I imagine that would be pretty difficult to do in a chicken coop. These are barns made out of corrugated steel and generally aren't even remotely air tight. You will, ultimately, need about 10x the nitrogen you would otherwise need, and that's if it even works.

So a special coop would need to be built for this purpose.

Chicken farmers are some of the poorest farmers in the country. They generally don't have the means to build a special kill shed to humanely euthanize their flock. They barely have the means to keep up with Tyson and Perdue's ridiculous bullshit.

So, while I agree, heat stroke is a fucking awful way to kill these animals, the issue isn't just "there's a humane method bro, just build a kill house bro"

The issue is, we are paying FAR too little for chicken, and most meat, honestly.

I imagine there are a handful of ways to do it besides “long, slow heat stroke”

Doesn't sound as cheap as running the heater for a few hours.

Carbon monoxide would be cheaper. We used it for euthanizing animals that couldn't be saved at the wildlife rehab center I worked at. Though, it was done with sealed induction box, not a drafty barn like someone mentioned

Nitrogen is expensive and these buildings aren't airtight

Those big coops are not anything close to airtight. Heat, however, doesn't require it to be airtight.

wouldnt that be more expensive than just cutting off the ventilation? on top of paying for disposal afterwards & whatnot?