Hints

Run coolroom so it gets to its desired temperature.
Then load as much stock as possible and try to keep door closed for as long as possible.
Remember that every time you open the door to enter the coolroom, a lot of cold air will rush past you and straight out the door.
Make sure you are quick to enter and exit the coolroom.
Do not leave the door open.
Try to park the coolroom in the shade where possible.
Store cartons/boxes off the walls with gaps between them for air circulation.