5.2.1. Ventilation units for mixing ventilation LG-Z-M-LB and LG-ZUM-M-LB, for horizontal floor mounting

Decentralized air conditioning via the building facade.
To air condition office and administrative buildings having facades with floor-to-ceiling glazing, Krantz supplies ventilation units for raised floor mounting; they provide the required minimum percentage of outdoor air and remove the internal cooling and heating loads. The unit type LG-ZUM-M-LB has an additional function with recirculated air.



Supply air volume flow rate 33 l/s [120 m3/h]
Supply air temperature, summer

18 °C (with outdoor air 32 °C / 40% relative humidity)

Total cooling output: including 560 W
– for cooling down 33 l/s [120 m3/h] of outdoor air 240 W
– for cooling a room with tR = 26 °C 320 W
Chilled water temperature 15 / 17 °C
Supply air temperature, winter 34 °C (with outdoor air –12 °C)
Total heating Output: including 1 840 W
– for heating up 33 l/s [120 m3/h]
t= 22 °C of outdoor air
1 360 W
– for room heating with tR = 22 °C 480 W
Hot water temperature 50 / 40 °C
Control signal for fan speed 0 – 10 V DC
Effective power of fan 20 W (for volume flow rate = 33 l/s [120 m³/h])
Operating voltage 230 V / 50 Hz


  • Outdoor air intake directly through the facade; return air extraction via central system
  • Cooling and heating via air-to-water heat exchanger
  • Cooling with outdoor air (free cooling)
  • Mixing & displacement ventilation close to facade
  • Energy-efficient EC radial-flow fan
  • F7 class filtration of outdoor air