How many zones and how many controls?
• At a minimum, each floor of a building should be on its own zone, as should any area that has very different temperature needs or heat loss characteristics. Such areas might include sunrooms, great rooms with cathedral ceilings, a room with a window wall and rooms with three walls subject to outdoor temperatures. Generally speaking, in an energy efficient building, temperatures will tend to equalize regardless of the number of zones. • The cost of each independent zone is $300-400. If you are in doubt about whether an area needs to be zoned separately, separate the plumbing but bring the lines back to one pump and control both with one thermostat. Use a balancing valve. If you later decide to separate the zones, you can do so for only the cost of a pump and thermostat-just what you would have spent had you done it initially.
