Some background info:

My house has a couple of bedrooms with one vent. Mine has two. It means I get extra/too-much heat and A/C at times. 

The situation:

My dad walked in a few days ago and told me that I should cover one of my vents, because I had the window open for an hour to air out my room (nasty smell, probably from a shower and humidity) and he thought I was doing it because I was hot. I explicitly told him no, I won't do that. It's a bad idea (even if you don't include the fire risk) to cover it with cardboard, because it causes a reverse flow and damages the system in the long run by forcing it to work harder, and it would still result in the same amount of heat being redirected to one vent (best case scenario two-three of other rooms, but not with the way our house is laid out). I've called numerous AC/Heater repairmen, and asked them about this, because I wanted to do it way back. Almost every single one of them told me it was a bad idea. That, added with the bonus of me looking it up myself, dissuaded me from that idea. 

I came home the other day, and saw that, in fact, my dad had ignored my wishes, which was normal at this point in time, and did it anyway. I do live with him, and I am aware that he owns the house. That being said, I would assume that any rational human being would want to avoid being roasted alive by their own A/C system, so I took it down and reverted to my previous solution: just wearing more or less clothes based on how hot/cold I am when I go to sleep. Walking around in shorts and a T-shirt isn't bad at all, either. 

He walked in today and exploded at me, for defying his authority and taking down a piece of cardboard held up by masking tape. I told him I slept in that room and I should have some opinion, but he said it was his house. I told him I would just sleep on the couch and he told me I could sleep on the street for all he cares. He then went and got a ladder and put it back up, telling me that I would see what would happen if I took it down again.

Everyone on his side of the family (grandparents) agree with him, think that I shouldn't "defy my father" and call me a problem child for even arguing with him at all. They basically told me that if I didn't like what my dad was doing, I could move out with no support from anyone. My sisters think the man is crazy. I personally want to move out soon, but not before actually being able to.

AITA?