Have you ever walked into a store on a hot day and noticed the glass door fridges covered in water? You’ve probably heard somewhere that it’s due to condensation, but what does that really mean?
If you ask a refrigeration technician, they will say the fridge is “sweating”. This is not a fault of the fridge but a natural byproduct of the heat-exchange cycle. We won’t get too scienc-ey, for the sake of keeping you awake!
The cause of the condensation is actually not the heat but more specifically the humidity. This is why this natural occurrence is a lot more common in a place like Hervey Bay and not Hobart. The further north we travel and deeper into tropical climates, the more humid the air typically becomes.
So what is humidity?
Humidity is basically the amount of water floating in the air. Tiny molecules of water vapor that float in the warm conditions and make the air feel thick. Try to imagine tiny water molecules rising and drifting through the air as they warm up. We learned in school that heat rises and similarly, water vapour does too as it gains temperature.
We can’t see these water molecules but we can certainly feel them and know that sticky residue left on our skin on a warm day in places like Queensland or South East Asia. So the air is thick with water, ok, why does that make glass door fridges and freezers sweat?
The fridges and freezers are much colder than their surrounding atmosphere. As much as 20° - 40°C colder in fact, so very simply, as soon as those warm water vapour molecules come into contact with the cold glass door, they condense. This means that the coldness makes the water vapour molecules increase in size and turn into a liquid form while also naturally binding together, as water droplets do.
More and more water droplets form on the glass, gain weight and eventually grow large enough to break the surface-tension and drip down the glass.
So how to keep the glass streak-free?
Simple... Heat the glass!
By heating the glass, you will stop the water vapour from condensing as soon as it comes into contact with it. There are many fridges and freezers which have heating strips embedded for this exact purpose. Think of the rear window of your car, those black/brown lines which demist the glass, same concept.
Next time you are in a cafe, look at the cake fridge and see if you notice the hair-thin lines running horizontally across the glass. Those are the heating filaments. Cake fridges are probably one of the most common applications of heated glass and that's how Starbucks keep their fridges dry and their cakes looking fresh from Manhattan to Manila!
Cake fridges are not the only type of fridge to have this type of heated glass. Many upright and under bench fridges and freezers have the same feature to keep the glass dry and your products perfectly displayed. The LG-1000 series is one of our most popular fridges. Available in white or black, hinged or sliding doors.
Other models in the LG range also have the heated glass feature as well as fridges and freezers from many other brands. Browse the site to find a model that suits your cafe or restaurant or drop us a line if you need a hand to find the right model.