The Federal Energy Management Program (FEMP) provides acquisition guidance for residential whole-home gas tankless water heaters, a product category covered by ENERGY STAR efficiency requirements. Federal laws and requirements mandate that agencies purchase ENERGY STAR-qualified products or FEMP-designated products in all product categories covered by these programs and in any acquisition actions that are not specifically exempted by law.
FEMP's acquisition guidance and associated ENERGY STAR efficiency requirements for residential whole-home gas tankless water heaters are technology neutral, meaning that one technology is not favored over another.
This acquisition guidance was updated in June 2016.
Find Product Efficiency Requirements
The U.S. Environmental Protection Agency (EPA) provides residential whole-home gas tankless water heater efficiency levels and product specification information on its 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 whole-home gas tankless water heaters to identify or verify complying models.
Make a Cost-Effective Purchase: Save $108 or More by Buying ENERGY STAR
FEMP has calculated that the required ENERGY STAR-qualified residential whole-home gas tankless water heater saves money if priced no more than $108 above the less efficient model. The best available model saves up to $208. Table 1 compares three types of product purchases and calculates the lifetime cost savings of purchasing efficient models for households with typical water use. Federal purchasers can assume products that meet ENERGY STAR efficiency requirements are life cycle cost-effective.
|Table 1. Lifetime Cost Savings for Efficient Residential Whole-Home Gas Tankless Water Heater Models|
|Performance||Best Available||ENERGY STAR||Less Efficient|
|Annual Energy Use||112 therm||123 therm||135 therm|
|Annual Energy Cost||$83||$91||$100|
|Lifetime Energy Cost||$1,003||$1,103||$1,211|
|Lifetime Cost Savings||$208||$108||======|
Energy Factor: A metric used to compare the energy conversion efficiency of residential appliances and equipment.
Annual Energy Use: Based on the test method referenced in 10 CFR 430, Subpart B, Appendix E and listed in therms.
Annual Energy Cost: Calculated based on an assumed price of $0.74/therm, which is the average natural gas price at federal facilities.
Lifetime Energy Cost: Future natural gas price trends and a 3% discount rate are from Energy Price Indices and Discount Factors for Life-Cycle Cost Analysis - 2015: Annual Supplement to NIST Handbook 135 and NBS Special Publication 709 (NISTIR 85-3273-30).
Lifetime Cost Savings: The difference between the lifetime energy cost of the less efficient model and the lifetime energy cost of the ENERGY STAR model or best available model.
Best Available Model Column
Calculated based on the April 2016 ENERGY STAR-Qualified Products List. More efficient models may be introduced to the market after FEMP's acquisition guidance is posted.
ENERGY STAR Model Column
Calculated based on April 2016 ENERGY STAR efficiency levels. Federal agencies must purchase products that meet or exceed ENERGY STAR efficiency levels.
Less Efficient Model Column
Calculated based on typical products used in non-federal applications.
There are additional cost savings associated with waste-heat recovery systems. Drain-water, or greywater, heat recovery systems capture the energy from waste hot water—such as showers and dishwashers—to preheat cold water entering the water heater or going to other water fixtures. Energy savings vary depending on individual household usage.