Question: I live in Hinckley, Il. in a ranch house built in the arly 1990's. In the family room of the house is a "Dover sunburst 2100" fireplace, without an outside air inlet duct. When we use the fireplace the family room heats up to 80 degrees+ while the bedroom is at 68.
My chimney sweep raised the concern that an attempt to install an air inlet duct may damage the fireplace.Then hard to find parts from this no longer existing company. If I ran duct work in the attic from the family room to bedroom. Would this increase the heat into the bedroom ?
Thank you, John 

Answer: Hey John,
First, I would try putting your thermostat to the "Fan On" position. That will run the fan on the furnace even when it is not calling for heat. This might move enough air around to cool off the family room and heat the other rooms in the house.

If you want to try and move more air than that, you can put a fan in and duct to the bedrooms. If you can't go through the basement (First choice) then use insulated duct to run through the attic and wrap the fan with insulation. Something like this would work.
http://www.broan.com/products/product/205b8442-ec71-4b35-a9f6-53dd6e2409ef 

If you are looking to add makeup air to the firebox, I'm not sure that is a
good idea. Without approval from the manufacturer there is no way to know
how that would affect the fireplace.

Thanks for listening, R,R,R