Evaporative Cooling

Adiabatic Humidification and Evaporative Cooling System

Centrifugal humidifiers – humiDisk

  • Simplicity: requires just the 230 Vac power supply and the mains water and drain lines; operation is ON/OFF;
  • hygienically safe: very small water tank, just 55 ml; washing procedure at unit start; emptying at the end of the humidification cycle; washing procedure at the beginning of every cycle (with CAREL control panel only);
  • modularity: 1 or 2 humiDisk65 units can be controlled in parallel using the special control panel, or up to 10 humiDisk10 units using the CAREL humidistat
humiDisk is a small yet sturdy humidifier that uses a spinning disk to atomise water and transform it into millions of very small droplets that, blown by a built-in fan, are introduced into the environment, where they evaporate, humidifying and cooling the air.

General Characteristics

Very low power consumption
humiDisk is a simple, economic and easy to maintain humidification system, with an energy consumption of just 220 W for 6.5 kg/h of capacity (31 W for the 1.0 kg/h model).
Guaranteed hygiene 
The water tank inside the humiDisk contains just 0.055 litres of water, which is atomised, at maximum capacity, in just 30s for the 6.5 kg/h model and 3 minutes for the 1 kg/h model. The water in the tank is therefore changed very rapidly, meaning the humidifier substantially works with non-stagnant running water, so as to guarantee the best hygiene conditions.
Adjustable capacity (humiDisk65 only)
Operation of humiDisk65 controlled by an electronic board fitted with a trimmer for setting humidifier capacity, from 1.1 to 6.5 kg/h, making it suitable for all applications.
Automatic washing cycles (humiDisk65 only)
The board, as well as managing normal unit operation, also performs a tank washing cycle when starting the unit, and an emptying cycle when humidification is no longer required. This avoids having stagnant water inside the unit.
Important: to ensure a higher level of hygiene, when using the CAREL electrical control panels, the humidifier also washes the water tank at the start of each humidification cycle.
Water used
humiDisk can operate on both mains water or treated water. The quantity and quality of the minerals dissolved in the water affect the frequency of the routine maintenance operations and the amount of dust generated. For best operation, use demineralised water (do not use softened water, as this does not reduce the content of minerals dissolved in the water). In any case, observe the requirements of UNI8884 standard “Characteristics and treatment of the water in cooling and humidification circuits”, according to which the main characteristics of the water are conductivity < 100 μS/cm and total hardness <5 °fH (50 ppm CaCO3). Similar requirements are also specified in standards VDI6022, VDI3803.
Ultrasonic humidifiers – humiSonic

The CAREL solutions developed using the latest ultrasound technology can guarantee numerous benefits in many applications:

  • energy saving: just 10% of the power consumption of steam humidifiers;
  • reliability: 10,000 hours of uninterrupted operation guaranteed;
  • precision: relative humidity control of ±1% on the set point;
  • absorption efficiency: the droplets, just 1 µm in size, evaporate instantly;
  • easy installation: in the basic configuration, humiSonic is a plug & play solution;
  • maximum hygiene: no water recirculation and periodical washing cycles.

General Characteristics

The new humiSonic range comprises two versions, meeting the needs of all applications: humiSonic compact, small enough to be installed on a fan coil, and humiSonic direct, for room distribution.

Ultrasonic humidifiers feature a small water storage tank and piezoelectric transducers installed at the bottom of the tank. The surface of the transducer vibrates at very high speed (1.65 million times a second), a speed that does not allow the water to move due to its inertial mass. During the negative amplitude of the transducer cycle, a sudden void is created that brings about the production of microscopic bubbles, which are pushed to the surface of the water during the positive amplitude of the cycle. This effect is called cavitation.

During this process, the resulting intersecting sound waves created directly underneath the surface of the water cause very small droplets of water to separate, forming a fine mist of vapour that is immediately absorbed by the flow of air.

This ultrasound technology applied to CAREL air humidification solutions is efficient, reliable and versatile:

  • efficient, as ultrasonic humidifiers guarantee energy savings of 90% when compared to ordinary steam generators;
  • reliable, as humiSonic is guaranteed for 10,000 operating hours when running on demineralised water;
  • versatile, thanks to the size of the droplets produced (average diameter of 5 µm). This fundamental characteristic guarantees very fast absorption of the atomised water in the room or duct, avoiding possible condensation.
Compressed air water atomisers
The master slave configuration can be used for:
  • high capacity: applications in rooms or ducts where more than 230 kg/h of humidification is required, and thus more than one mc cabinet. The control signals (probes, external signals, limit probe) are connected to the master only. The master and the slaves generate a humidification/cooling capacity that is proportional to demand and their capacity. This allows systems to be developed with a capacity up to 1380 kg/h;
  • multizone applications: applications in multiple zones, rooms or ducts, each with its own humidity/temperature set point. All the parameters, status information and messages for all the cabinets can be viewed and edited from the user interface on the master. Installations in large spaces can be divided into zones, each with their own humidity/temperature probe, using the multizone master slave system.
  •  Automatic nozzle self-cleaning system: each cabinet, master and slave, periodically activates a cycle for drying and cleaning the atomising nozzles. A special cleaning piston inside the nozzle is periodically pressed, by a spring, into the opening of the nozzle, removing any mineral salts and considerably reducing the need for cleaning.

