Bought a 1979 build in the suburbs of Chicago this past year. Lots of new things for me to fix/figure out but this one has me confused.
Furnace & AC are carrier units from 2016. Seem to function well with the typical low airflow to the second floor issues. In the basement the mechanicals are installed in an oversized “closet” that is approximately 8’ x 40’. My question concerns some really big ductwork. There is a 13” duct with damper with an exposed end in the closet. The route from the exposed end is up into the chimney chase (home has a wood framed chimney chase), across the back of the chase, down back into the basement closet, five feet horizontally, and then ties into the cold air return.
I don’t understand the point of this duct. Local HVAC company allegedly told the previous owner it was for “make up air” for original furnace. Newer furnace is a 98% model with pvc intake and exhaust piping. Make up air from the same closet doesn’t make sense to me. Reconnecting this ductwork to a new cold air return (from when the furnace/AC was replaced) doesn’t make sense to me.
Two issues I’d like to resolve;
1) The area around this duct has a number of gaps leading to cold air pouring into the basement from either the chimney chase or the outside. If not needed, my work sealing up these leaks would be much easier with the duct removed and out the way.
2) Could this duct be minimizing the cold air returns for the first and second floor? There are cold air returns in the basement plus this oversized monstrosity hidden away in a closet.
I’m aware of which contractor issued the original opinion and am searching for a reputable second opinion but have learned a great deal over the years from reading this website regarding my last house and thought some of you might have some thoughts.
Thanks in advance,
Dutch
Furnace & AC are carrier units from 2016. Seem to function well with the typical low airflow to the second floor issues. In the basement the mechanicals are installed in an oversized “closet” that is approximately 8’ x 40’. My question concerns some really big ductwork. There is a 13” duct with damper with an exposed end in the closet. The route from the exposed end is up into the chimney chase (home has a wood framed chimney chase), across the back of the chase, down back into the basement closet, five feet horizontally, and then ties into the cold air return.
I don’t understand the point of this duct. Local HVAC company allegedly told the previous owner it was for “make up air” for original furnace. Newer furnace is a 98% model with pvc intake and exhaust piping. Make up air from the same closet doesn’t make sense to me. Reconnecting this ductwork to a new cold air return (from when the furnace/AC was replaced) doesn’t make sense to me.
Two issues I’d like to resolve;
1) The area around this duct has a number of gaps leading to cold air pouring into the basement from either the chimney chase or the outside. If not needed, my work sealing up these leaks would be much easier with the duct removed and out the way.
2) Could this duct be minimizing the cold air returns for the first and second floor? There are cold air returns in the basement plus this oversized monstrosity hidden away in a closet.
I’m aware of which contractor issued the original opinion and am searching for a reputable second opinion but have learned a great deal over the years from reading this website regarding my last house and thought some of you might have some thoughts.
Thanks in advance,
Dutch