I saw a very cool article on "If it's hip, it's here" which covered an award winning Dutch design company's new product, a passive refrigeration system and a modern take on the age-old root-cellar concept.
They're not unlike the pre-made storm-shelters that have become quite popular in tornado and hurricane prone areas in the US, and even the tsunami pods that came to world attention following the 2011 Tohoku earthquakes. These are a far more sedate creation, with a far more pastoral aspect of food and produce storage. This is the Weltevree Groundfridge.
It is an ingenious way to provide an affordable, insulating, cooling and storage system for wine, fruit, vegetables and cheese. It is a modern, pre-fabricated root-cellar which can hold as much as 20 standard refrigerators, without the use of electricity and uses the insulating effects of the soil and water to keep the internal temperatures at between 10 and 12oC (50° and 53°F) throughout the year. This airtight, water-tight, vermin-resistant and ventilated system (the ventilation system supplied can be operated remotely using an app) which also monitors the temperature and humidity within the Groundfridge. Being a small design company, their products are mostly small-production oriented with the polyester shell being hand-laminated and are fitted-out with a wooden handrail and shelving. Other options they offer include LED strip lighting and built-in cabinetry.
The Dutch based Weltevree will transport and deliver the Groundfridge locally, dig it in and cover it up with the very soil taken from its new lodging place. This covering layer of soil ends up being about 1 meter thick and has ample insulating properties for a steady core temperature within the Groundfridge as subterranean water provides additional cooling. Depending on where you live, there may be an added benefit: installing the Groundfridge may require no permit, and when digging it in, because all the excavated soil then becomes the covering, no soil need be carried off of the premises.
The Groundfridge has a storage capacity of 3,000L and will store around 500kg (or 1,102lbs) of food (Weltevree suggests the harvest of a 250 m2 vegetable garden). That’s enough to prepare 350 meals for a family of 5. its main diameter is 228 cm, (7'5") and weighs 300 kg (660lbs). So it is a significant piece of construction.
On average, 20 A grade EPC (Energy Performance Certificate) Refrigerators combined, use 6,620kWh per year, whereas the Groundfridge performs the same feat completely without any electricity. The autonomously functioning underground root cellar with a constant temperature of around 10oC. You'd need to be sure about your local water-table, including seasonal variations, because it would be terrible if it broke free due to raising water-tables, and some areas might have different subsurface temperatures.
That said, this looks like a really cool idea, and I'd love to have one myself.
