Air Handling Systems, UK

Indirect evaporative cooling for packaged AHU

Condair evaporative humidifiers have been selected by AHS (Air Handling Systems) to provide evaporative cooling in the innovative OptEvent™ air handling unit. The humidifier cools the return air with low energy cold water humidification in this packaged heat recovery system that has been independently verified by BSRIA.

Working on behalf of a leading and progressive London children’s hospital, AHS was tasked to develop a packaged liquid-coupled heat recovery system to meet the hospital’s demands for hygiene, comfort and energy efficiency. The result was OptEvent™ which packages a Condair evaporative humidifier with an AHU and includes a pre-programmed ECM (Energy Control Module) that constantly ensures the minimum amount of energy is used to meet the air requirements.

Read more about the Condair ME

As return air passes through the evaporative humidifier, moisture is absorbed by the air and it is adiabatically cooled to as near 16°C as possible. This humid cool air is then used to chill the incoming fresh air with the use of a heat recovery system. By pre-cooling the incoming fresh air in this way substantial savings in energy costs can be achieved compared to compressor driven technology. The system has been independently verified by BSRIA whose testing of the technology supported AHS’s claims for energy recovery of up to 90% in winter and 40% in summer.

AHS was confident that the evaporative humidifier, supplied by Condair, would meet the OptEvent’s™ stringent energy efficiency specification. Wes Campbell, technical director, commented: “Air Handling Systems and Condair have a long track record in working closely together. The evaporative humidifier is a simple but very versatile model and its cooling capability was a vital ingredient in the development of the OptEvent™.”

As the water evaporates instantly from the humidifier, there are no aerosols or absorption distances to accommodate inside the AHU. This allows the humidifier to be fitted in very short sections without any danger of humidity wetting-out on ducts.

Hygienic operation of the humidifier is assured through the use of drain and purge cycles. By preventing water from remaining in the system, bacterial growth is limited. These cycles are adjustable depending on use and water quality to minimise water consumption. For added protection, the evaporative matrix is impregnated with silver, which has a powerful antibacterial action and there is an optional silver ion dosing system and UV sterlisation.

The Condair in-duct evaporative humidifier adiabatically cools return air to ~16°C as it evaporates water through a silver-impregnated antibacterial matrix, then transfers this free cooling to incoming fresh air via heat exchanger – achieving up to 90% energy savings in winter and 40% in summer for the hospital's OptEvent™ AHU.

Condair in action

Projects and references

Bloomberg

The European headquarters of the media company Bloomberg in London was designed by the architects Foster + Partners and opened in 2017. The building complex is one million square meters in size and has many details that have been the result of months of research and development, such as a ceiling decorated with petals that provides lighting and cooling, but also acoustic insulation.The building consists of two ten-story blocks connected by a bridge. An arcade of restaurants selected by Bloomberg's restaurant critics runs between them. The building uses 70% less water and 40% less energy than conventional office buildings and was even awarded the Stirling Prize in 2018.Condair ME evaporative humidifiers are maintaining the ideal indoor humidity for the preservation of the wooden interiors and a healthy environment for visitors.

San Francisco Museum of Modern Art

A nonprofit organization, SFMOMA holds an internationally recognized collection of modern and contemporary art and was the first museum on the West Coast devoted solely to 20th-century art. The museum's current collection includes over 29,000 works of painting, sculpture, photography, architecture, design, and media arts.

University of Edinburgh

The University of Edinburgh, founded in 1582, is the sixth oldest university in the English-speaking world and one of Scotland's ancient universities. The university is deeply embedded in the fabric of the city of Edinburgh, with many of the buildings in the historic Old Town belonging to the university.Condair is proud to be supporting the University of Edinburgh across various facilities with electric steam and evaporative humidifiers.