Originally Posted by paul52446m
You are not talking about ducting right to the stove Right?. You are talking about picking the hot air up by the ceiling Right?. First question is where does the stove get it burner air from? It could be dangerous if you pull air from this room and pull a vacuum on the room. Is this unit sealed combustion? or does the burner air come from this room? They do make blowers that develop higher static pressure. You did not tell me how big your home is so i can guess at how much air you are talking about moving.
If you are just moving air from the ceiling through the house, then you don't need fire dampers. If i could see a floor plan off the basement and the main floor, that would help. If you can get me more info and then we can go from there. Paul
The room already has free air flow to the rest of the house (open stairwell) and hot air central system returns. It is in conditioned space, I merely wish to circulate air in the existing conditioned space. Convection would help a two story house but convection doesn't help much on a long single story home.
I wish to pick up air off the ceiling of the downstairs family room and move it horizontally on a 72'x24' ranch and then through to the main floor.
Despite the fact that I have an open stairwell, my local inspector will not approve through floor (level change) ducts without fire dampers at each floor penetration. This is a tad ridiculous since the warm air heating system already has approved duct work that feeds the basement level family room and penetrates floors on the main floor! I'm just adding a second metallic air path! I can't use the existing duct since it would disturb pressures of my gas furnace.
The fire code he is citing regarding fire dampers (national code) is clearly written for commercial buildings, hospitals, multiple story apartments... since it is in the same section that requires fire doors on stairwells, fire rated walls and floors...
However, this section of the code does not include an explicit exemption for residential buildings. If the inspector is not happy, my fire insurance is void.
The existing warm air ducting is explicitly exempt (re fire dampers) under a clause that it is directly connected to a residential furnace with a 165F max safety cut off. Again, this duct system already connects the family room through he warm air ducts to main floor registers without fire dampers and meets code! Fire could follow that duct work or just go up the open stairwell!
My inspector will approve fans and ducts that penetrate the floor only with fire dampers. He rules!
I did cover the safety issues and keeping my home insurance valid. so back to the QUESTION!
Where can I find in line variable speed fans to move significant air through small diameter (4") horizontal ducts. Not just "booster fans", these will be the sole "air handler" fan for these ducts. High velocity/pressure is required to keep duct size small.