Hi Mark
There really shouldn't be noticeable odor from your tank, especially if you keep up on tank maintenance. If you cure live rock in your tank, it's going to smell until it cures. Mine hardly smelled at all, some people have had it smell like a sewer. If you are really concerned about odor, going with cured live rock would be your best bet. There will be odor from your skimmer collection cup and that's not pleasant but as long as you empty it regularly and especially if it's in an under-the-tank sump in a closed stand, you shouldn't smell that in the room.
As far as "the green house effect", well, it is going to heat up the room a little and you will notice some humidity but it's not bad by any means. I don't have air conditioning in my house and when I come home and the house has been closed up all day it's definitely time to open a window but I don't feel as if I've stepped in to a sauna or greenhouse. The bigger the tank, the bigger the effect, however.
Hope this helps,
~Alice