This page provides acquisition guidance for buying residential furnaces. Federal laws and requirements mandate that agencies purchase ENERGY STAR®-certified products or Federal Energy Management Program (FEMP)-designated products for all covered product categories except as specifically exempted by law.
FEMP's acquisition guidance for residential furnaces and the associated ENERGY STAR efficiency requirements apply to natural gas, propane, and oil-fired furnaces with heating capacities less than 225,000 Btu/h. Commercial furnaces (i.e., those with heating capacities of 225,000 Btu/h or greater) and weatherized furnaces are excluded.
This acquisition guidance was updated in December 2024.
How To Find Product Efficiency Requirements
The U.S. Environmental Protection Agency (EPA) provides residential furnace program requirements and efficiency criteria on the ENERGY STAR website. Manufacturers meeting these requirements are allowed to display the ENERGY STAR label on complying models. Federal buyers can use ENERGY STAR's list of certified residential furnaces to identify or verify complying models.
To reflect the influence of climate on furnace use, EPA specifies efficiency levels for furnaces in two regions: A southern region that includes the South and Southwest, and a northern region including the rest of the country, primarily the Midwest, Northeast and the upper northern states bordering Canada.
How To Determine Cost Effectiveness
An efficient product is cost effective when the lifetime energy savings exceed the up-front cost premium (if any) compared to a less efficient option. You can find more information about determining life cycle cost effectiveness on FEMP’s general federal purchasing requirement webpage.
Federal buyers may find the most relevant guidance in Tables 1 and 2 below based on the planned location of the installation. Each example compares the life cycle cost savings of a base model (less efficient than the ENERGY STAR required efficiency), a model meeting ENERGY STAR efficiency levels, and a model with the highest available efficiency.
Example 1: Northern Region
FEMP has calculated that the required ENERGY STAR-qualified residential furnace saves money if priced no more than $1,345 (in 2023 dollars) above the less efficient model. The best available model saves up to $1,635 (or $290 more than the required model).
The Northern Region includes Alaska, Colorado, Connecticut, Idaho, Illinois, Indiana, Iowa, Kansas, Maine, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, New Hampshire, New Jersey, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Dakota, Utah, Vermont, Washington, West Virginia, Wisconsin, and Wyoming.
Table 1. Lifetime Savings for Efficient Residential Furnace Models in the Northern Region
| Performance | Best Available | ENERGY STAR | Less Efficient |
|---|---|---|---|
| AFUE | 99% | 95% | 80% |
| Output Capacity | 70,000 Btu/h | 70,000 Btu/h | 70,000 Btu/h |
| Annual Energy Use | 502 therms | 523 therms | 621 therms |
| Annual Energy Cost | $482 | $503 | $597 |
| Lifetime Energy Cost (21 years) | $6,885 | $7,174 | $8,520 |
| Lifetime Energy Cost Savings | $1,635 | $1,345 | ====== |
Energy Use and Cost Assumptions
Annual Fuel Utilization Efficiency (AFUE): Ratio of useful energy output to energy input, expressed as a percentage (%), over the entire heating season.
Output Capacity: Shown in British thermal units per hour (Btu/h).
Annual Energy Use: Based on the test method referenced in 10 CFR 430, Subpart B, Appendix N.
Annual Energy Cost: Calculated based on an assumed natural gas price of $0.961/therm, which is the average natural gas price at federal facilities throughout the United States as of July 2024. Learn more about Federal Government Energy/Water Use and Emissions.
Lifetime Energy Cost: Assumed an average residential furnace lifetime of 21 years. Future electricity price trends and a 3% discount rate are from Energy Price Indices and Discount Factors for Life-Cycle Cost Analysis – 2024 Annual Supplement to NIST Handbook 135 (NIST IR 85-3273-39).
Lifetime Energy Cost Savings: The difference between the lifetime energy cost of the identified models.
Model Efficiency Levels
Best Available: Based on the model with the highest efficiency in the ENERGY STAR Qualified Products List as of December 2024. More efficient models may have entered the market after FEMP's acquisition guidance was created.
ENERGY STAR: Calculated based on December 2024 ENERGY STAR efficiency levels; values shown are rounded to the nearest dollar. Federal agencies must purchase products that meet or exceed ENERGY STAR efficiency levels.
Less Efficient: Calculated based on typical products used in non-federal applications.
