I used clamps to hold to plexiglass to the frame of the model and used fog to represent the air moving through the house and the vent system.
I used paper as the vents because paper was one of the only materials that my servo could hold up.
I used a heated pad (one that is often used for headaches) to heat up the air but microwaving it and putting in at the bottom of the model.
I used a garbage bag to trap the fog and then put the opening of the bag into the upper vent to push the air into the house.
I used plexiglass as the front of the model so that I was able to see the fog and the way the air was moving. This is a video of the glass being cut.