NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Water heating system energy use is typically the second largest in U.S. residences behind space conditioning (space heating and cooling). Recent advances are changing the way water heating service is provided. This article describes hot water demand in residences, discusses new options for providing hot water, and explains ASHRAE's role in the water heating industry.
Healy, W.
, Hiller, C.
and Lutz, J.
(2021),
How Residential Water Heating is Changing, ASHRAE Journal, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=931408
(Accessed October 14, 2025)