The good conservation of chocolate is fundamental to keep unaltered both flavour and consistency. The chocolate does not like the temperature shocks. The low temperature, after hardening the inner part, makes it being covered of humidity and then opaque and translucent due to the sugar crystals climbed up the surface and melted in the steam to re-crystallize and all alterations are irrecoverable. On the other hand, the warm temperature makes the cacao butter melting that, once the temperature decreases, gets cold and crystallize, causing a whitish patina. Further chocolate alterations can be due to the conservation in presence of extraneous smelling products, that could be caught.The air conditioning installation should keep the warehouse at a constant temperature between 18 and 20°C, with a 55% of relative humidity.

These conditions have to be constant all over the year, independently from the external temperature reaching 10°C during winter and over 35°C during summer.

The external air renewal should be continuously filtered to avoid the supply of polluted air.

Naturally the continuity of the service will be a decisive factor on the system choice.

Special attention was paid to the total cost of the installation, to be reduced both during installation and in particular during the day-to-day management.
 

The building features and the specific boundary conditions have led to the choice of a decentralized system air to air, with packaged rooftop reversible heat pumps.
The units have been installed on the roof and control automatically temperature and humidity in the served area on the basis of the conditions that have been measured inside and outside the building.
The supplied, extracted and fresh air flows are managed through electronically controlled and direct coupled ventilation systems without belts and pulleys. It will be possible to set the required flow rate through the controller.
Cooling and heating are made by the cooling circuit on board, with an high efficiency reversible heat pump with thermodynamic energy recovery on the exhaust air.
The humidity control includes the free reheating device to recover hot gas for summer dehumidification and the steam humidifier with immersed electrodes for the winter operation. 
The Free-cooling is enthalpic and enables the free cooling by directly supplying the outdoor air as soon as the temperature and humidity are suitable to do that. 
The external fan are ECOBreeze type, with electronically controlled motor with permanent magnets.
 

Thanks to Clivet system, the Barcelona logistics warehouse  can supply regularly the commercial and industrial customers of Cémoi group in all the southern Europe.
The temperature and humidity control is automatic and economically advantageous, thanks to the high efficiency of the units and their energy recovery. 
The continuous remote transmission of the operative parameters via serial line confirmed the achievement of the required performances.

The decentralized solution by Clivet reduced considerably also the installation costs and has increased its versatility and reliability, because every served area is completely independent by the others.