Perimeter induction units – usually located under windows – blend primary air from the air-processing unit with secondary air from within the room. The high-velocity processed air delivery is induced into the unit through restrictive nozzles. This creates a negative pressure in its wake, drawing in the room secondary air for mixing and discharge. A damper regulates the volume of room air passing through a thermostatically controlled heating coil.
These coils may be used with chilled water as cooling coils in the summer months. If heating only is used, the system is known as the ‘two-pipe induction system’ With the additional two pipes for cooling water, the system is known as the ‘four-pipe change-over induction system’. The latter system gives excellent control of the air temperature in various zones but is very capital intensive, and therefore expensive to install.
FREQUENTLY ASKED QUESTIONS
The high-velocity processed air delivery creates a negative pressure in the induction unit through the restrictive nozzles. As the processed air is induced into the unit, it creates a region of low pressure behind it, which draws in the secondary air from the room for mixing and discharge.
The damper in an induction system regulates the volume of room air passing through the thermostatically controlled heating coil. This allows for precise control over the amount of secondary air that is mixed with the primary air, ensuring optimal indoor climate conditions.
A two-pipe induction system uses only two pipes for heating, whereas a four-pipe changeover induction system uses two additional pipes for cooling water. The four-pipe system provides excellent control of air temperature in various zones but is more capital-intensive and expensive to install.
The four-pipe changeover induction system provides excellent control of air temperature by allowing for both heating and cooling modes. During the summer months, the system can switch to cooling mode, using chilled water to cool the air, and during the winter months, it can switch to heating mode, using hot water to heat the air. This allows for precise control over the indoor climate in different zones.
Induction systems offer several advantages in commercial buildings, including energy efficiency, flexibility, and zoning capabilities. They can also provide a comfortable and consistent indoor climate, which can improve occupant productivity and satisfaction.
The induction system’s ability to mix primary and secondary air can improve indoor air quality by introducing fresh air from the air-processing unit while also recirculating and filtering the room air. This can help reduce the concentration of airborne pollutants and improve overall indoor air quality.
The induction system’s ability to mix primary and secondary air can improve indoor air quality by introducing fresh air from the air-processing unit while also recirculating and filtering the room air. This can help reduce the concentration of airborne pollutants and improve overall indoor air quality.
