Similar to a refrigerator, an transfers thermal energy from inside a room to the outdoors
a. vacuum
b. air conditioner
c. dish washer
d. water heater

Refrigerators and air conditioners operate on the same principles,
and use largely the same inside guts.  The difference is that the
refrigerator takes heat away from the the stuff inside and dumps it
into the kitchen, whereas the air conditioner takes heat out of the
kitchen and dumps it outside the house.