Heating Forced Air

This old house, heating, ventilation, and air conditioning review-chapter six

In chapter six of “This Old House, Heating, Ventilation, and Air Conditioning,” the authors move into the concepts surrounding the installation of heating systems. Warm air systems are systems that have ducts, a central furnace, and a fan that propels air through the ducts.

The authors stress the notion that maintenance is important and provide a chart designating what should be done and who should do the work. The idea of performing regular maintenance is put forth as the most important thing that can be done for a home heating system.

It is explained that one of the most cost-effective improvements that can be made to a home heating system is the installation of an appropriate thermostat. Programmable thermostats are recommended, but others will do if they possess certain features.

Going further, the chapter talks about humidity, duct sealing, keeping the HVAC system in “balance,” and sealing off the furnace from the rest of the house.

Zoning is recommended by this chapter. The authors support the fact that dividing the home into two or three zones can allow a more precise control of comfort. Other subjects discussed include things to think about when evaluating your home HVAC system, how to select oil or gas furnaces, and features to look for when selecting a forced air system. Those features include…

  • A variable speed blower.

  • A built in humidifier.

  • A built in electronic air cleaner.

  • A strong warranty.

  • A reputable manufacturer.

As a final touch, the authors explain the types of information a contractor or HVAC installer needs to choose the appropriate heating system. The information needed include…

  • The outside design temperature.

  • The heated volume of the house.

  • That average wintertime infiltration rate.

  • The surface areas and the R-values of the floors, walls, ceilings, windows, and doors.

  • Some information about the family’s daily habits.

It is posited the general rule for sizing a unit is to match the equipment to the load rather than provide too much tonnage or capacity.