I'm deciding to build a green house to grow some of my favorite plants. My place is quite hot and dry, and water is very precious. My priority is to keep humidity inside. But I couldn't find a solution about that. The normal green houses use fans and open windows to replace hot air with cool air from outside to control the temperature. But I guess ventilation like that means losing humidity which makes it require more water insertion into the green house.
Is there any design or solution for this? Or maybe I'm not considering something here?
update
I guess I should have explained more that I'm more interested not to lose water instead of having a very humid green house. I don't want to face a dried green house that needs watering several times a day.
I thought that a humid air will keep the pots from drying off, but now that it introduces the danger of fungus, I think an AC will be the best Idea here; Both to cool the air and converting humidity into water for later use.