This building has a big hole in the ceiling air barrier. Now the thermal envelope is extended to the weather shell. Roof venting results in large exhausts of heated air. These losses are balanced by high negative pressure and infiltration through the bottom of the envelope.
The existing attic insulation is now hovering between two heated areas.
The NPZ is located somewhere in the middle of the heated area. Some of the living area will be pressurized, but most will be depressurized.
The lower areas are constantly bathed in the flow of outdoor air. This makes living there cold and dry.
If this is a cellar, soil gas will be sucked into the living space. Water vapor, radon, pesticides, spilled fuel, and mold can be found in soil gases.
The uninsulated roof is heated
and melts snow into roof ice.
