Pre-cooling and packing a fridge to save power

Most of the saving comes before you leave the driveway. A fridge that starts cold, full and well packed has an easier job.

Pre-cool the night before

• Do it on mains power at home. ARB recommends pre-cooling the unit along with your food and drinks the night before¹.
  • Bring it inside, power it on, set the temperature you want, and leave it overnight¹.
• What you gain. ARB lists less DC power use, no waiting for items to cool, and fewer lid openings as a result¹.
• Pre-chill the contents too. ARB says pre-cooling removes the wait for items to cool¹. Less waiting means fewer lid openings.

Fill it up

• Full beats half-empty. ARB's tip is to keep the fridge as full as you can¹. Dometic's version is to keep the cooler fully packed².
• Fill the gaps. As you take an item out, ARB suggests filling the space with another drink¹.
• But leave air paths. The South Australian Government's advice for home fridges is to leave room around items so cold air can circulate³. Don't wedge things in so tight that cold can't move.

Pack in the order you'll need things

• Reverse order. ARB's rule is to pack items in the reverse order you'll eat them, to cut how long and how often the lid is open¹.
  • Dinner for day three goes in first.
  • Tonight's dinner goes on top.
• Colder things low. Keep items that need to be colder at the bottom¹.
• Drinks. ARB says to choose canned drinks over bottles¹. The same page says cans cool down faster and make better use of space.
• Group things. Put snacks and drinks for the day in one easy spot, so one opening gets everything.

Open the lid less

• Dometic's rule. Keep the lid closed as much as possible².
• Plan the trip to the fridge. Think about what you need before you open it, so you can get everything in one go⁴.

Set the temperature for the situation

• On the road. ARB suggests a lower setting while driving, then a more economical setting when the engine is off¹.
• At camp. Pick the warmest setting that still keeps your food as cold as you need.

If power cuts out

A packed fridge buys you time. In Dometic's lab test, 24 soda cans in a CFX3 55 warmed at roughly 1.8°C an hour with no power². The inside was 3.3°C and the air 21°C in that test². Other conditions will give other results, so treat it as a guide to the idea, not a promise for your fridge.

A one-page packing checklist

• The night before: plug in at home, set the temperature, load chilled food and drinks.
• Pack the last-needed items first.
• Fill gaps with drinks, but keep a little space for air.
• Cans over bottles where you can.
• One person opens it, once, with a list.
• Lower setting on the road, a more economical one at camp.

Cooling the load is only part of the picture. The ventilation page covers getting heat out, and why use changes explains the rest.