This document discusses using Carel ultrasonic humidifiers for humidity control in a small datacenter with in-row cooling. It notes the low ambient humidity conditions and evaluates using a humidifier to maintain the total moisture content within an acceptable range. The Carel humiSonic humidifier is highlighted as a compact, efficient option that can precisely control humidity levels using ultra-sonic vibrations to create very fine water droplets. Installation examples show it placed within in-row cooling units or in room corners to quickly distribute moisture as needed.

1. Carel ultrasonic humidifier
for In row cooling and Compact Datacenter

2. New specs and new needs for humidification
• Wider allowable humidity range
• Use of fresh air

3. Focus on a small datacenter with In row cooling
Low humidity for ambient conditions
 Installation in Scandinavia
 100 kW cooling power
 Temperature in cold aisle 24°C
 Design temperature in hot aisle 34°C
 4 units with full recirculation: water
temperature 15°C (higher than dew
point). No dehumidification
 No humidifiers installed: traditional
dimensioning would be 15-18 kg/h
 Minimum humidity in cold aisle: 32%
(@24°C it is 5,5 g/kg ASHRAE
minimum recommended)
 Humidity measured: 14,5% with 24°C
this is 2,5 g/kg
In
rowunit
racks
Hot aisle
containment

4. A new approach for dimensioning : Total Moisture Content
 Volume of the room: 200 m3
 Total Moisture Content in minimum-desired conditions:
0,6 vs 0,92 kg.
 Max moisture using recommended limit (60%r.h.) is
2,16 kg.
 Hypothesis: dehumidification performed by AC units in
transitory conditions but mainly by the infiltration of
fresh air with low humidity and diffusion phenomena
 Hypothesis for calculation: high infiltration 0,5 vol/h
(to keep into account diffusion and door open
condition)
 The equivalent is a reduction of 850 g/h. In 0,5 h the
humidity goes down from acceptable to minimum
value. Experimental data show slower reduction.
 With 4 kg/h humidifier the Total Moisture Content can
be brought from minimum to maximum in 15 minutes 100m3/h@-20°C
95%0,6g/kgabsH
100m3/h@
20°C
44%6,5
g/kgabsH

5. humiSonic: the compact ultra-sonic humidifier
humiSonic is an adiabatic humidifier that
utilises the ultrasonic vibrations technology.
Compact
Efficient
Precise
Hygienic

6. humiSonic: technical features
Nebulizer: very fine drops (Ø = 5 µm)
Low energy consumption (100 W for 1 l/h)
Water flow: 0,5 – 1 l/h (230 V)
Modulation according to request (1-100%)
Modbus connection
Up to 3 slaves managed
RO water not mandatory but recommended for datacenter

7. Example of Installation of humiSonic
in In row cooling unit
• Warmer and dry air in inlet
allows quick absorption
without dehumidification
• Coil used as re-evaporation
surface
• Possible evaporating
temperature control in case
of variable speed
compressor

8. Room installation
• Installation in the corners for a
quick distribution but 1 point is
enough for diffusion
• Use of diffuser and conveyor to
install in a box or niche
• RO water treatment is
recommended to avoid the diffusion
of dust and minerals and to reduce
maintenance

9. An whole range to solve your humidity issues
• Duct and Room
installation
• Up to 18 kg/h