One of my pet peeves is seeing heat sources inside of the house when
I'm running the AC. The three that get most of my ire are the
laundry room, the dishwasher, and my over stove microwave/vent (that
just filters the air and returns it to the room). I realize that I
could re-route the microwave/vent to the outside and add blower/vents
to the small second story laundry room and behind the dishwasher to
minimize my ire, however I always wonder if by doing this my total
energy costs might rise because I will essentially be knocking three
holes into exterior walls and replacing R-19 insulation with a
flapper door whose R value is probably .000000000001, and will allow
the cold to enter all winter 24/7.
Is there a solution to my dilemma?

Ven the room itself; get one of those thermostats with
hygrometer/thermometer settings. If you have winter weather, the heat &
moisture's useful, not so in the summer or warm climes. Heck, or even
do it manually with a vent & just a timer; that's what we did.
I'm cheap & those controls are expensiveg.