World cuisine is celebrated in semi-open show kitchens, especially in the minimalist Japanese room. Its wall opens up with small, sharp-edged openings. A slightly ascending path leads guests to a room for Japanese ceremonial dining. A cigar room with a walk-in humidor and the Cheesetower, where cheese matures in a cave climate, are stations on this journey through different climate zones.

Twelve Dual 2 units from Condair control the humidity in the hotel rooms. A unit for 24,000 m³/h supply air was installed in the ventilation system of the main restaurant.

The design case is winter with - 15 °C and a relative humidity of 90 %. The air is preheated to 38 °C so that it is still 21.5 °C warm after cooling humidification to a comfortable 45 % relative humidity. Adiabatic humidification is the most energy-efficient technology.

High-pressure humidifiers require considerably more energy for their booster pump, as do steam humidifiers for their water heating. Dual 2 also saves humidification water. Rinsing water losses are minimal. The amount of water can be precisely controlled.

Challenge: Hygiene

Wherever air is saturated with water, great attention must be paid to hygiene. Neither legionella, molds, yeasts nor other germs are allowed to multiply. The Dual 2 hygiene concept effectively eliminates all these organic contaminants.

The core of the hygiene concept is silver ionization. Just as silver tabs sterilize drinking water, the silver ions and a sterile filter permanently prevent the growth and spread of germs and the formation of biofilms. Inorganic impurities are removed by a fine filter, water softening and reverse osmosis.

The conductivity of the water is monitored automatically. The water circuit is regularly flushed even at times when no humidity is required, thus counteracting the formation of germs.

For the humidification itself, the hybrid humidifier combines atomization at low pressure with post-evaporation. The water droplets are completely evaporated on ceramic elements, which are as porous as a sponge and therefore have a very large surface area. The humidified air no longer contains any aerosols. And it is virtually germ-free.

The hygiene of the Dual 2 in operation has been proven and confirmed in a long-term test by the independent Fresenius Institute. Hygiene is checked again after one year of operation. After the system is switched off, the spray circuits are emptied automatically. Due to the low-pressure system, the humidification distance is extremely short and the system is very compact.