ventilation problem

I have a new coop its insulated walls and ceiling,its 16x16 and I have 30 chickens in there.I have two small vents on the south side and one on the north side up next to the ceiling.I do have two big windows that slide open and two doors.I close it up at night because its really cold here now(northern maine).The vents stay open all the time.The amonia smell and the humidity are high in the morning when I go in and I worry about them breathing that and I know the humidity is to high,what can I do for more ventilation without loosing to much heat?Do I need to put small vents on the east and west side to?The vents are 4x12

Wow that's a lot of humidity for a well ventilated coop of that size. Is their waterer adding to the humidity? Sounds like you have enough ventilation for winter. Maybe keep their water out in the run area, course then it freezes unless you have one of those fancy ones that heat the water enough to keep some of it liquid. Good luck!

Open the windows a little
They can stand the cold better than the ammonia

I`m going to say no on the water.Its one of those three gallon plastic one and I do have it sitting on a box with a light bulb in it so it won`t freeze but have not had to use it yet as it stays above freezing in there so far,I`ll see next week its supose to go down to 4 degrees next friday night.I could take out the waterer for a night and see if that makes a differance.

I thought about opening up the windows a little bit but one of the roosts is by the window,I`ll try opening up the one furtherest away from there roost.I am using the deep litter method maby I need more shavings,there is about 8 inches on the floor now and I also mix sweet pdz in with it that is supose to curb the amonia smell.

Three things can contribute to moisture in the coop aside from leaks. Those are urine, poop, and breathing. Likely your vents are too small for the number of birds in there. Coop is very large so size is not an issue. I have 24 in a coop that is 8 x 16 and I closed all 4 windows tight last two nights. Had a little frost on E window, but other than that, no issues. My coop has ventilation as follows:

Two gable-end vents that are 12" X 12" ea.

One 18" turbine vent in center of roof area.

Two continuous soffit vents that are 18 ft long each X one inch wide, screened.

So the upper regions of my coop breathe constantly no matter if all four windows closed or not. All of my permanent ventilation is at a level of from 8' to 10 ft above the floor. The 4 large windows open fully for variations in degree of ventilation. I do clean poop planks daily and have windows open for at least two hrs. I do not heat tho, being in E Tenn. I have no insulation.

I would put your heat on a timer so that it is on only overnight. Open windows in AM when you clean coop. If you have poop planks, scrape them clean daily. If not, turn litter to cover poop daily. It is a constant source of both water vapor and airborne toxins. Close windows in late morning or anytime in afternoon . Complete air changeout is a vital daily chore, as important as food and water. For severe and lasting conditions, you may need to modify that schedule.

I forgot to say that if all else fails, you can buy a product called stall-dry that will absorb moisture and odors. But modification of the ventilation system is the only permanent cure.

Yes, I would say add ventilation up high. That's not many vent openings for that many chickens...it really equates to just one 12" x 12" opening for 30 birds. When you say it like that, I think you can see how little that is... Too many vents- you can always cover them over w/plastic or cardboard. Too few vents - not a lot you can do except add more ventilation... If the windows are at roost level, I would try to open them as a last resort, unless you can nail a board or something in such a way as to divert the air from hitting the roosting chickens... I don't do deep litter, but I love the stall dry stuff!!

I agree with what the others said about ventilation. If in doubt, add more!
What is their dropping board situation? If you can collect all the poo everyday and get rid of it, would help a lot. I use a dropping board with sides and a layer of Stall Dry on it. Love it! I clean it out with a kitty litter scoop and it never smells.

I'm afraid that if you don't get some more ventilation added, you are not only going to have ammonia build-up to deal with (which isn't good at all for breathing), but you're probably going to have frostbite problems too. Gsims's is right - air exchange is important. Cutting more ventilation up high is preferable, but if it's not possible, then you really should consider poo-boards and opening everything up in the morning. I'm more likely to recommend more ventilation as opening up the coop to air it out won't be so great when it's 0F outside and you're working hard to keep the coop warm. I think Pat recommends 1 sq/ft of ventilation per chicken. Now, with 30 birds, that might be overkill, but you get the idea.

Good luck! Stay warm!