This month's stump the chump comes from a mystery contributor, a caped crusading building performance specialist from Burlington, Vermont.
During a recent job, the crusader was reminded of a stumper he encountered in the late 1990's.
The homeowners of a 19th century duplex were in trouble; victims of uncomfortable rooms and high energy bills. With their patience wearing thin, they called in the local home performance hero to upgrade the shell of their home. The scope of work included significant infiltration reduction; upgrading thin rockwool attic insulation to R40; dense-packing 2x6 finished slanted ceilings with cellulose; dense-packing 2x4 exterior walls with cellulose; dense-packing the perimeter of the 2nd floor framing system with cellulose; R19 bandjoist insulation; and a few other minor things.
What a coincidence! I am working on a house very similar to this months stumper. I wish I didn't have to wait 'til next months newsletter comes out to know the answer. My thought is that they installed thermostatic radiator valves throughout the homes. Just having one thermostat control when every room gets heat sent to their radiators is going to result in many rooms, especially the upstairs ones, to become much warmer than what the one thermostat is calling for, which is likely located downstairs somewhere. This increase in delta T between the overheated rooms and the outside can dramatically increase heating use/cost.