VRA consists of a FRA measuring unit and a DJP type damper put together to form a complete unit. VRA is used for volume flow regulation in rectangular ducts, either for constant volume flow with step control, e.g. controlled by a switch or clock, or for variable volume flow, where the volume flow varies between a defined minimum and maximum limit. The actual volume flow is determined by a control signal from, for example, Regula Combi, BMS or another FRA/VRA. VRA-UNI consists of a regulator (Belimo VRD3) with a manual setting and motor. VRA-MP is equipped with a regulator and motor in one unit (Belimo NMV-D3-MP), which is programmable and has MP bus. VRA-SPR consists of a regulator (Belimo VRD3) with a manual setting and motor with a spring return. Further documentation on the diffusers can be requested from Lindab.
- Requires minimal initial pressure (Less than 20 Pa at Vnom)
- Has large regulation range
- Simple adjustment
- Damper tightness class 3
- Establismént of over/underpressure or pressure balance in the ventilated zones