So the last experiment was disappointing, because it appeared that plastic did very little to prevent heat loss for your leaky hallway window. Things aren’t looking so good for the thin plastic as insulation.
Luckily, we have another scenario. Plastic over part of a window has come “undone” giving us the perfect side by side comparison of surface temperatures over a window with and without plastic – without interfering sunshine and the heat from solar convection.

This question is important to many homeowners and renters because we believe that placing plastic over our windows will halep us save energy on cold winter days and nights. Some plastic makers claim that plastic adds at least 1R value to the window.
I doubt this to be true. But using the information presented in the home energy audit kit, we can easily see heat loss with and without the plastic to see how much of a difference it makes.