Humidity Control Real Life Data
Real Life Data of eliminating moisture issues in a process freezer
If your business uses cold storage, cool rooms or process freezers, then the real-life data below should interest you. See definitive data on what simple changes to operations can make in creating or destroying the ideal climate.
Let’s look at data logger reports for a large food processing plant. The two graphs below are reports showing the humidity and temperature levels and fluctuations within an ante chamber adjacent to a blast freezer.
Client needed the consistent 60-80% humidity in their blast freezer to be brought down to 20% relative humidity (RH) and remain at 20% RH.
We used a data logger over a three day period.
This process freezer has automatic doors, strip curtains and a dehumidifier installed. However… door opening times were sometimes longer than necessary and strip curtains were pulled up and left up.
As you can see the humidity is all over the place (blue line). And condensation, fog and ice began to creep back into the storage area.
Below Graph - Same process freezer – data over a four-day period.
For the purpose of this report, we turned off the dehumidifier and turned it back on again.
This allows us to show you the difference in humidity levels once a commissioned dehumidifier is up and running.
Once the dehumidifier was running again, employees were mindful, so door opening times were reduced and strip curtains were not swung up.
SOLUTION ACHIEVED
After installation and commissioning of a dehumidifier a far more consistent humidity level is reached and maintained. Meaning fog and ice build-up were dramatically reduced along with energy consumption and production downtime.
Why Does Ice Build Up Happen?
Ice build-up is caused when moist air enters the cold store. Sometimes there can be thin layers of ice which has the appearance of snow. When the moist air comes into contact with cold surfaces such as floors, walls and evaporator coils, the water vapour in the air condenses to form water and then freezes to form ice.
Moisture typically enters the cold store or freezer during door opening times. As the doors open warmer, more moist air is naturally drawn into the cold store, which in turn causes fog, condensation, and ice.
Three Ways to Reduce Ice in Cold Storage and Process Freezers:
1. LIMIT NUMBER OF SECONDS DOOR IS OPENED EACH TIME.
Do not underestimate how much moisture enters the cold store every time the doors are opened. If you can reduce the number of seconds the door is open, you will significantly reduce the amount of moist air entering. Rapid doors on timers are a good idea. Or put in the practise of the shutting the door straight after you enter. Do not leave the cold store door open as you are packing or looking for product! It only takes 30 seconds of a door being left open to the ambient air for ice to start to grow on an evaporator fan.
2. INSTALL PLASTIC STRIP CURTAINS.
Plastic curtains are a good way to reduce the amount of air that enters the cold store during door opening times. The curtains act as a barrier so that it is harder for the moist air to get into the cold store. However, moist air will still get into the cold store through the gaps and when a forklift is running through the curtains.
3. USE A DEHUMIDIFIER TO ENSURE YOUR COLD STORE IS KEPT DRY.
The best way to ensure your cold store is kept as dry as possible and for ice build-up to be dramatically reduced is to install a dehumidifier. It dehumidifies the air as it enters the cold store. As the doors open, it captures the moist air, dehumidifies it, and supplies dry, low dew point air at the entry doors. This dry air is drawn into the cold store when the doors open and circulates freely across the floor to keep it dry.
If you would like to learn more about how Humiscope can help create the ideal climate for pharmaceutical manufacture and storage, visit our Pharmaceuticals Page