Technical Brochure Variable flow rate controllers VRFactive Square, with LTG map control For comfort ventilation applications (e.g. office rooms)

Content Page View of unit, application, measuring principle, 4 General description, connection, selection, applica- 5 tion ranges, control accuracy, installation recommendations Flow rates, minimum pressure differences 7 Airborne sound transmission 8 Nomenclature, ordering code 14 Dimensions stated in this brochure are subject to General Tolerances according to DIN ISO 2768-vL. The actual specifications are available as a word document at your local distributor or at www.LTG.net. The flow rate controllers VRE, VRF, VREactive and VRFactive are designed to be installed in air-conditioning systems...

Technical brochure • Variable flow rate controllers VRFactive, square Flow Rate Control Basics – Which Product for which Application? Plant types Variable Flow Rate Constant Flow Rate Units with variable flow rates (VVS) use electronic flow rate controllers providing the room with exactly the required air volume – according to function and energy efficency. Units with constant flow rates (KVS) use flow rate controllers maintaining a constant flow rate mechanically system-powered. Working with no wiring or external power supply, they provide convenient and cost-saving solutions. Measuring Methods...

Enhanced differential pressure in low air speed ranges View of unitApplication The flow rate controller VRFactive has been designed for use in rectangular air ducts to electronically control flow rate based on constant or variable set values, independent of the pressure in the air duct. The damper has a very short installation case depth. Casing sections match the recommended sizes for rec tangular air ducts according to DIN EN 1 505. Thus, the largest possible air flow section may be selected even in case of limited installation conditions. Flow rate control has been designed for air speeds...

Materials, finishes - Casing, damper and axie of galvanised steel - Measuring probes of aluminium - Damper bearings of POM plastic Accessories, special versions - 40 mm thick insulating case of mineral wool with a 1 mm sheet steel jacket - Sound absorbers, matched to the cross-section - Compact controller compatible with MP-Bus, Modbus or BACnet - Integrated NFC interface for diagnostic and parametri-zation via smartphone/app - Service tool ZTH for diagnostic and parametrization Additional accessories and special versions on request. - Damper pressure loss up to 500 Pa - If sound emission via...

© LTG Aktiengesellschaft, Grenzstrasse 7, 70435 Stuttgart , Germany VRFactive_eng_TP(01/21) Former editions are invalid. Subject to technical modifications. page 6 of 14

Vmjn - Minimum flow rate = lower limit of control Vnom - Nominal flow rate Apmjn - Minimum pressure loss © LTG AktiengeseUschaft, Grenzstrasse 7, 70435 Stuttgart , Germany Tel. +49 71 1 8201-0, Fax +49 71 1 8201-720, [email protected], www.LTG.net Former editions are invalid. Subject to technical modifications.

Technical brochure • Variable flow rate controllers VRFactive, square Airborne sound transmission without sound absorber Conversion to other model sizes is realised at the same throttle point of air speed and pressure loss using the ΔL values from the following chart. The values are applicable to the associated unit height H. LW Okt = LW Chart + ΔL LWA = LWA Chart + ΔL Δptot fm LW LWA LpA - Total pressure diff. - Octave mid-band frequency - Sound power level - Sound power level, A-weighted - Sound pressure level, A-weighted © LTG Aktiengesellschaft, Grenzstrasse 7, 70435 Stuttgart , Germany Tel....

- Total pressure difference - Octave mid-band frequency - Sound power level - Sound power level, A-weighted - Sound pressure level, A-weighted © LTG Aktiengesellschaft, Grenzstrasse 7, 70435 Stuttgart , Germany Tel. +49 71 1 8201-0, Fax +49 71 1 8201-720, [email protected], www.LTG.net Former editions are invalid. Subject to technical modifications.

Technical brochure • Variable flow rate controllers VRFactive, square Casing radiation without insulating case Δptot = 500 Pa Conversion to other model sizes is realised at the same throttle point of air speed and pressure loss using the ΔL values from the following chart. The values are applicable to the associated unit height H. LW Okt = LW Chart + ΔL LWA = LWA Chart + ΔL Δptot fm LW LWA LpA - Total pressuredifference - Octave midband frequency - Sound power level - Sound power level, A-weighted - Sound power level, A-weighted © LTG Aktiengesellschaft, Grenzstrasse 7, 70435 Stuttgart , Germany...

Technical brochure • Variable flow rate controllers VRFactive, square Casing radiation with insulating case Conversion to other model sizes is realised at the same throttle point of air speed and pressure loss using the ΔL values from the following chart. The values are applicable to the associated unit height H. LW Okt = LW Chart + ΔL LWA = LWA Chart + ΔL Δptot fm LW LWA LpA © LTG Aktiengesellschaft, Grenzstrasse 7, 70435 Stuttgart , Germany Tel. +49 711 8201-0, Fax +49 711 8201-720, [email protected], www.LTG.net Former editions are invalid. Subject to technical modifications. Controller and air...

Technical brochure • Variable flow rate controllers VRFactive, square Room sound pressure level calculation from controller sound transmission (excluding flow noise from the air diffusers) Insertion sound attenuation for the splitter attenuator type SDF-SM (optional, included in chart on page 8) fm ΔLW Okt System attenuation according to VDI 2081 fm Room attenuation Outlet reflection Branching attenuation for distributing the sound power over multiple rooms, Vroom = 540 m³/h fm ΔLW Okt = 10 x Lg Sample calculation sound transmission Given: VRFactive 500 x 200 with sound absorber type SDF-SM Vmax...

Technical brochure • Variable flow rate controllers VRFactive, square Room sound pressure level calculation from controller radiation fm Ceiling attenuation ΔLW Okt [dB/Okt] Room attenuation Sample calculation radiation Given: VRFactive 500 x 200 with insulation case Vmax = 1440 m³/h, equates to 4 m/s Δptot = 200 Pa Required: Room sound pressure level LpA from controller radiation Solution: fm Sound pressure level [dB/Okt] size 600 x 200 LW Okt Ceiling attenuation ΔLW Okt [dB/Okt] Room attenuation A-weighted sound pressure level A-weighted sum sound pressure level LpA = 35 dB(A) © LTG Aktiengesellschaft,...