I'm also thinking space heater because it's not in a window or otherwise connected to the outside. That, and cats seem to like being warm, hence hanging out by the heater.
We could replace the air conditioner tag with fan and not have to worry about it.
Eh, a fan is too distinctive from this. Do air conditioner and heater share the same tag? they look enough alike that people really couldn't tell them apart without character clues, such as sweating and looking hot. We could just have them both share a tag, and let god sort them out.
Tagging without outside information can be hard, especially since many wall mounted climate control units in Japanese households can be run as heaters or coolers as the need arises.
In cases like the above where the unit is on the floor, it's almost definitely a heater since it has no connection to an outdoor condenser.
