What Happens In Summer & Winter?
During winter there's an immediate reduction in radiant heat loss to the cold window glass, and people feel warmer. Here's how it works:
All objects (including people) give off and receive radiant heat. When people give off significantly more radiant heat to cold glass than they get back, it can feel like a chilly draft, even if the window is tightly sealed. When the shades are lowered, your comfort level is increased. When people lose enough radiant heat to feel uncomfortable, they will typically turn up the thermostat, which consumes energy resources and adds utility costs. But when a well-insulating shade minimises radiant heat loss, people can often turn the thermostat down, saving both energy and money.
Similarly in Summer time the reverse effect is seen. The honeycomb shape that creates pockets of air trapping heat in the wintertime traps heat in the cells keeping it cooler reducing the warmth inside. It's like the difference between being in direct sunlight and under a shade tree.