  In this paper, we study the quantum self-contained refrigerator [N. Linden,
S. Popescu and P. Skrzypczyk, Phys. Rev. Lett. \textbf{105}, 130401 (2010)] in
the strong internal coupling regime with engineered reservoirs. We find that if
some modes of the three thermal reservoirs can be properly filtered out, the
efficiency and the working domain of the refrigerator can be improved in
contrast to the those in the weak internal coupling regime, which indicates one
advantage of the strong internal coupling. In addition, we find that the
background natural vacuum reservoir could cause the filtered refrigerator to
stop working and the background natural thermal reservoir could greatly reduce
the cooling efficiency.
