Because heat rises. Ergo, if they were located by the ceiling, it wouldn't warm the whole room efficiently.
the middle vents only supply air from the ac unit using a separate in dash fan. the floor and defrost vents come only from the heater
No, floor vents will not help in cooling your house since they are only used when your air conditioner is on. Fans are the cheapest way to cool a home down.
I believe the upper vents are for A/C only. The floor vents are for the Hot air. Test your ceiling controls by moving the knob from cold to hot, you should hear the air pass from upper vents to lower vents. Providing of course you have selected REAR from the front control panel.
thermal vents
Yes vents can be in the floor instead of the wall.
Cold air return vents are the ones on the wall
Heating vents should be located near the floor since hot air rises. If the heating vents are located near the ceiling the heat would stay there and not warm the room.
thermal vents
the vents work because of the heat which can make the hot air balloon go up
the vents work because of the heat which can make the hot air balloon go up
This is due tobuoyancy. Think about a hot air balloon as an example. Warm air has greater buoyancy than cooler air and will rise. Conversely, cold air will sink when introduced to a warmer atmosphere and this is why you see cooling vents placed in the ceiling.
To properly vent a garage for air circulation and ventilation, install vents near the ceiling to allow hot air to escape, and vents near the floor to bring in fresh air. Consider using a combination of passive vents and mechanical fans for optimal airflow. Regularly clean and maintain vents to ensure they are functioning properly.