For those not considering the Texas fan optionů..
There normally is a 120v outlet in the back of the refer compartment, there was one in my 19' and I looked today and there is one in the rear of the 21' refer compartment.
Very easy to access to install a small 12v fan with a small ac/dc black brick,plenty of room and all you have to do is remove the refer vent for access. Something to think about if you ever felt the need to improve the hot air circulation.
never in doubt, often wrong