Low and mid-range velocity VAV controller. Slow is sometimes better than fast…
Many demand oriented ventilation systems are facing one common problem. They are designed for operation with some nominal air flow volume that correspond to air flow velocities of a few meters per second in the duct. This is the sunny side of the life for the most ventilation systems, since the air flow is easily and precisely controlled by simple and affordable means like common VAV controllers.
Though, there are periods when just a tiny fraction of this nominal air flow volume is required.
Let´s point some examples for such demand oriented ventilation systems.
- Minimum ventilation for continuous limiting VOC and other pollutants from furniture, floor, cleaning agents etc. in e.g. schools, health care or residential premises during non-occupied periods with minimum possible energy loss.
- Cooled or heated spaces with precise temperature control by ventilation.
- Precise dosage of air specially treated e.g. by ionization, anti-microbial agents etc.
- Ventilation systems emphasizing energy efficient and environmental priorities.
During such operation periods the air flow velocities shall be measured deep below one meter per second. Here the most popular control methods hopelessly struggle against massively increasing imprecision.
We have found a method that helps overcome the low velocity control problems.
We have developed a new VAV controller OPTIMA-LV-R with moving measurement probe.
All the basic and advanced functionality is packed in a VAV-box with compact actuator/controller unit hard to distinguish from the standard VAV control devices.
Though, some of the features make OPTIMA-LV-R outstanding:
- Pressure independent compact variable air flow controller - electronic type.
- Control range of air flow velocity 0,2 - 6 m/s (velocity in equally sized duct)
- Adaptive measurement probe for high efficient dynamic pressure readings on whole velocity range
- Advanced algorithm for appropriate air flow control even at subliminal duct static pressure (2 Pa)
- Operable at ∆P range 2 - 600 Pa
- Lowest possible cross section restriction for given pressure and flow parameters resulting low pressure loss and low noise
- Accuracy with deviation app. 5% of the measured value.
- Leakage class 4C acc. to EN 1751 at pressure up to 1000 Pa
- Complete set of operation and override functions (Open, Close, Vmin, Vmax)
- Sizing: For air duct diameter 100 - 400 mm