React Damper

Varying the airflow to individual spaces (control zones) provides better control and thus higher occupant satisfaction.

The Swegon React is an active and pressure independent airflow control damper that can vary the airflow in response to dynamic changes in individual occupied spaces. The Application Guide provides detailed information on how to use the Swegon React Damper product line in a wide range of comfort and Indoor Air Quality (IAQ) applications.

Active airflow control is a piece of the puzzle that helps deliver truly high performance in the built environment. High performance can mean thermal comfort, indoor air quality (IAQ), energy savings, low carbon emissions and protecting the building envelope.

Active airflow control is a system of controls and components that can vary the airflow in response to dynamic changes in the occupied space. The major components of an active airflow control system include variable airflow fans, independent airflow control dampers with actuators, airflow monitoring and controls.

To achieve indoor air quality (IAQ) the right amount of ventilation air must be delivered and the exhaust removed from the occupied space. A constant flow ventilation system will deliver the ventilation air once properly balanced by a professional test and balance contractor. While IAQ may be achieved with a constant flow system the energy use, carbon impact and operating cost will be high.

The solution is to advance to a demand control ventilation (DCV) system. By adding active airflow control to the design, it is now possible to deliver just the right amount of ventilation air to achieve IAQ based on real time-space use. The rest of the time, the reduced airflow will deliver improved energy usage, low carbon emissions and reduced cost. To deliver DCV, an active airflow control system is used where each zone is controlled either by an occupancy, VOC, or CO2 sensor (See Fig. 1).

FIG. 2 shows actual ventilation airflow data and energy usage for an office building in Sweden. The system delivered the necessary IAQ while reducing the airflow on average to 42% of the design ventilation requirement resulting in greatly reduced energy use, carbon impact and operating cost. Real-world experience supports the demand control opportunity.

Whether the goal is temperature, humidity or IAQ control, the result is only as good as the system’s ability to get the right amount of air to the space. Fig. 3a shows how the space closest to the air handling unit will get more air than the room furthest away unless airflow control is applied. If the system is constant volume airflow, then manual balancing dampers can be used. For variable airflow, adding active airflow control the right amount of air can be delivered and extracted from each space (see Fig. 3b). Not only will this deliver the intended result (IAQ or thermal comfort) it will avoid over pressurizing the space, driving air into the building envelope and risking serious damage to the building.