sometime it may be the product is not used as intended....at least for us that was the case for freezer......our biomed technician has been with our hospital for >25 hrs and he used to cover the area of the fan in the back so he did not have to clean every quarter.
After so many discussion , finally bio med department head intervene and stopped practice....... because of cover/filter, the compressor was working too much and it died and had to replace it in less than five years...not anticipating any problems. we have two freezers, three double door refrigerators, platelet incubator, small ref. for ER, two plasma thawer and a cell washer....all helmer and very happy.....