Why does ice-build up?
Even at set points which are at an ambient temperature, in order to keep temperature regulated and controlled, the temperature at the evaporator is likely to be much colder.
Water particles are present in the air, and so the amount of water present in the unit increases with every door opening. This water when mixed with cold air then creates ice build-up on the units. If there are more door openings then ice is more likely to build up, therefore you are likely to need to run a defrost or tempering cycle more often.
How does ice affect the running of the unit?
Ice puts all components in the unit under more pressure and reduces cooling and operational efficiency. Due to the way ice forms, excessive build up can crush the evaporator coil. This means the unit is likely to breakdown, and can cause costly repairs, as well as leading to significant operational down-time.
What should I look out for? How do I look for it?
Although it seems obvious, look for any signs of ice on the unit. The most important places to check are the evaporator coil, this is inside the unit where the cold air comes from. In Blast Freezers this may be above a false ceiling, so please ensure that you use appropriate health and safety procedures to check this area, and don’t cause damage to the false ceiling. Ice can also build up on the floor, or walls of the unit, so ensure you check these areas also.
What should I do to solve the issue?
All of our units run an automatic defrost in their running cycle, however, these automatic defrosts are stopped when doors are opened. If interrupted the efficiency of the automatic defrosts are significantly reduced. This re-concurrence of interruptions over a period of time will eventually render the automatic defrost less efficient. Our units additionally come with manual defrost or tempering cycles which are able to be activated in order to remove this ice-build up.
If any ice is detected then you need to run additional manual defrost or tempering cycles.
Ensure that after the cycle all ice has melted, and the water has completely cleared from the drains. Depending on the amount of ice build-up, it may be necessary to run more than one additional manual defrost or temper for longer in order to clear all the ice and ensure all water has drained away. For very excessive ice, empty the unit and run at at least 8oc and ensure all water drains away. If all ice and water hasn’t cleared then by running the unit again you are more likely to rebuild ice up again quicker.
We recommend that clients get to know their units, understanding when automatic defrost are run and how long they run for. Keeping a chart on the wall can lend a hand to ensuring that during automatic defrosts the doors aren’t opened. We would also recommend that units are cleared out and a full manual defrosts run once a month.