Hi Robert,
Yes I have considered a cooler like Asi's, until I heard about the peltier type, now I am not too shaw which way to go. With the cat cooler you have to be carefull that you are not blowing moist air into the tube. The Peltier appeals to me because it is not doing that but just cooling the trapped internal air. I would like to know how efficient a peltier would be if it was mounted on the casting behind the mirror externally. Or would a cat cooler be far quicker and blowing moist air isn't an issue.
If someone can answer these questions I will be very grateful.