what is the halachah in regard to who takes preference when one person wants to open say a window or door to a room because they are feeling hot inside and another person is feeling cold if the window or door is opened ? What is the source for this ruling ? thanking you
Your question is spoken about in Halichos Bein Adam L’chaveiro 17-16 (R’ Fuchs). He writes, that if one person want the window open or closed and there are others there that object to it, in the winter the person that wants it closed has the upper hand to have it closed even though other say that it isn’t healthy for them. (The same would apply to turning on a fan in the summer, see Shevet Halevi 9-298). However in the fall or spring both sides have equal rights, and they should come to some compromise, or one side should just give in. If however there is a person there that is sick, then he has the preference and he should be listened to.
As a general rule, we should try to be forthcoming to the other person, and try to avoid machlokes and paining others.