humiFog (SL) NA
humiFog for direct humidification in the room is an adiabatic system that atomises the water directly into the environment being humidified. Another important application is adiabatic cooling: a 100 kg/h humiFog can cool the air with an equivalent cooling capacity of 70 kW, with an energy consumption of just 955 W.
Thanks to the low energy consumption, the large capacity, and the low maintenance, humiFog is the ideal solution for direct humidification in rooms.
The main components of the humidification system are:
• pump assembly;
• water distribution and atomisation system:
- distributors in the room;
- solenoid valves;
- connection pipes and fittings;
• water treatment system (reverse osmosis), not supplied by CAREL.
Pump assembly for direct humidification in the room
The pump assembly used for direct humidification in rooms has a constant speed volumetric pump that pressurises the water to 70 bar.
A special regulating valve is used to maintain the pressure constant as the water flow-rate delivered by the pump assembly changes.
The built-in controller completely manages the operation of the unit, using water pressure (in and out), temperature, conductivity sensors, etc.
In addition, it can independently control the humidity of the air in the room by simply connecting an external humidity probe. Alternatively, it can be controlled by a signal coming from an external control system.
The capacity is controlled directly by the humiFog unit, with stepped modulation. The pump assemblies are available with various maximum capacities, 60, 120, 180, 250, 350, 500 kg/h (custom versions up to 5000 kg/h).
A pump assembly is also available with multiple distribution systems located in different rooms: in this case, the pump assembly acts simply as a generator of water at constant pressure, while the distribution systems in the various rooms are managed by external controllers.
Independently of the distribution system used, the water is always delivered at constant pressure, 70 bar, to ensure that the nozzles always produce very fine droplets, with an average diameter of 10 to 15 µm, that are quickly absorbed by the air.
The nozzles are available with capacities of 1.45 kg/h, 2.8 kg/h and 4 kg/h at 70 bar.
This consists of stainless steel manifolds (pipes) with nozzles that are installed inside the room being humidified/cooled. The manifolds are available in various models, to fit nozzles from one side only or on two opposing sides. A series of manifolds make up a line in the distribution system.
Ventilated room distributor
This consists of a tangential fan located behind a manifold (pipe) with nozzles. The tangential fan generates a flow of air that assists the evaporation of the droplets and the sustains the droplets with a cushion of air, so as to produce an essentially horizontal trajectory. The ventilated distributors have capacities that reach 32 kg/h in just 1.5 m in length!
The ventilated distributors can be connected in series to make up a distribution line.
Capacity control and drain solenoid valves
Each distribution line, with or without ventilated distributors, can be connected directly to the pump assembly or shutoff by a solenoid valve. By controlling these solenoid valves, humiFog manages the capacity of the distribution system, thus obtaining stepped modulation in the capacity (up to 4 steps). Each line has a drain valve that is mainly used to quickly discharge the water pressure when the line stops atomising: when opening the drain valve, the pressure quickly drops from 70 to 0 bar and the line is emptied, preventing the nozzles from dripping.
In addition, the drain valves are used for the periodical automatic washing cycles managed by humiFog. The main drain valve, installed at the lowest point in the installation, is also managed by humiFog.
Connection pipes and fittings
CAREL provides hoses or stainless steel pipes and compression fittings suitable for pressures of up to 100 bar.
Observations on installation
humiFog is the ideal system for direct humidification into rooms because, by maintaining the water pressure constantly at 70 bar, it generates very fine droplets with an average diameter of 10 to 15 µm that are quickly absorbed by the air, humidifying and cooling it.
Each nozzle creates a cone of droplets that requires a certain time and distance to be completely evaporated.
This depends on the air conditions: for example, at 20 °C and 50% rH and with no air flow, the droplets will have a parabolic trajectory that will cause some of the droplets to carry up to 2.5 m horizontally and 4 m in height.
This clearly means there are limits in the installation to prevent the droplets from wetting objects, machinery and people in the room.
When these limits are not satisfied, use the ventilated distributors that, due to the cushion of air generated by the built-in tangential fan, carry the droplets of water in a substantially horizontal trajectory.
Special attention has been paid to the hygiene aspects of the humiFog.
The built-in controller automatically manages the following operations:
• fills the lines only when humidification is required;
• empties the lines when no humidification is required;
• automatically washes the lines at periodical intervals, when no humidification is required for an extended period.
This all ensures high hygiene standards, without requiring manual washing and/or emptying procedures
• printing industry;
• textiles industry;
• timber industry;
• fruit/vegetable cold stores;
• paper, timber stores, etc.
• industrial, especially in the textiles industry;
• outdoor cooling.