Controlling and monitoring indoor levels of carbon dioxide is essential for everyone’s health, safety, and the energy efficiency of buildings. Similar to how we need to breathe fresh air, so do buildings. Ventilation in a building is the essential process of replacing stale air with fresh air. Without engineered ventilation, buildings become susceptible to stagnant air, mold, bacteria, and potentially harmful gasses like radon, VOCs (volatile organic compounds), and carbon dioxide. Prolonged exposure to these elements can lead to “sick building syndrome” where occupants experience acute health and comfort effects.
- Air pressure and how it affects commercial buildings
- Effects of not managing building air pressure correctly
- How to control the air pressure
- Measuring pressure
- Installation advice and setpoints
Air pressure is the weight of air molecules pressing down onto the earth and objects. (refer to Figure 1). For instance, cool air molecules are heavier and denser causing the force applied to a structure to be greater while warm air molecules are lighter and have lesser force on the building. There are other complicating factors such as wind, weather and seasonal changes, which will also produce variations in pressure.
In HVAC systems, sensors measure controlled variables of temperature, humidity, pressure, and air quality. Sensor inputs connect to the Direct Digital Control (DDC) system and network to the Building Automation System (BAS). High quality sensors are the foundation for ensuring occupant health and comfort and are essential for energy efficiency within buildings.
HVAC system performance and comfort rely on accurate measurement and control of differential pressure. Effective air distribution is achieved by closely monitoring and controlling air pressure. By monitoring the airflow pressure across dampers, filters, fans, and between rooms, the HVAC system can efficiently and economically optimize building performance and reduce energy consumption.