Devices and methods for compressing thermal insulation material into blocks of insulation are disclosed which include a support surface for the compressed blocks of insulation, a compression device with a compression surface, and a feeding device for feeding thermal insulation material. By adapting the compression device for reciprocal movement between a first position, wherein the feeding device is allowed to feed thermal insulation material to a position on the support surface, and a second position, wherein, during movement from the first position to the second position of the compression device, thermal insulation material fed by the feeding device is compressed, highly compressed blocks of thermal insulation material are obtained that are suitable for use with known shredding devices.