By Craig from Newark, Delaware on January 19, 2014
I am looking for a way to provide outside air to an old fireplace in our very tight house. When we have a fire, smoke goes up the chimney and then is sucked down the adjacent chimney flue for a wood burning stove on a lower level of the house. The smell is awful and the only solution has been opening a window. We have a cleanout space underneath the fireplace that is accessible from a stairwell behind the fireplace. I could run a duct from the attic, down the stairwell wall, through the cleanout wall and up into the front of the fireplace floor. The duct length from the attic crawl space to the cleanout is about 9'. The attic is well ventilated by three large vents. Can you offer suggestions or provide guidance?
By Collin C. - NFI Master Hearth Professional on January 20, 2014
Answer:Based on the length of the incoming air duct, this should indeed solve your problem. Typically, a 4 inch supply vent is used as standard, but a pair of supply tubes of equal area could be substituted if the diameter is a problem. This is very much a custom installation and I can offer support for issues you may encounter when routing the duct, but a custom supply grate will likely be needed.