The more I read, the more I am told NOT to heat a chicken coop, but ...
Only when the amount of chickens and the size of the coop is appropriate.
Apparently, each chicken gives off a certain amount of heat,
AND they are naturally capable of keeping themselves warm.
Too small and they are crowded,
too big and not enough heat generated by the chickens.
The perches need to be above the top of the door,
so the chickens roost inside the warm area of the coop at night.
The perches also need to be flat and wide rather then round.
Their feet will then sit flat on top of the perch and they will hunker down,
to keep their feet warm.
All of the above, gleaned *from the net*, and those that *made sense*.
I have a triangular shaped coop (easiest to make) so the heat concentrates on the top end.
About 6 inches down from the top end, there is a remote sensor to my
weather station which tells me the temp and the humidity of the coop.
Surprisingly, it has always been warmer in there, than the ambient temperature !!
The humidity is always, for some reason, really low, so it is dry in there.
I do have, in the top of the coop six *2 inch diameter* vent holes,
three on each opposite side of the coop.
There IS an infra red heat lamp in the coop, which is plugged into a *ThermoCube*.
This cube turns on at 35F and shuts of at 45F.
http://www.amazon.com/Farm-Innovato...TF8&qid=1412872030&sr=8-1&keywords=thermocube
Never has gone *on* yet ... (This is my first *year* with chickens)
We will see if this continues when the cold weather sets in.