My in laws just brought us a heater for our coop! How very kind of them! It's a radiator heater with a dial from 0-8. We are planning on raising the roost(12 inch shelf) and placing it underneath the roost for the winter. Next to the radiator will be the waterer. We are planning on keeping the heat on the lowest setting to keep the water from freezing. Our coop size is 12x4x8 for our 8 chickens. We are also covering the sides of the run with plastic, so they will have access all winter long(our run has a steel corrugated roof). Hopefully the sun will heat up the plastic to keep it a little warmer. I'm debating whether or not to cover the run floor with hay or part. Right now it's full of construction sand, which is very easy to clean. Our temps get as low as -21F actual temps. What do you think about the heater? Should I throw hay in the run? The coop will have wood chips inside.