Air humidification belongs to one of the fundamental air conditioning types. There are various processes that can be used for this. Traditionally, but no longer very relevant, humidification was performed through a contact humidification process. Humidification of the air (supply air flow) through comb humidifiers no longer corresponds to the current hygiene standards. However, comb humidifiers are still used for adiabatic exhaust air humidification. The maintenance of these systems is however relatively high and this type of humification is used less and less.
A second process is air humidification through steam. Hygienically advantageous and without temperature losses. This process is however very energy-intensive during the humidification. The steam has to be produced (> 100 °C), and much electrical energy is used for this. If steam is already present in a process chain, this process is very appropriate and is simple to implement.
The third process is air humidification through high-pressure atomizers. This process is very up to date and is often used. The standards have changed enormously, and the useful life has increased considerably. Many older models were replaced due to their lacking functional safety. In this process, high-pressure pumps bring (osmosis) water to a high level of pressure (for ex. 70 bar) and spray nozzles inject it into the air flow. This creates a fine mist that humidifies the air flow up to the saturation limit.
Mountair Humidos Humidification system with central pump
With the high-pressure atomizer (HPV) humidification system with central pump, the humidification of several systems – supply air as well as exhaust air – is enabled by a single central pump. The osmosis water delivered to the construction is thereby brought to a constant pressure by a high-pressure pump. A large performance range can be covered thanks to the frequency inverter for the pump motor and a minimal circulating amount in the pump unit.
In the individual zones, the necessary amount of water is injected into the air to be humidified via several zone valves (digital circuit) and the nozzles. With four stage valves, 15 performance levels can be run 6.7% performance difference per level. Each zone valve is assigned to a drain valve. As soon as the humidifier switches off due to decreasing requirements, the drain valves are opened and the water can flow out of the spray bars. This means that no stale water can be injected into the air. This process is controlled by the slave controller that is located outside the Monobloc.
The humidification is performed adiabatically, which leads to a cooling of the air by the humidification. The main control is performed at the pump station. The current actual values can be viewed, and all ideal values can be entered and changed on a touch screen. From this central controller (master), all sub-stations (slave) at the spray bars with the humidifier racks and the individual zone valves in the Monobloc are connected via ethernet. The information from the slave stations is collected and processed in the central unit.
A Modbus connection to the building management system transmits the switching on orders, the values of the performances required and the current actual values of the system.
Hygiene requirement standards for supply air humidifiers have constantly increased. Past problems and the always higher requirements for fresh air in rooms have led to the products needing to distinguish themselves via certificates. In the field of air humidification, there are many brands, however not all of them will fulfil the currently required standards for long – for adiabatic, atomizing humidifier, these standards are defined as hygienic harmlessness according to VDI 6022.
The materials used must be microbially inert, the components must all be accessible, easily cleanable and upgradable. The humidifier system must also be able to be easily and completely emptied (area in the air flow with the atomizer nozzles), remaining water must be fully drained and must not be injected back into the air flow.
Mountair AG has launched its own high-pressure humidifier. Mountair Humidos is hygiene-certified according to VDI 6022. This enables the flexible use of our own humidifier system, in new installations or renovations.
Humidos high-pressure humidifiers are equipped with a controller. There is a master (high-pressure pump) and at least one slave (actual humidifier in the air flow) per Humidos humidifier. The master control cabinet is equipped with a touch panel and visualises the entire system. If several slaves are connected, they are represented on the touch panel according to the project. A slave control cabinet ensures the system-specific connection: zone valve control, assessment, air flow volume (fan), sensors and the ideal values indication from the BMS (0-10V signal).