Freezer

After an embarrassing Duh! moment when we realized that the eye-wateringly expensive fridge did not even have a freezer compartment, the challenge was on to find a way to add that most critical of appliances !

However, at this close-to-finish stage of the build, there was no room left for an additional big appliance. So it was time to scrap the whole van and start over from scratch... 😥

Until I stumbled on this $730 Vitrifrigo 20 liter 12V drawer freezer:

At about 17.5" Depth / Width and 9.8" Height it happened to barely fit in the pantry's bottom drawer's space !

So a cradle was built, that slides into the drawer space:

Quick release wheel hub bolts, pictured above, were repurposed to secure the cradle in the cabinet, and provide a toolless quick install / removal. They screw into 1/2" aluminum plates that were drilled & M5 tapped:

The freezer came with nut inserts on its sides, so machine screws simply hold it in the cradle:

The grey insulation foam pads in the pic above were added after the first few days of use showed that the unit was cycling suspiciously often. Indicative of poor performance.

Since the back of the unit generates a lot of heat, and as the pantry cabinet is poorly ventilated, the insulation pads help cut down the thermal coupling from the hot compressor and condenser to the cool plate.

Conversely, to increase thermal coupling between the cold plate and the food, large holes were drilled in the back of the drawer. This improves cold air convection:

After these mods, cycling seemed to come down a bit, and the temperature seemed to more consistently settle close to -11°C (12°F), rather than the previous -6°C (21°F) to -11°C range.

Not fully satisfied yet, though. Less cycling at night = a better sleep !

So a closed-cell foam pad will be added in the front of the drawer, as its face provides very little insulation under the latch. Also, when either the fridge or freezer turns on, the other follows soon after. Seems indicative of high heat coupling between the 2 units. So an intake vent and a push-in fan, working in a push-pull configuration with the pantry exhaust fan, will be added at the bottom of the pantry to evacuate heat better.

To avoid pinching the 12V power and Freezer-Fan-ON cables when inserting the unit, a bungee cord was attached to the back of the unit and to the pantry's back wall. The cables now remain suspended the whole way, clear from interference:

The Freezer-Fan-ON signal was just tapped from the freezer's fan cable, and is OR'd with the Fridge-Fan-ON signal via diodes to create the Pantry-Fan-ON signal. See the electric board circled in red in the pic. The Pantry-Fan-ON signal then powers the pantry exhaust fan mounted on the pantry's side (upper right corner in the pic) when either appliance is on: