I was visiting an expert in energy utilisation recently whose office had a) a very high ceiling and b) a fan heater running full blast under the desk.
My irony indicator went FSD and set me thinking about the energy which is wasted in heating the upper portions of rooms which were designed in an era when their occupants wore multiple layers of tweed and rarely disrobed (bathing being a well known source of moral delinquency).
Today’s invention is a way to keep people in tall rooms warm in winter. It consists of an inflatable bladder attached to the ceiling. This would be filled with (low pressure) air and would thus temporarily lower the ceiling height of any room to which it was fitted. These bladders could be constructed of low-conductivity material using the carpet as a template.
It might be more convenient to simply supply a number of cuboid, air-filled sacs, each of which could be attached to the ceiling using eg velcro or double-sided tape.