Since I have lived in my condo, 1 room is always warmer than the rest of the house. Luckily, I do not use the room everyday because it is my art room. But, if I spend more than an hour or 2 in there at a time, I start to get uncomfortably hot and begin perspiring. I checked the vents to make sure they were not closed. I had my HVAC duct and HVAC system checked by a HVAC professional also. I wanted to make sure that my ducts were not plugged with dust and debris. The HVAC professional could not find any troubles with the air conditioner and oil furnace and he checked every component to make sure. I brainstormed on why this 1 room was so much warmer then, if everything was working properly. I realized this room had many windows that faced the sun during the hottest time of the day. The room was also situated on the upper floor and since I think heat rises, this could be 1 of the reasons why the upper floor is a few degrees warmer than the first floor. So, I decided to make a couple easy inexpensive changes. I replaced the white sheer curtains with long and dark blackout curtains. These would keep the sun out and not allow as much heat to come through the windows into the room, raising the inside temperature. This did make a difference. I also installed a small window air conditioner. It only cost me a couple hundred dollars and I was able to install it actually on my own, without calling a HVAC professional. I can turn it on when I am in the room, and turn it off when I am not, so I won’t use a lot of energy. It has been working great. Now, I can spend all day in that room and do my paintings and feel cool and comfortable.