Environmental indoor thermal control of extra virgin olive oil storage room with phase change materials

The quality of extra virgin olive oil (EVOO) is strongly correlated to storage temperature, in fact the storage conditions (packaging material, oxygen, temperature, and light) alters not only the fatty acid alkyl esters (FAEE) of the olive oil but also other quality parameters such as peroxide, making the oil incompatible to the high quality EVOO. During storage of EVOO the polyphenols tend to decrease and compromise the dietetic and nutritional qualities and taste and produce harmful substances. The storage temperature, more than 24°C, influences quite a lot FAEE especially for long-term conservation. High storage temperature leads to degradation of oil quality in the long term while low temperature develops rancidity quickly, reducing the consumer’s demand. Low storage temperature also affects the EVOO quality but in a lesser way than high storage temperature. The present study proposes the use of a control temperature system based on the application of phase change materials (PCM) on the buildings envelope. A specific case study was considered to evaluate the effect on use of PCM. The building analysed was an olive mill building situated in Scido a small town in the province of Reggio Calabria located in southern Italy. The intervention on the EVOO storage room to improve the energy savings for temperature control was based on the insulation of the partitions and the installation of a false ceiling to limit the air volume, with a two layer panel sandwich, one of PCM and the other of a rigid polyurethane foam with a 4 cm thick metal cladding. A thermal analysis simulation, by means of DesignBuilder software, was conducted. To calculate the electric energy spent in a year to control air temperature in a range of 8- 22°C. The results were of 3590. 67 kWh/year for existing building and 2539.52 kWh/year for building with PCM, energy save of about 30%. A temperature decrease of about 3°C was measured inside the storage room without a cooling system during the hottest year period but the most important result was a thermal indoor air stabilisation in the storage room. This condition avoids a thermal fluctuation to the EVOO and it is the best storage condition.