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The Humidity Level in a Flower Cooler

Bonnie Grant

Cut flowers require special care to preserve the color, fragrance and texture of the blooms. Florist shops use special refrigerators to provide the optimum temperature, humidity and airflow that will keep flowers looking their best. A good floral cooler can extend the life of cut flowers, maximizing inventory and profit.

Humidity Effects

Artistic arrangement is only one aspect of elegant floral bouquets.

Proper humidity is provided in a flower cooler. It is necessary to maintain moisture in the plant tissues that keep the flower fresh looking. Good humidity has the same results as correct watering in pot-bound plants. All organisms need water to survive. Once a flower has been cut, it will die, but the process of deterioration is faster in some species than others. Humidity slows the deterioration by lessening dehydration. A regular refrigerator is not adequate to preserve flowers as it doesn't have a hydration unit.

Humidity Settings

Temperature and air circulation are constantly regulated in a floral cooler. They are two very important aspects, but the hydrometer is a crucial element for freshness. The optimum level of humidity is 93 to 95 percent, but an acceptable minimum is 80 percent. The evaporator coil is the method employed to provide correct humidity. It transpires moisture into the dry air of the cooling unit. The colder the unit is set, the higher the humidity level has to be to combat the drying effects of cool air.

Factors Affecting Humidity

Refrigeration and the fans in the units steal the humidity from the ambient air in the cooler. The humidity level will fluctuate with the opening and closing of the doors. A floral cooler should have a gauge attached for monitoring humidity levels. Changes in temperature that occur with use of the unit contribute to evaporation and can cause drying conditions. The temperature differential is the difference between the interior of the unit and the coil. With adjustments in temperature by even 10 degrees, the humidity loss is 20 percent.

Case Size

Case size affects the humidity levels of a flower cooler. Oversized coolers do not have the capacity to cycle the required cold air and provide relative humidity. A large cooler will have to run constantly and will still not be able to perform at proper levels. One way to combat the issue is to use a combination cooler. Coolers with separate refrigeration compartments are not opened as frequently, which means the temperature remains at a constant -- and preserves humidity -- longer.