Sizing residential heating equipment has traditionally been based on weather design conditions, heating load, and field experience. This method is being restudied and changes will no doubt result.

The American Gas Association Laboratories' Gas Appliance Research adn Demonstration House was used to evaluate the feasibility of combining a pulse combustion space heater with a central furnace. The combination of these appliances, when operated in this 2500 ft² (232 m²) house, met the total heating requirement. A high efficiency, pulse combustion space heater functions as the primary heating appliance.

Data gathered during a "Family Occupied" period in the Gas Appliance Research and Demonstration House are presented in addition to other case studies. The value of the approach and problems associated with it will be discussed.

Units: Dual