Example 2: Southern Region
FEMP has calculated that the required ENERGY STAR-qualified residential furnace saves money if priced no more than $549 (in 2023 dollars) above the less efficient model. The best available model saves up to $947 (or $398 more than the required model).
The Southern Region includes Alabama, Arizona, Arkansas, California, Delaware, District of Columbia, Florida, Georgia, Hawaii, Kentucky, Louisiana, Maryland, Mississippi, Nevada, New Mexico, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, and Virginia.
Table 2. Lifetime Savings for Efficient Residential Furnace Models in the Southern Region
| Performance | Best Available | ENERGY STAR | Less Efficient |
|---|---|---|---|
| AFUE | 99% | 90% | 80% |
| Output Capacity | 70,000 Btu/h | 70,000 Btu/h | 70,000 Btu/h |
| Annual Energy Use | 291 therms | 320 therms | 360 therms |
| Annual Energy Cost | $280 | $308 | $346 |
| Lifetime Energy Cost (21 years) | $3,989 | $4,388 | $4,937 |
| Lifetime Energy Cost Savings | $947 | $549 | ====== |
Energy Use and Cost Assumptions
Annual Fuel Utilization Efficiency (AFUE): Ratio of useful energy output to energy input, expressed as a percentage (%), over the entire heating season.
Output Capacity: Shown in British thermal units per hour (Btu/h).
Annual Energy Use: Based on the test method referenced in 10 CFR 430, Subpart B, Appendix N.
Annual Energy Cost: Calculated based on an assumed natural gas price of $0.961/therm, which is the average natural gas price at federal facilities throughout the United States as of July 2024. Learn more about Federal Government Energy/Water Use and Emissions.
Lifetime Energy Cost: Future electricity price trends and a 3% discount rate are from Energy Price Indices and Discount Factors for Life-Cycle Cost Analysis – 2024 Annual Supplement to NIST Handbook 135 (NIST IR 85-3273-39).
Lifetime Energy Cost Savings: The difference between the lifetime energy cost of the identified models.
Model Efficiency Levels
Best Available: Based on the model with the highest efficiency in the ENERGY STAR Qualified Products List as of December 2024. More efficient models may have entered the market after FEMP's acquisition guidance was created.
ENERGY STAR: Calculated based on December 2024 ENERGY STAR efficiency levels; values shown are rounded to the nearest dollar. Federal agencies must purchase products that meet or exceed ENERGY STAR efficiency levels.
Less Efficient: Calculated based on typical products used in non-federal applications.
Where To Buy Compliant Products
Buyers can make sure the product they purchase will be compliant by incorporating federal acquisition regulation language into contracts. Compliant products can also be found using federal supply sources and product codes. See FEMP’s general federal purchasing requirements webpage for more details on buying compliant energy-using products.
Residential Furnace Product Codes
The Defense Logistics Agency Environmental Attribute Code (ENAC) identifies items with energy characteristics that meet standards set by an approved third party, such as FEMP and ENERGY STAR. Purchasers can also use a United Nations Standard Products and Services Code (UNSPSC) to identify and buy products and to track purchases.
The DLA ENAC for residential furnaces is "HG."
The UNSPSC for residential furnaces is 40101805.
Unified Facilities Guide Specifications (UFGS) section 23 80 20.00 10 has information regarding gas furnaces. These specifications are used in construction for the U.S. military services.
Buyer Tips: Make Informed Product Purchases
Tips for Selecting and Installing Furnaces
ENERGY STAR requirements for residential furnaces are divided into two regions as shown in the examples in Tables 1 and 2. More efficient models are required in the northern United States region due to the colder climate and greater number of heating degree days. In the warmer southern United States region where space heating requirements are less, a special ENERGY STAR logo is used to identify furnaces that qualify at the lower efficiency level. Residential furnaces with the southern United States region ENERGY STAR labels cannot be sold in the northern United States region.
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 for combustion. Indoor air frequently contains contaminants from common household products and can cause corrosion that damages 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.
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 ANSI/ACCA – 2015: HVAC Quality Installation Specification. 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 QI guidelines will ensure that these and other problems are addressed and the expected energy and cost savings are achieved.
Many states and electric utilities offer rebates or other incentives for the purchase of ENERGY STAR-qualified products. Use the ENERGY STAR Rebate Finder to see if your local utility offers these incentives.
Tips for Using Furnaces More Efficiently
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.