Danfoss compressors are used in the new ETT air conditioning units that maintain a constant temperature in Airbus aircraft while they are under construction or being serviced. This is a positive partnership in many ways, crowning 15 years of partnership between ETT and Danfoss for variable-speed solutions.
Since 2009, ETT has developed air conditioning units fitted with inverter compressors known as the ACU-SRV (air-conditioning unit - variable refrigeration system).
The company, a long-term partner of Danfoss located in Brittany, specializes in climate control equipment. They won a contract for mobile air conditioning units in response to a call for tenders by the aircraft manufacturer Airbus in the late 2000s. This application has been around for a long time, but the criteria for awarding contracts have changed considerably over the past 10 years. Flexibility, energy savings and precise temperature control during the manufacture and maintenance of aircraft are the determining factors - now more than ever before - when selecting equipment.
The internal volumes of the aircraft manufactured by Airbus vary according to the model concerned (A350, A320 etc.). Also, when Airbus tendered out the new air conditioning units in 2009, ETT proposed a system that uses multiple cooling circuits and compressors fitted in tandem. Tandem configurations are a very common way of modulating cooling capacity. The first ACU SRV-units used to modulate the capacity stepwise, depending on the number and type of compressors in parallel (25%-50%-75%-100%). The capacity modulation allowed by the units previously used, with semi-hermetic compressors, was more limited as there were 1 or 2 compressors per system.
