[color=#383a3b]So, we just moved. We were forewarned. When we came for the inspection, the previous owner was here. He voluntarily told us the master bedroom doesn't cool as well as the rest of the house. He's right. It's always much warmer in the master bedroom. Vents are all open. I've heard trying to close vents don't really always do what you think they'll do. Just makes your furnace work harder, higher energy bills, and probably won't see much gains. Not sure if that still holds true.[/color] [color=#383a3b]We have one of those all-in-one outside furnaces that seems like all houses in the south have. The furnace is on the opposite side of the house. Our last house, we had two furnaces... one for upstairs and one for downstairs. That house was a two level without a basement. The house we're in now has a main level and a basement. So, the furnaces comes in through the upstairs floor and I'm sure has ducts that shoot up and down to the different rooms on different floors.[/color] [color=#383a3b]I think possibly one of the biggest issues is the cold air return is on the opposite side of the house. If I could have the hot air being pulled out of the side of the house where the master bedroom is at, then there would be a jet stream of air flowing through the house towards the cold air return. But, that is not how it's setup.[/color] [color=#383a3b]Don't know if anyone has any great ideas short of having a ton of tower fans all over creating a jet stream from the one side of the house to the other.[/color]

I'm normaly not a fan (no pun intended) of things like this, but I think I have a situation where this might be required and necessary. The short version is that we have retrofitted central AC into a house that was built in the late 1800's. As such, one room had no AC register due to structural limitations. The warm room got to be a troublesome issue for me, so we tapped off the bathroom duct, went between the second floor joists and got a box and register installed. The issue is that the feed from the AC unit is a 9" duct that we 'wyed' off of and then had to go down to a 5" duct to get to the bedroom another 4' away with a register boot fished between the floor. When we did this, we essentially get the bathroom air in the bedroom. This was expected and acceptable. But, that air for a bathroom is plenty, for a bedroom, not so much. However, we cannot put a bigger duct or register in, it's not possible. Everything is duct tied and sealed with mastic, so all available air is coming out. So, I was wondering if a 9" duct booster fan in the supply duct for that room might address the problem? Is this a suitable application?