Zoning

Spending a little extra on zoning a duct system can provide a considerable increase in comfort for relatively little increase in cost. It can also reduce the heating and cooling running costs. A duct system with zoning allows the occupants to adjust the temperatures of the rooms, or groups of rooms, independently of each other. It also can help to overcome the common problem of upper rooms or rooms on the south and west side of the house being too hot. Conventionally only large houses were zoned but it has now been shown that even quite small houses can benefit from zones even if only the floors are separated.

Zoning usually involves the installation of some extra ducting plus a damper for each zone which is controlled by a separate thermostat located in an optimum position in the zone. The damper then allows air to flow into the zone independently of the other zones when called to do so by the thermostat. Only when all zones are up or down to their desired temperatures does the heating or cooling source turn off.

Deciding on how the rooms of a house should be zoned depends on several factors:

1. Their usage. Living rooms are often grouped together into one zone while bedrooms are grouped into another.

2. Rooms on one floor are often grouped together since the fact that heat rises tends to make upper floors too hot compared to a lower floor.

3. Rooms on one side of a house which have a lot of solar heat gain are often grouped together.

4. Rooms with large internal heat sources, such as computers, are often grouped together or a single room can be made into a single zone.

5. A room or rooms which will have a high moisture content, such as caused by a pool or Jacuzzi, should be zoned separately.

5. Cost can also be a factor since many zones will cost more and probably have little benefit.

Installing zones in a new house is easy but installing them in a retrofit can be difficult since the duct alterations can be difficult to make without disrupting the finished house too much. It is therefore strongly advisable to configure the ducting in a new house for zoning even if the dampers and thermostats are not installed immediately. Although retrofits are usually more difficult, there are ways to get round some problems without too much disruption so it is worth having your system checked out to see what is possible.