The first broom head is a regular broom head and cloth the second one is one that I have recovered and I have a hole in the middle of it to let it breathe, the third one is one that I have recoverd like the second one but I have placed a piece of tin foil between the fabric and the foam.
So I took a lazer temp gun to see what I could prove. In rubbing my hand over each one at the same speed to create friction to a count of 10 and taking a reading. The first one was 94 F the second one was 92 F and the third was 91 F.
Now this is where my theory comes in. The first broom head is made of cotton and it does create friction and we know this because it gets wet from sweeping and it takes moisture out of the ice.
The third one with the foil does not let the warmth from my hand into the foam so it stays one degree colder than the second broom head.
The second one is one degree warmer (92 F) than the third broom head, but I was creating warmth with my hand. These broom heads are used on "ice" and it is a negitive temperature, and when sweeping you are moving down the ice so it is next to impossible to create heat. What you want to do is keep your broom head cold to be more effective. I do not believe that the tin foil works because it is not letting the cold from the ice go into the foam. That it is more to do with the fabric used and putting a hole in the plastic to keep the broom head cold, and the benifits from sweeping are increased for you and your team.