Doggy door- what kind is the best?

Question

We have an old grainery that we need to install a doggy door on or something similar to keep the cold out in the winter time. Last year we used a swinging piece of plywood and it worked, but didn't seal well. Any suggestions on what is a good door to keep the blowing cold wind out? We heat the area for the dogs but want them to be able to go in/out to their kennel on their own.

Answer 1

http://www.thepetdoorstore.com/html/kenn...

It says that these are kennel pet doors.....I don't know if you wanted to buy one.  It will probably work the best.