I have been amazed at the difference in temperature between the outside and the inside. For several weeks, I only had a space heater. The temperature in my office never got below 58 degrees, even though the outside temperature was in the mid 30s. Now, that the weather has moderated, I rarely use my mini-split.
I must admit that I was a little concerned that such a thin product would be as effective as it is. I am very pleased!!