heating and cooling zones for your home

Heating and cooling zones are areas of the house - isolated from other areas – where you can have different temperatures, responding to different needs and to energy saving goals. You may have, for instance, a zone 1, comprising the living room, a zone 2 involving the bedrooms, and a zone 3 for the kitchen and bathrooms…  with different temperatures during specific parts the day. That's zoning.

The goals of heating and cooling zones
 Heating and cooling zones are a way of getting energy savings, energy efficiency and more comfort.

The number of heating and cooling zones

Obviously, the number of heating and cooling zones varies with the type and size of house, design considerations, levels of insulation and patterns of occupancy.

In most cases, two or three zones are sufficient, but larger homes and very specific situations may justify more zones. You may have, for instance, a room with large amounts of sun-facing glass, that doesn't need as much heat in winter as other rooms. In that case, that room alone can be defined as a separate heating and cooling zone…. An example of zoning
Suppose you have a two-story building, and you and your family are out of home most of the day. That may justify a simple system with just two heating and cooling zones, and a simple pattern of temperatures for each of them: the main floor (with, say, the living room, kitchen and dining area) zone, with a comfortable temperature during the evenings (when it is occupied); and the upper floor, involving the bedrooms, with a comfortable temperature at night and in the early morning. When unoccupied, the two zones can be set to a low yet comfortable temperature - typically between 60º-80ºF/18°C-21°C – for energy savings (temperatures in the colder parts of a home should be set at least to 50°F/10ºC, to prevent freezing problems; unused rooms should not be permanently and entirely unheated (in very cold climates), to avoid water to freeze in the pipes or other problems).

Room occupancy

Many homes are zoned according to room occupancy (the example in the box at right is largely a response to room occupancy). You will save money by lowering the temperatures in the unoccupied parts of your house.

But there are other elements to consider when defining heating or cooling zones, namely your climate and the design of the house and its insulation and air sealing levels.

Heating and cooling zones separation: doors and insulation

Zoning works best in homes properly designed to support heating and cooling zones. If may be difficult to implement zoning in houses without proper insulation and air sealing or where the different areas aren't insulated from each other. In such cases, leaving a zone at a lower temperature can cause discomfort in adjacent rooms, due to cold air flowing.

Similarly, if we can’t isolate a zone by closing their doors, the whole system will not function properly (implementing heating and cooling zones may demand new doors...).

Heating and cooling Zone Elements

You can get your heating and cooling circuits and zones by using a central furnace, and dampers and a programmable thermostat in each zone. A good HAVC professional can do it with relative ease. But there are other solutions...

If you have a boiler or other hydronic hot water heating system, you may install automatic valves on the hot-water radiators or baseboards and control the circuit by thermostats in each zone.

You may also use space heaters, and combine them (or not) with a central heating system, to get your heating and cooling zones.

Or you may use multi-split air conditioners (or ducted air conditioning), and also evaporative coolers, ceiling fans and other types of fans and cross-ventilation, according your climate, to get cooling zones.

See, for details on these issues:
Cooling zones
Zone heating with furnaces, ac and central systems
Zone heating strategies with space heaters