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HVAC in Single Family Housing

Boiler in a single family home.HVAC refers to the equipment, distribution network, and terminals that provide the heating, ventilating, or air-conditioning processes to a building. Your system may consist of a central unit with ducts that carry conditioned air to the living space, controlled by a programmable thermostat. Or you may have individual units that condition specific rooms, such as a room air conditioner or electric baseboard heat.

During any rehabilitation project, it is very important to assess the condition, reliability and efficiency of the heating system. Poor operation of the heating system will often lead to comfort problems for occupants, higher energy bills, increased maintenance demands and even structural problems from excess moisture.

Effect of Building Envelope

Install the proper level of insulation before conducting HVAC measures.When evaluating the overall efficiency of your HVAC system it is critical to consider related building components, including air sealing, windows and insulation. If your building envelope is leaky, conditioned air will escape and the mechanical equipment will work harder to compensate.

You should conduct any air sealing and insulation measures first before selecting a new HVAC system. You may be able to down-size your HVAC system by tightening the building envelope. This will save money on the initial investment as well as on your monthly energy bills.


Sometimes, existing equipment can be made more efficient by giving the heating and cooling systems a simple cleaning and tune-up. Basic repairs such as replacement of a faulty burner nozzle can result in significant savings.

New Controls

ProgrammableThermostat Don't forget to consider upgrading your controls. Programmable thermostats are a cost-effective measure for reducing energy consumption. The thermostat will automatically adjust the temperature during different times of day, to meet the occupants' heating and cooling needs while home, sleeping and away.

Other Considerations

Existing construction features can also have an effect on HVAC system type. Consider a house that has no chimney -- or a chimney in very poor condition. Equipment developed over the last 15 years or so may provide the answer. High-efficiency condensing appliances require only a sidewall vent rather than a chimney.

In the evaluation of existing systems, an experienced contractor may be able to provide helpful advice and guidance. For multifamily buildings, the size and complexities of the installation will typically require the assistance of a professional engineer.

For more information on the various components of your heating and cooling systems, follow the links to the right.

 Heating System Selection
 Cooling System Selection
 Multifamily HVAC
 Heating Tune Up
 Cooling Tune Up
 Duct Sealing and Insulation
 Air Sealing
 Programmable Thermostats
 Insulation Basics
 ENERGY STAR Heating and Cooling
 Right-Size Heating and Cooling Equipment: DOE Technology Fact Sheet
 Detailed overview of heating and cooling system components from DOE
 American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)
 Air Conditioning Contractors of America

Content updated May 28, 2009

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