ishiboo
Well-known member
I am in the process of finishing a complete renovation of the second floor of my house. It was previously an up/down split duplex, and will now be one home.
The existing furnace was a 70,000 BTU, 80% efficiency which heated the upstairs satisfactorily. At that time, the walls were uninsulated, the windows were 50/50 new vinyl and original single pane, and the ceiling was very poorly insulated.
The upstairs is now 2x6 walls with R19, brand new low-E aluminum-clad wood windows, and R-19 base in the attic which will be blown to R-60 when the duct work is installed.
I am going with a new 2-stage, 95% efficient furnace. It seems to be that a 46,000/32,000 BTU will be plenty sufficient, especially since being opened to the downstairs, heat will come from the downstairs furnace system. However I am concerned and don't want to undersize. Air will be fed from the ceiling.
Does 46/32k BTU 2-stage sound like it will be plenty?
The existing furnace was a 70,000 BTU, 80% efficiency which heated the upstairs satisfactorily. At that time, the walls were uninsulated, the windows were 50/50 new vinyl and original single pane, and the ceiling was very poorly insulated.
The upstairs is now 2x6 walls with R19, brand new low-E aluminum-clad wood windows, and R-19 base in the attic which will be blown to R-60 when the duct work is installed.
I am going with a new 2-stage, 95% efficient furnace. It seems to be that a 46,000/32,000 BTU will be plenty sufficient, especially since being opened to the downstairs, heat will come from the downstairs furnace system. However I am concerned and don't want to undersize. Air will be fed from the ceiling.
Does 46/32k BTU 2-stage sound like it will be plenty?