Purchased this to hopefully take some of the heat out of an otherwise unusable conservatory and although it is somewhat a bit of a pig to put on, after waiting for some warm days to arrive I was pleasantly surprised at how effective it is, I would say it has cut out at least 70% of the heat which makes the room now use able, the added bonus is the privacy factor in the day time it is almost impossible to see in from the outside whilst a clear view is had from within, very impressed with this, just give yourself plenty of time to install and have plenty of patience and a good craft knife