I have now given up on keeping the water from freezing. I take out fresh water 3-4 times a day now. The heated base works great with the 3 gallon galvanized aluminum water font. It is currently -27°F outside, and only 8°F in the coop. The water in the font is not frozen. The birds are all doing fine.
Here's what we've had so far:
...and keep in mind, our summer was a cool one this year... only got over 65°F 3-4 times this summer, and then it cooled off slowly so my birds acclimated well over the span of about 8 weeks. There are about 25 full grown birds in the coop, and about 9 that are just under 12 weeks old. The coop is 8x8', and the ceiling slopes from 7' to 5' in the back. 2" R-19 foam-board insulation between 3/8" plywood. Deep litter. One window that swings up, doesn't seal shut. Two pop-doors, one on adjoining walls, covered with towels to cut the drafts.
~ At
0°F all birds stayed outside all day unless they were laying eggs.
~ At
-10°F I still had birds that chose to sleep outside, but there was more in/out traffic to the coop.
~ At
-15°F, birds were a little more hesitant to stay outside. But they would go out and scratch, then go back into the coop to warm up.
~ At
-25°F/-31°C, only a few of the biggest birds ventured outside for brief periods of time. But for the most part, all birds stayed in the coop.
The only exception to this is that my chukar partridge are outside 100% of the time (it is a treat for them to find a way into the coop), and they have a hay-lined thick wooden box to huddle in located in a sheltered corner of the run. They seem to prefer being outside, and I see them running around the run at all temps so far.
My biggest challenge right now is keeping eggs from freezing.
We have not had a lot of wind lately, like Kodiak has, so these are not including any windchill factors (even though they aren't AS affected by windchills). The birds do tend to stay indoors more on the really windy days, just because it gets under their feathers. The only birds that I've really had to keep an eye on for frostbite are my single-combed Dorkings. Even in the breeder coop, which is completely draft-free, just cold, the tips of their combs are having issues. But that has only been when the coop has gotten down below about 14°F inside.
I have 5 of the almost-12 week old babies inside right now, because I noticed that they were showing signs of distress. One was pushed outside and got chilled, so I brought them into the garage which is heated to about 60°F. If you have young birds, very old birds, or very few birds, just watch them carefully for signs of distress. You'll know when it's time to add heat.
