The Federal Energy Management Program (FEMP) provides acquisition guidance for residential gas furnaces, which is an ENERGY STAR-qualified product category. Federal laws and requirements mandate that agencies meet these efficiency requirements in all procurement and acquisition actions that are not specifically exempted by law.
Most manufacturers display the ENERGY STAR label on complying models. For a model not displaying this label, check the manufacturer's literature to determine if it meets the efficiency requirements outlined by ENERGY STAR.
Meeting Efficiency Requirements for Federal Purchases
Visit the ENERGY STAR website for the most up-to-date residential gas furnace efficiency levels and product specification information, and a list of qualified residential furnaces.
Buying Energy-Efficient Gas Furnaces
ENERGY STAR's Product Specification applies to residential furnaces that operate on propane or natural gas and have heat input rates less than 225,000 British thermal units per hour (Btu/h). When buying gas furnaces directly from commercial sources, specify or select products that are ENERGY STAR-qualified. Look for the annual fuel utilization efficiency, or AFUE, on the yellow EnergyGuide label required on these products.
These requirements apply to all forms of procurement, including guide and project specifications; construction, renovation, repair, energy service, operation and maintenance contracts; lease agreements; and solicitations for offers. Energy performance requirements should be included in all evaluations of solicitation responses. Buyers shall insert the standard clause from FAR section 52.223-15 into contracts and solicitations that deliver, acquire, furnish, or specify energy-consuming products for use in federal facilities. Agencies can claim an exception to these requirements through a written finding that no ENERGY STAR-qualified or FEMP-designated product is life cycle cost effective for a specific application.
All models that meet the ENERGY STAR product specifications are "condensing" furnaces. This technology takes advantage of normally exhausted heat in the furnace's flue gas to improve efficiency. When installing condensing furnaces, select products that feature sealed combustion. Condensing furnaces should not use indoor air, which frequently contains contaminants from common household products, for combustion. These contaminants can cause corrosion and damage condensing furnaces. Furnaces with sealed combustion have supply lines that bring outdoor air directly to the combustion chambers.
In addition to improving efficiency, condensing furnaces with sealed combustion are safer. The supply lines, combustion chambers, and flues are sealed from the inside of homes thus preventing exhaust gases from leaking or being back drafted into occupied spaces. Due to these features, condensing furnaces require slight modifications with installation and are usually more expensive than standard efficiency models; however their increased efficiency means they are typically life cycle cost effective.
When buying or specifying new gas furnaces, consider the efficiency of the blower fans as well. The electrical energy used to run these fans and distribute the heated air throughout homes can be substantial. The Consortium for Energy Efficiency (CEE) and Gas Appliance Manufacturing Association (GAMA) recommend that annual electricity use (EAE) be less than or equal to 2% of the total annual energy use of the furnace. To find qualified products, go to the GAMA website and download their Consumer's Directory of Certified Efficiency Ratings for Heating and Water Heating Equipment. Models designated with an "e" in the EAE column meet this criterion.
An efficient furnace will not save energy or money if it is not properly installed. Federal procurement officials and buyers should require that gas furnaces be installed in accordance with the HVAC Quality Installation (QI) Specification published by the Air Conditioning Contractors of America. Installation problems like oversizing, poorly designed distribution systems, and leaky ducts result in efficiency losses, occupant discomfort, and shortened equipment life. Requiring the contractor to follow the HVAC QI Specification will ensure that these and other problems are addressed and the expected energy and cost savings are achieved.
Properly sealing the building envelope and weather-stripping doors and windows can result in additional savings, and may allow for the use of a lower capacity furnace, resulting in even further savings. Consider leaving your furnace off during unoccupied hours or using a programmable thermostat to minimize unnecessary operation. Regular maintenance is necessary to maintain peak performance.
Estimating Energy and Cost Savings
ENERGY STAR has an Excel-based cost calculator for furnaces To modify the utility price, go to and click on "Savings Calculator" in the column on the right. Input the appropriate location of your facility and rate for natural gas. The output section will automatically display results that more accurately reflect your energy use and cost.
Lawrence Berkeley National Laboratory provided supporting analysis for this acquisition guidance.