General Characteristics

Compressed air humidifiers are the ideal humidification solution whenever a compressed air supply is available, as is the case in many industrial applications, even if humidification systems are often fitted with a dedicated air compressor. The humidifier essentially consists of a cabinet fitted with electronic controller that, using two independent connection pipe networks, supplies the spray nozzles with compressed air and water at the ideal pressure for instant operating conditions. The units can be installed inside an AHU or directly in the room where humidity needs to be controlled. The greatest advantage of these atomisers is the minute dimensions of the droplets produced and their thorough mixing in the compressed air that, due to its speed, distributes the aerosol in the room and consequently allows quick absorption. These units can therefore be readily used for direct cooling in rooms, and are ideal for the textile industry, wood and paper processing, and storerooms, where there is almost always a supply of compressed air.

mc multizone features an electronic controller that manages the supply of water and compressed air to the nozzles.

Water atomisation is managed by an external control signal or, in the case of stand-alone control, so as to maintain the humidity/temperature set point. The unit also manages a series of automatic cycles, such as nozzle cleaning and washing.

The system has the ability to control humidity independently in multiple zones (rooms, AHUs, cold rooms) using a masterslave layout. The layout has one master and multiple slaves (up to 5) connected in a pLAN. The master is fitted with a display for accessing the readings, viewing the status and messages on the master and slaves. The slaves have their own internal controller and can be set to continue operating even if connection to the master is interrupted.

Pressurised water humidifiers
  • very low power consumption: consumes just 4W per l/h capacity, less than 1% of any steam humidifier.
  • summer/winter operation: humidifies the air during winter, cools the air in summer by direct and indirect evaporative cooling.
  • choice of models available: single zone or multizone to best satisfy different requirements.
  • high capacity: standard models are available with capacities from 100 to 600 kg/h and custom models up to 5000 kg/h.
  • maximum hygiene: suitable for all applications that require a high level of hygiene.
  • “silicon free” version available with steel pump for painting applications.

General Characteristics

Pressurised water humidifiers exploit the potential energy transferred to the water by a special volumetric pump in the form of high pressure (generally 70 bars), so as to achieve very fine atomisation through special nozzles.

The most common application of these humidifiers is in AHUs, where the pressurised water distribution system is installed. In industrial environments for processing wood or paper, or in the textiles industry, systems are often used to distribute atomised water directly into the rooms. As well as humidity control, pressurised water atomisers are the best solution for fully exploiting the potential offeredby evaporative cooling, both direct and indirect, inside AHUs or in rooms, as in the case of industrial facilities and large public spaces, such as metropolitan railway stations and airports.

One crucial aspect is the hygiene that pressurised water humidifiers must guarantee in the application where they are used. Management of washing cycles, the materials used and the configuration of the atomised water distribution system are the main features that guarantee CAREL humidifiers comply with the strictest hygiene regulations in force (VDI6022). humiFog multizone represents the new generation in high pressure atomised water humidifiers.

A volumetric pump sends water at high pressure to a distribution system made up of nozzles that atomise the water into very fine droplets, which can be absorbed by the air in a very short space.

Energy saving

The only energy humiFog consumes is used to power the water pump, just 4 watts for every l/h of capacity. Cooling in summer is provided by lowering air enthalpy, while humidification in winter has the advantage of being able to use thermal energy at low temperature. Power consumption is thus minimised. In addition, an inverter is used to modulate pump speed, meaning both more precise control and even lower power consumption.

Adiabatic Atomizer Humidifier

chillBooster

  • energy saving with very low return on the investment
  • easy to install and to use, simply control chillBooster with a remote on/off
  • flexible shape and capacity of the distribution system thanks to a very wide range of accessories available
  • management of solenoid drain valves to drain the piping

General Characteristics

chillBooster is an adiabatic atomizer that uses evaporative cooling to cool the air before it is used by the condensing units such as chillers or dry coolers. The atomization of water in micrometric droplets favours spontaneous evaporation, which takes away part of the the thermal energy required for the evaporation itself from the surrounding air, lowering its temperature (each kilogram of water that evaporates absorbs 0.69 thermal kW from the air). Bringing the air close to its wet bulb temperature means that, during summer, its temperature is lowered by approximately 10-15°C with a consequent reduction of the workload required from the condensing unit (chiller), and therefore a significant energy saving in terms of spared electric kW. chillBooster essentially consists of a cabinet with pressurizing pump (10 bar) and a system of nozzles mounted onto steel manifolds to be arranged around the condensing unit: the atomization occurs against the flow, so that the droplets, sucked in by the fan of the chiller, follow a longer route and have more time to evaporate. In this way, the air is cooled and the heat exchange of the battery is increased in depth. A part of the droplets will wet the flaps of the battery, absorbing the heat and then evaporating, thus increasing the heat exchange.
chillBooster can be used during summer, for maximum global energy saving, or it can be used to cut the peaks of maximum load on hot days, to maximise the efficiency of the chiller. As well as for retrofit applications, you can consider the effect of chillBooster also during the planning stage, by selecting the smallest, cheapest chiller with the lowest energy consumption. chillBooster is available in the capacities: 100, 500 and 1000 l/h. The nozzles have a capacity of 5 – 7.5 – 15 l/h. chillBooster can be used both with demineralized water and mains water, provided that the conductivity of the latter is not less than certain values.