I took a real large wooden crate and cut it down to 44 x 42 x 30. It has a wood lid and is solid all around. Nights here are still in the low 30's. Got some chicks coming in about the 24th. I have a red 250w heat lamp in there. Should I install screen in the top for fresh air? The top seals with 1/4" gaps in areas. Bottom has some 1/32 or smaller cracks between boards. What is the overall opinion on drafts and fresh air? It would be easy to put screen in the top to open during the day and close at night, or just prop the lid open some, but I worry about things getting too hot. I was going to put the heat lamp towards one corner to allow alot of area to spread out just for that reason. Only gonna have about 25 or so chicks in there at a time. This is my first time, so I want to to try to do things right.
Sounds to me like it would get way too hot with a lid on. Just hang the light over the brooder open. Sometimes I put a bit of tin foil over one end of my brooders so there is a warmer side. You have time so try it out and see how the temperature is. With the big heat lamps you have to be very careful of fire. They do get really hot and there have been many fires lit by those lamps. The other problem with them is that being one heat source if they fail the chicks have nothing. Personally I always use regular bulbs now, and a few of them so that if one burns out the chicks still have others. I learned this the hard way, lost a whole batch. With the regular bulbs you can cover the area partially with tin foil and they do great. Again set it up ahead of time and see how it copes with your temps. Drafts that hurt the chicks are the cold air running over the bedding so if all your walls are solid don't worry and ventilation is manditory.
I agree with adopted...I'd make a cover with wire rather than using a solid cover if you are worried about them jumping out, and then hang your heat lamp. Putting a 250 wt lamp in there with it no taller than that and I think your chicks risk getting too hot and not being able to escape, especially with a solid lid top. Plus as they grow you will need to be able to raise the lamp each week to reduce the temp 5 degrees each week until it's down to 70 by week 4-5.
I have my top with wire cloth, and use a big pc of cardboard that I can slide around and adjust the amount of coverage. Seems to work really good. You can do a search of my posts and see the pics. I used a shipping crate that I cut down.