DD ceiling air coolers can be used with different refrigeration capacity of the condensing unit, used in the cold storage temperature of-18 ° c or so, as supporting the use of refrigeration equipment. DL series which applies to cold storage temperature 0 ?. Cooled storage of fruits and vegetables, eggs DD series is suitable for temperature of-18 ° c or so refrigerators, cold storage of frozen foods such as meat, fish; DJ series suitable for-23 degrees below freezing, frozen meat products