How warm is it in that boiler room? How steady is the room temperature? Your goal in any brooder is to provide one spot warm enough in the coolest temperatures and a different spot cool enough in the warmest temperatures, so the chicks can find a comfortable area. The bigger your temperature swings the harder that can be to accomplish.
A broody hen can raise chicks in below freezing weather or in ridiculous heat waves. The chicks can tolerate a wide range of temperatures, there really isn’t any perfect temperature for a brooder. But too much heat can stress them just as much as too little heat. That’s the beauty of providing one area warm enough and one area cool enough, it takes the stress out of it for them and you. You don’t have to be perfect, you just need to be good enough.
I use a heat lamp, much as people have been successfully doing for over a century. There are plenty of other ways to provide heat, any of them can work. But you mentioned heat lamps so I’ll discuss that. To me the most important thing to do with a heat lamp is to immediately throw away that clamp that came with it so you are not tempted to use it. Securely wire your lamp in place so neither you nor anything else can knock it down. Use wire, not string, so it will not burn into and the lamp fall. Wire it to something secure.
The next thing is to make sure your brooder is big enough so you can heat one end and the other cools off. How big that needs to be for this purpose depends some on how big your temperature swings are. In warm weather you may wind up overheating one area but as long as they can get to a cooler area they will be fine. You can adjust how much heat your lamp is putting into that area by using different wattage bulbs, raising or lowering the lamp, or maybe positioning it so not all the heat goes into the brooder.
How long do you plan to keep them in the brooder? They are going to grow extremely rapidly. At what age will you take them out? I don’t have any magic square feet per chick based on age you need, there are factors that will affect that. The bigger you make it the longer they can stay in it. I’m always in favor of bigger, it reduces your stress levels. It needs a cover too. They will be able to fly at a surprisingly young age. I’ve seen two week olds fly up two feet vertical and three feet horizontally.
You need to keep the brooder dry. A wet brooder is a dangerous brooder. It can become wet from their waterer or if their poop builds up very much. The bigger the brooder the slower that poop will build up, which can have an effect on how often you need to clean.
We have all kinds of different waterers, I don’t know which one you plan on using so I can’t be too specific. Make sure it doesn’t leak, which usually involves keeping really level. They scratch a lot and will scratch bedding into your waterer if they can. I solve that by raising the waterer up to about the level of their back. I also use a piece of plywood to center the waterer to try to keep some of the shavings further away.
I built my brooder into the coop. A popular method, if you have room in that boiler room, would be to get an appliance box to use, putting cardboard on the floor and covering it with bedding so their poop doesn’t stain your floor. Freezer and refrigerator boxes form your local store that sells them are really popular. If they outgrow it, get another and tape the boxes together.
A standard way to feed chicks is to start them off with Chick Starter. That probably is about a 20% protein level. Then hen that bag runs out, usually between 4 and 8 weeks, switch to a Grower ration, usually around a 16% protein level. Some people feed the higher protein feed forever. There are no hard and fast rules about this except do not feed growing chicks Layer. Which has a high calcium level, usually around 4%. Too much calcium can damage their internal organs or skeleton.
There are all kinds of different homemade feeders and waterers used. For water I take a pet bowl and fill it with rocks so they can walk on water and not drown. I center that on a piece of plywood to reduce bedding being scratched in. This is actually for adults but maybe you can get the idea.
For what it’s worth to you, this is my brooder in the coop. It probably will not help you much.
As with practically anything with chickens there are all kinds of ways to do any of this. Good luck!
