To define the importance of relative humidity in the air in contact with food, we should be aware of the effects that a lack of RH%, in particular, can cause.
For food products, the loss of RH% within refrigerated environments is important because, over time, they can lose weight and there is a variation in appearance and taste, as the amount of water the air has taken from the product causes significant changes.
Factors that influence the variation of HR%.
There are a number of factors that influence the variability of the excess or defect in relative humidity that affect these products within refrigerated enclosures.
- Sizing of the evaporator.
- Degree of use of this evaporator.
- Temperature differential ΔΤ (degree of temperature where the refrigerant liquid circulates).
- Location of the temperature-humidity measurement point.
- Air speed in the exhibition area.
- Ambient temperature and degree of humidity in the establishment.
- Solar or light radiation degree that affects the food.
OTHER FACTORS
- Typology of the foods exposed.
- Amount of time of the food in the exhibition or storage area.
- Entry temperature of the food in the cold room or display furniture.
- Distribution of the food inside the cold room or display furniture.
- Distribution of the food inside the cold room or display furniture.
- Type of packaging of the food on display.
Definition of some of these technical variables
Sizing from the evaporator:
It is one of the most important variables, the m2 of exchange surface of the evaporator, affects significantly on the degree of HR%. A correct sizing equals a reduced differential and, consequently, an adequate RH%. On the other hand, a smaller sizing would increase the temperature differential and the absorption of humidity would be more important, thus affecting the weight and appearance of the product inside the refrigerated chamber.
Degree of use of the evaporator:
If the refrigerant liquid in evaporation processes does not circulate in the totality of the evaporator (lack of gas, small hole or a problem in the expansion valve…), it would undermine the optimal yield and would end with the drying of the zone and, consequently, of the product.
We would also obtain adverse effects if this evaporator does not have effective contact with the air to be cooled or humidified.
Temperature differential ΔΤ:
Small temperature differences in the cold room or display/service furniture will always improve the efficiency in order to obtain a correct RH%. A wide temperature difference will affect the environment with a lack of humidity.
The correct room temperature and humidity level in the establishment:
An excessive or deficient humidity degree and temperature in the room, will affect the conditions of the exhibition area (if this is an open area) and also the condition of the product.