(High Temp Walk-ins Only) are extremely important. Humidity is the amount of "Moisture" in the air. Typically, the Refrigeration process dries out the air within the Refrigerated space.
Moisture in a Walk-in Box ?
Who Needs it ?
That depends on the product that you are storing. Bakery and Floral Items require very high humidity, otherwise, the product would "Dry Out."
Bottled and canned goods can survive very low humidity conditions.
How do we control the humidity in a walk-in box ?
Picture this, inside the walk-in is the Evaporator Coil,
it is usually mounted on the ceiling and is used to circulate the air through the cooling coils, absorbing the heat loads and expelling the cold. The air that is entering the rear side ("Intake") of the evaporator coil is at a given
temperature, the air leaving the "Discharge" side of the coil is now colder than it was when it first came in through the "Intake Side." That Difference in Temperature is what as known as the "Coil TD" (Temperature Difference)
capacity of the evaporator coil. The Golden Rule is, the Greater the "TD," the LOWER the humidity will be.
Therefore, if one were to use a smaller evaporator coil (less money) and really crank up that "TD," it
would really cool that box down quick.....but don't plan on storing any Bakery or Floral goods in there and expect them to last because it will be a very "Dry" box.
To Effectively Increase the humidity, a much larger coil
surface is required to cool the same box at matched capacity, but with much less of a "TD." It takes a large coil area to accomplish this, which unfortunately, means more money.