U.S. patent application 20160109186 (applicant Thermo King Corp., Bloomington, Minn.):
"An apparatus for the storage, transport and distribution of refrigerated or frozen goods, in particular for thermally insulated containers of refrigerated vehicles, cold rooms and the like, including one or more thermal storage devices, each including a housing defining a cavity for holding a phase change material. The cavity contains a heat exchanger that may be supplied with a heat exchange fluid. The housing includes a substantially flat wall portion and a heat transfer enhanced wall portion. The apparatus includes ventilator in communication with the thermal storage device."