We designed our house to include multiple energy saving features in addition to tapping into solar energy. One of these features is a central heating system that heats an area only when we intend to be in that area.

Heating control

The computer for the heating control system operates according to pre-programmed information.. One packet of information is a schedule that indicates when a zone is expected to be occupied.

The house is divided into six zones for individual heating control. When an area is to be occupied, a computer opens a valve that allows hot water to flow through the radiators for that area and the temperatures rises to a preset level. When we are away at work, each zones is considered unoccupied and the central heating system allows the temperature to drop. A schedule of occupancy for each of these parts of the house ensures that my wife's office and the living area are cozy during the times she is occupying one or the other. The schedule for the master bedroom indicates occupancy for only a couple of hours in the evening. So long as it is reasonably comfortable when we jump into the bed, we're fine – we like sleeping in a cool room.

You might wonder how much heat transfers through the interior walls from one zone to another. The answer is very little because we filled most interior walls (both bathrooms and the master bedroom) with fiberglass insulation. This keeps heat where it is intended and allows different areas to remain at different temperatures.

It means no area is warmer or cooler than we want it to be. And that an area isn't heated unless we are present.

Here's a graph of the temperature in one zone over several days. Click here for a larger graph of indoor temperatures for several days.