AIR DISTRIBUTION
React Damper
Airflow control for demand control ventilation, temperature, humidity, and building pressurization
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.
Effect of Airflow Control in High-Performance Buildings
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.
Fig.1 Active Airflow Control System set up for demand control ventilation
Demand Control Ventilation
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.
Dynamic Building Air Balance
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.
Centralized Ventilation in Multifamily Residential Buildings
Using central ventilation in multifamily residential buildings offers a more efficient system, lower maintenance/operating cost, and fewer exterior wall penetrations compared to decentralized ventilation systems. Adding active airflow control to the design approach allows:
- Set back, Normal, Boost airflow levels (20–50% above normal airflow) by the apartment to enhance IAQ
- Free cooling (economizer) to reduce energy usage and improve carbon footprint by avoidance of running mechanical cooling in shoulder seasons
- Balanced airflows to manage infiltration/exfiltration
- Humidity control with a Boost Plus option with up to 100% above normal airflow
Swegon React Damper
The Swegon React Damper is a critical component of an active airflow control system. It offers:
- Pressure independent airflow control
- An easy-to-configure unit mounted controller (no need for tools or additional software)
- Airflow monitoring
- Taps for initial airflow balancing/commissioning for airflows as low as 11 cfm at 0.15 in. w.c.
- Very low air pressure drop while maintaining high turn-down for added energy savings and reduced sound levels
- 5% airflow measurement accuracy to deliver the required airflow and meet IAQ goals
The React Damper can be used for
- Temperature control
- Humidity control
- Demand Control ventilation (CO2, VOC or occupancy)
- Multifamily apartment airflow control including Passive House setback-normal – Boost requirement
– Also offers the option of free cooling/economizer and winter humidity spike control in air tight
buildings. - Constant airflow (in a VAV duct system)
- Constant pressure (in a VAV duct system)
The React Damper is available in:
- Round 04 – 24 in. (11 – 6,120 cfm)
- Rectangular 6 × 6 – 48 × 28 in. × in. (50 – 16,800 cfm)
Click here to learn more about Active Airflow Control
Control Damper Basics
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