I know a commercial panther breeder who keeps panthers in a green house. He lives in a much hotter place than I do. He uses a mist system to cool the green house when temps get too high, also runs huge fans in there. To me it is unbearably hot and humid in there. He is continuously dealing with URIs in the summer time, but not in the winter when he has to heat the greenhouse. Your conclusions?
We're all still trying to get this right. And we are doing much better than 25 years ago. I'm sharing my experiences. I've definitely noticed since starting the fogger my panthers drink less water from daytime spray misting than before foggers. I've also cut back on daytime misting and do not experience the URIs I did with young panthers when heavily misted during high daytime temps.
I also understand that these are my interpretations of my experiences.
Well my conclusion would require the rest of the story.
I'm in alot of groups, for plants. Heated greenhouses are still kept at 100% humidity. High humidity plants still need the humidity whether it's winter or not. Thats actually a very common struggle of greenhouse owners, and a common question.
So I am not sure, of the question. Is the ideal that he doesn't raise the humidity during the winter? If he does, than Saltys point has more standing, which was the other reason I have also thought as possible.
In your Winter vs Summer theorium we have different factors at play.
In the Summer, the heat is coming from the roof of the greenhouse, and since the roof is what is heating it, there is no escape, isnt that why attics are a thing? And summer cooling is needed. The chimney effect fails in this situation.
In the winter, we see him artificially heating his greenhouse. Now we have a chimney effect, since the heat is starting at the bottom, and rising so is the air. So the air is being exchanged at a much faster rate than it would in the summer isn't it? Hot air rises, and prevents the air from being stagnant. Even just the air being moved, should help with stagnation, I think, maybe.
A good test to this theory, that you friend could try, is to add a ceiling fan to his Greenhouse. This would keep air moving, which would help prevent stagnation, it would also be beneficial in the winter to keep heat in, and cool some in the winter.
We see this play out with some Neps and Orchids. They want 100% humidity at all times, they also want high heat, and they also want Ventilation and will perish from stagnant air. I have seen growers of some, use waterproof fans in the pretty much sealed Vivarium to prevent stagnation, and it seems to work?
To be clear, I am not Knocking the Fogging at night thing at all, or thinking it doesn't work. It makes sense that it would work. The theory makes complete sense.
The theory that high humidity plus high temps, or that misting during the day causes RIs is what baffles me. That makes no logical sense, seeing where Panthers hail from.