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Riegel_Haribo t1_j28i2c1 wrote

Reply to comment by Kopites_Roar in Liebherr announces worlds first refrigerator that uses a vacuum in conjunction with finely ground and sustainable lava stone, to insulate its appliances. For the very first time, it is possible to produce freezers with the energy efficiency class “A” in accordance with EU while offering 25% space by rosesandtherest

The first refrigerators are only getting this in the door.

What typically degrades vacuum is outgassing. They've ground up some rocks (and claim that prior insulation is petroleum foam instead of fiberglass which is also environmental), but if not an engineered material, it may have volatiles that continue to be released.

Vacuum can be renewed, but pulling quality vacuum takes time (after a certain point, you are waiting for molecules to wander out of the vacuum port) and dewar-quality needs multi-stage pumping with consumables like pure oil and liquid nitrogen.

The rock/pumice, etc is likely a material to prevent the layers from collapsing onto themselves from pressure. However, that is also what is called a thermal short.

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