Actually it would help to have a vent in the opposite side that has the opening now so air can pass thru. Just so the openings are above the roost so the wind blows over them and not on them. Here it explains it...
Water inside the coop is a bad idea. Need plenty of ventilation also to let the moisture out. Wood chips on the floor soak up a lot of the moisture. Raking it over every few days help.
I put a 40 watt energy saver bulb with a reflector out in the run. It is set to come on at 430 am and goes off at 730 am. They see the light from the coop and come outside. Had the light going about 10 days now and egg production has increased from 2-3 a day to 8-10 a day. So far they haven't...
I wouldn't even consider using a heat lamp due to the fire risk. Even a 75 watt bulb may get to hot if it is close to anything. As long as the wind does not blow thru you will be fine. Still need some open vents.
I'm thinking they have survived thousands of years without ac....maybe just good ventilation and some shade will be sufficient. Don't spoil them to much...they may want cable next...lol.
I put the nipples in a plastic pipe one foot apart and ran it along the fence sloping it down so they are at different levels. So far my 11 hens have shown no interest either. Of course I just took them in from a friend that has been using a pan for 2 years. Haven't gave up yet but I'm thinking...