You just gave me the best analogy for open topped enclosures EVER!Same as a house is not air tight.
An open topped enclosure is like taking the roof off of your house. You can run the heater all night in January in your house, but where does the heat go if there is no ceiling? Likewise with the AC in August. So many comparisons. The lights are inside our houses. How well would our lights work if our houses had open or screen tops and all the lights and heaters were outside the house? Your air movement comparison is spot on too. Our houses are closed chambers! We open the windows if its hot inside and cooler outside. We close the windows if its cold outside and warm inside. Ventilation!
Brilliant Barb. You've just made the closed chamber thing easier to explain and easier to understand. Thank you.