[Sheesh]

Two years ago I had my old gravity furnace ripped out and replaced with a new furnace. There were new lines routed to the main floor and a couple to the second floor. The first floor heats and cools great. The master bedroom and second bedroom are also very good. My third bedroom isn't that great.

For all of the first floor the old supply vents became the cold air returns. The Master bedroom and my son's room have new supply ducts installed and the old shared vent from the old furnace which became a cold air return for the two rooms. The third bedroom and bathroom share a vent and it is the original vent from the old furnace. It is the supply vent for the two rooms. Since we used the old vent to carry the heated/cooled air, there is no cold air return for these rooms.

The bathroom is fine as long as the door remains open at times. The third bedroom is for my 2 year old daughter and I can not keep the door open as I do not want her falling down the stairs.

The supply for her room is directly over the furnace and is a straight run from the basement to her room.

What I am thinking is getting two ceiling vents, some 4" metal ducting, 2 elbows, insulation for the duct and an in-line blower. I want to put one vent in her room and run it to my hallway. I will use the in-line blower to exhaust the air from her room out to allow for a slight negative pressure in her room to allow for the hot/cold air to flow better.

Would this in fact work? I think it would kill two birds with one stone because it would allow for more airflow in the hallway and keep her room warmer/cooler due to the exhausting of the air.

What I would also like to do is to put in a variable switch in to match the inlet/exhaust levels to the furnace. Also I am thinking of running a line up from the furnace to the attic to act as a trigger to start the fan. I will have a relay start the fan when the furnace fan kicks on and turn it off when the furnace is off. That way I don't have to remember to turn it on and off all the time.

Any ideas would also be appreciated.

Thanks

[hkstroud]

Should work but sounds a bit complicated. Since keeping the door open give satisfactory heat and cooling balance, I would just run duct work from the bedroom ceiling to the hall ceiling. If that does not work to your satisfaction you could then install the inline blower.

[hvac1000]

The third bedroom is for my 2 year old daughter and I can not keep the door open as I do not want her falling down the stairs.

Eventually the child will be able to open that door unless you lock it and I know you do not want to do that. You can get a very secure baby gate and this will allow the door to be left open to circulate the air. Just a passing thought since it worked many years ago at my own home.