A closed loop refrigeration system using a gas hydrate having a temperature below 0° C. has: a first circulation loop extending through a gas hydrate formation device 1, an object 2 to be cooled and a separator 3 and back to the formation device 1 and including a gas hydrate line 10 for transporting a gas hydrate having a temperature below 0° C.; and a second circulation loop for gas extending through the formation device 1, a compressor 4, a cooler 5 and a decompressor 6 and back to the formation device 1, wherein an object to be transported in the first circulation loop is transported together with a liquid carrier.

A leakage sensor for a heating unit of an absorption cooling device for a recreational vehicle, a heating unit, an absorption cooling device, a vehicle and a method for operating an absorption cooling device are provided. The leakage sensor uses sensor pins to detect cooling fluid leaking from the boiler of the heating unit of the absorption cooling device into the boiler insulation by measuring the electrical resistance and/or conductivity within the boiler insulation.

A closed loop refrigeration system using a gas hydrate having a temperature below 0 C. has: a first circulation loop extending through a gas hydrate formation device 1, an object 2 to be cooled and a separator 3 and back to the formation device 1 and including a gas hydrate line 10 for transporting a gas hydrate having a temperature below 0 C.; and a second circulation loop for gas extending through the formation device 1, a compressor 4, a cooler 5 and a decompressor 6 and back to the formation device 1, wherein an object to be transported in the first circulation loop is transported together with a liquid carrier.