Glass verses Plastic

My sunroom is glass,my greenhouse is plastic.
It seems the greenhouse warms up faster and gets hotter temps then the sunroom,and yet I have to water more in the sunroom than the greenhouse,which seems to be just the opposite you would think.I keep the humidity about the same in both of them,around 65%.
Does anyone have any clues to the reasons for this?

I guess my first and obvious thoughts would be: do both get the same amount of sun? I am also wondering if the sunroom is attached to your house and what the exterior wall of your house is made of as well as the floor of the sunroom. I am thinking if your house is say brick and the floor to the sunroom is cement, they may be leaching some moisture? In the same line of thinking, if you have gravel or mulch over fabric in the greenhouse, they could emit more moisture as it warms up. I think the amount of plants in each would also affect things. Does heat from you house escape into the sunroom? That could be drying as well. Gee, I have a lot of thoughts for someone that has neither. LOL

not to mention, glass lets in more light than plastic.
even when brand new, poly will only allow like 90%

Well let me see the sunroom does face south,is attached to a brick house and has cement floor with black indoor outdoor carpeting,greenhouse is half blocked by the house ,has a rubber liner floor,so sunroom does get more light,but less heat,plastic greenhouse heats up faster,with less sunlight,but the plants don't dry out as fast as the sunroom plants,I guess what I want to know in theory,does heat or more sun dry out the soil?Duh!!!I just figured this one out myself,I have 4 fans going in sunroom,which is 10x20,and 1 fan in 10x12 greenhouse,so it must be the amount of air bieng passed over the plants!!!Right?