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Conservation: Home Heating

Distribution systems carry the heat from the furnace to the living space. The two most common distribution systems use either air or water. Air-based systems are often called "forced hot air" because they use a fan to push the air from the furnace through the ductwork to the several rooms of your home. Water-based systems are often called "hydronic".

Forced hot air systems are far more common than hydronic systems because they cost much less to install. However, hydronic systems perform better than forced hot air because they leak less heat, are easier to insulate, make almost no noise, can easily heat only a portion of the whole house and can provide more even temperatures. Hydronic systems also do a much better job of serving a radiant heating system.

Forced hot air
Forced hot air distribution systems consist of:
  • A heat exchanger
  • A fan
  • Ducts to carry heated air from the furnace to the living space
  • Hot air supply vents in the various rooms of the house
  • Furnace return air registers
  • Ducts to bring air back to the furnace
  • Some kind of air filtering device
  • Thermostat to control temperature
A properly designed forced hot air distribution system will provide for a balanced flow of warm air to the living space.

Hydronic distribution systems consist of:
  • A heat exchanger
  • A pump
  • Pipes to carry the heated water to the living space and back to the boiler
  • Valves to control the flow of water and to allow air to be bled out of the system
  • Heat registers in the living space

For more information from Seattle City Light on home heating, please
e-mail or call 206.684.3800.
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