  In the past decade several theoretical Maxwell's demon models have been
proposed exhibiting effects such as refrigerating, doing work at the cost of
information, and some experiments have been done to realise these effects. Here
we propose a model with a two level demon, information represented by a
sequence of bits, and two heat reservoirs. Which reservoir the demon interact
with depends on the bit. If information is pure, one reservoir will be
refrigerated, on the other hand, information can be erased if temperature
difference is large. Genuine examples of such a system are discussed.
