Residential and Light Commercial Forced Air Heating and Cooling Systems
ASHRAE Technical Committee 6.3

Scope of TC 6.3

TC 6.3 is concerned with those central forced air systems used for residential and light commercial building comfort heating and cooling. Responsibility covers the design and performance of the entire system, including equipment, controls, ducts and the interactions of the system with building heating and cooling loads.


The ASHRAE Handbook is published in a series of four volumes, one of which is revised each year, ensuring that no volume is older than four years.

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HVAC Systems & Equipment: Small Forced-Air Systems

This chapter describes the basics of design and component selection of small forced-air heating and cooling systems, explains their importance, and describes the system’s parametric effects on energy consumption. It also gives an overview of test methods for thermal distribution system efficiency, and considers the interaction between the building thermal/pressure envelope and the forced-air heating and cooling system, which is critical to the energy efficiency and cost-effectiveness of the overall system. This chapter pertains to residential and certain small commercial systems; large commercial systems are beyond the scope of this chapter.

HVAC Systems & Equipment: Furnaces

Furnaces are self-enclosed, permanently installed major appliances that provide heated air through ductwork to the space being heated. In addition, a furnace may provide the indoor fan necessary for circulating heated or cooled air from a split or single-package air conditioner or heat pump.

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Technical committees develop and sponsor technical sessions at the winter and annual conferences. Information about their future technical program is discussed at each TC meeting and at the TC’s Program Subcommittee meeting.

ASHRAE publishes papers and transactions from presentations at its conference events. In addition, ASHRAE records most of the seminar sessions from its conferences on DVD. These DVDs are ideal for use at chapter meetings, in university courses, or company lunch and learns. Products available from the most recent conference may be found here.


Technical Committees are responsible for identifying research topics, proposing research projects, selecting bidders, and monitoring research projects funded by ASHRAE. Information about their specific research program is discussed at each TC meeting and at the TC’s Research Subcommittee meeting.

To learn more about TC 6.3's research download TC6.3 Research Strategy and TC 6.3 Research Plan (2011).


ASHRAE writes standards for the purpose of establishing consensus for: 1) methods of test for use in commerce and 2) performance criteria for use as facilitators with which to guide the industry. ASHRAE publishes the following three types of voluntary consensus standards: Method of Measurement or Test (MOT), Standard Design and Standard Practice. ASHRAE does not write rating standards unless a suitable rating standard will not otherwise be available. ASHRAE is accredited by the American National Standards Institute (ANSI) and follows ANSI's requirements for due process and standards development. Standards may be purchased at the ASHRAE Bookstore.

TC 6.3 is cognizant for the following standards:

ANSI/ASHRAE Standard 103: Methods of Testing for Annual Fuel Utilization Efficiency of Residential Central Furnaces and Boilers, Methods of Testing for Annual Fuel Utilization Efficiency of Residential Central Furnaces and Boilers

ANSI/ASHRAE Standard 152: Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems

ANSI/ASHRAE Standard 193: Method of Test for Determining the Airtightness of HVAC Equipment (TC 4.3 Co-cognizant)

Other Activities

TIP: If MTG involvement add here otherwise leave blank.

TC 6.3 participates in the following multidisciplinary task groups:

Cold Climate Design Guide
MTG.CCDG will coordinate TC/TG/TRG technical activities to help support the technical basis, development, and publication of a “Cold Climate Design Guide” in conjunction with REHVA and SCANVAC. Responsibilities include the development of supporting research, presentations, and content for the “Cold Climate Design Guide” special publication.

Operations and Maintenance Activities That Impact Energy Efficiency
MTG. O&MEE will coordinate TC/TG/TRG activities to help support the application of ASHRAE guidelines, Standards and other technical resources to support regulatory bodies, utilities, building owners and others who are attempting to enhance efficiency of existing buildings. Responsibilities include suggestions for research, development and presentation of technical programs of all types on maintenance and its impact on energy consumption and efficiency. It will be especially involved with interactions with those who are introducing and evaluating strategies for building efficiency enhancements.


ASHRAE Technical FAQs are provided as a service to ASHRAE members, users of ASHRAE publications, and the general public. While every effort has been made to ensure their accuracy and reliability, they are advisory and provided for informational purposes only, and in many cases represent only one person’s view. They are not intended and should not be relied on as an official statement of ASHRAE. Technical questions not addressed may be submitted to the ASHRAE Technical Services department at