial buildings?
It’s important to measure air pressure in buildings and offices because an imbalance can cause discomfort to workers inside. When the air pressure outside a building is higher than it is inside, a phenomenon called negative pressure happens. In the summer months, warm air from outside will make its way inside–this may increase your cooling costs. In the winter months, cool air will instead be drawn in which can equally overexert your HVAC system and drive your heating costs up.
When the air pressure inside a building is higher than it is outside, the opposite phenomenon happens. Positive air pressure is considered to be ideal during the summer, because humid air is kept outside. However, during the winter, the more humid indoor air can be drawn toward the edges of the building (like the walls), where it may condense into moisture. This can cause mould and other related problems to appear.
Sometimes there are also legal requirements that dictate what pressure a room or space bust be kept at. For example some hospitals are legally required to keep some rooms under negative pressure, so contaminated air does not leak into uncontaminated areas. For example, rooms that contain patients with highly infectious diseases.