It was a long winter and here it is August again, and I am reviewing what I did last year, what worked and what didn't. Am so glad this thread has continued as so much of the help shared here has been so useful.
In a nutshell, the winter here was colder (extended periods of subzero temps) than years in the past - with only moderate snow - and the wind was sometime ferocious. The small open end hoop structures, with huge deck boxes for overnight shelter, we're just barely adequate, but much better than nothing. The cinder block heated 5 gallon water buckets worked well, but for all the work they were to set up, my birds much preferred to eat snow. The bucket feeders with 3" elbows worked fine for the chickens - and for all the mice, too. (I can fix that)
The tarp and 1/2" electrical PVC held up fine, even with heavy birds hopping around on them. Two major problems with these, however: 1) they were only 4' feet high, and my back will never forgive me all the bending over I had to do to fill all the feed and water buckets, and 2) because they were open ended, (I think), the chickens were over exposed on really cold days and got bad frostbite on their (rooster) combs. The enclosures they sheltered in overnight were too small to be cooped up in, and I believe they were frost bitten while out running around in the cold during the day. Also, I often cracked the lid open a bit, and melting snow may have dampened their housing a bit.
So this summer I am working on larger (10 x 12 x 7' high) hoop coops that are both enclosed and a snap to construct. They will be big enough to house the overnight huddle boxes, and also to have some decent roost space. Many of last year's woes will be solved with these.
Here is my question, (and it's very possible it may already have been asked and answered in this thread): I have never been a fan for heating coops in the winter - I know birds can be VERY hardy to cold - but I am returning to the idea of using gravity feed water drinkers. I've used large heated rain barrels to good effect, and I've used the light bulb heated horizontal nipple 5 gal water buckets with no problems, but now I'm thinking it would be better to heat the coops just enough to keep the water from freezing. Am thinking to use a Thermocube with a wall panel radiant heater. Gravity feed drinkers will freeze solid in subzero temps, no matter how much I insulate them. So, given the high potential for subzero temps in winter, what wattages might I need to keep my drinkers above freezing? Given a cubic foot space of around 700 to 1200? Taking into account a chicken population of 10 - 15?
I think the panels might be safer than the cinder blocks, especially if I build protection from the chickens around them (hardware cloth?). What do those of you who've had experience with these panels have to say? Is 400 watts OK, or should I get a 600 watt panel for something this size and temperature?
Many thanks to all of you who help out on this thread. Laurie in Berthoud