Zone Heating Increases Comfort, Helps Budget

QUESTION: We have a year-round problem keeping all our rooms comfortable. Some family members like it warmer and others cooler. Will adding a zoning system help this? Will it cut our heating and cooling bills?

ANSWER: The answer to both your questions is an unqualified yes. By installing a zoning system in the furnace/central-air ducts, there is no need for anyone to be uncomfortably hot or cold.

In addition to the comfort improvement, zoning can cut your heating and air-conditioning costs by up to 20%. The savings result from not overheating or over-cooling rooms and can easily pay back its cost several times over its life.

Zoning is a simple concept. With the use of motorized dampers in the ducts near the furnace, the amount of heated or cooled air flowing to each group of rooms (zones) can be precisely controlled. There is a separate thermostat in each of the zones to tell the dampers when to open or close.

A simple, low-cost two-zone system generally includes all the bedrooms in one zone and the living areas in another. More complex systems can have up to eight zones and can individualize the climate in each room.

There are hundreds of variations of designs and features for zoning systems. Some use a single master programmable thermostat in one zone with temperature sensors in the other zones. This keeps inquisitive little hands from tampering with the settings.

The most sophisticated zoning systems have automatic heating-to-air-conditioning changeover. During mild spring and fall weather, your husband may get hot in a sunny south-facing workshop while your children may be chilly studying in a north-facing bedroom.

If your husband’s workshop calls for cooling first, the central air conditioner will start and blow cool air only into that room. After it is cooled, the furnace will start and blow heat only into the kids’ bedroom.

One unique design uses low-cost pneumatic duct dampers without expensive motors. You install a low-cost damper in each room duct. This allows you to keep bedrooms at each end of your house warmer while one in the middle is cooler. One zone could actually include rooms on different stories.

Some systems use modulating dampers for good comfort and temperature control. Instead of each damper being either completely opened or closed, an electronic brain modulates how far the damper is opened. One room might get a little heat while another gets a lot--it is not all or nothing.

Write for or instant download (https://www.dulley.com) Update Bulletin No. 899, a buyer’s guide of 12 home zoning systems, number of zones, type and size of dampers, control/comfort features and a savings chart. Please include $3 and a business-size self-addressed envelope and mail to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, OH 45244.

Btu and What It Means in Terms of Energy

Q: I always hear about Btu on the news, from my air-conditioner technician, etc. How much heat really is in a Btu?

A: A Btu is a measure of heat energy. There is an engineering definition of exactly what it is, but in simple terms, one Btu is about the amount of heat produced when you burn one wooden stick match--not a lot.

Here are a few examples of Btu: heating a cup of tea, 500 Btu; burning one pound of wood, 6,000 Btu; using a gallon of gasoline, 125,000 Btu; heating a house in St. Louis for one year, 90 million Btu; the Apollo 17 moon mission, 5.6 billion Btu; an atomic bomb, 80 billion Btu.

Letters and questions to Dulley, a Cincinnati-based engineering consultant, may be sent to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, OH 45244.