As summertime approaches, you’ll begin to see these dear old friends pop into car windshields. Maybe you faithfully keep one in your own car?
At BNG, we’re encouraging you to take notice of these this summer, and be reminded of how the same concept applies to your home comfort! Here’s how they work:
When your car is parked in the summertime, the un-shaded windshield allows sunlight to filter into your car and create a greenhouse effect (this makes the temperature inside your car even higher than the temperature outside of it—the reason why we dread getting back into our parked cars in the summer!).
It seems simple: the windshield shade is there to block the rays from getting into your car! Well, it IS a little more complicated than that! The reflective surface that trademark the shades actually bounce the light back outside of the car, reducing the car’s interior temperature. This phenomenon is achieved because the light trying to come into the car is actually different than the light that gets bounced out of the car!
The light that we’re talking about is infrared light, which is really, really good at heating air. It’s composed of different wavelengths—some visible and some invisible—and the foil on your windshield shade keeps out the visible light by bouncing it back out of the car! Because of that bounce, less of that heat gets trapped inside your car.
We can apply this same concept when it comes to your home. Insulation keeps heat out of your house in a similar, but different, way. For example: If your home were not properly insulated, you could try covering it with foil or painting it white so as to bounce visible infrared heat off of it. If your home is properly insulated, the bounce-back happens on the outside of your home, ensuring that the heat of the sun is blocked from entering the air conditioned space of your home! On the inside, the dense properties of your insulation also ensures that the clean, cool air produced by your HVAC system is not released back outside of your home. Find a diagram of that process below.
So, next time you see a car protecting its interior from the heat with an aluminum shade, take a moment to consider if your home is properly protected!