After testing these walls in my yard for a sunny day I can tell you that the sun will penetrate thru the thin walls somewhat. sitting right next to the wall I got pretty warm from the sun. And the wall got rather warm. I had to move my chair away from it about 18inches. This in 80 degree weather with sun and clouds. It will billow to some extent which I have to think is by design. The elastic sewn to the hooks for stretch. I tried not to make it too tight when I put the wall up. This would just lead to a failure with a strong gust. So to sum up they are good for some privacy, although the sun could put you in a position where someone outside could see your silouette. They keep out some sun and do provide shade. They will warm up the room and in cold environment would probably hold some warmth. They take down easy and I just put up one wall to increase the shade but leave the other sides open for breezes. Forget about keeping bugs out. More of a day shelter.