Disclosures
Who we are not affiliated with, how the site makes money, and what that never changes.
Independence
This site is not a manufacturer, a dealer, an installer, a utility, a trade body, or a government agency, and it is not funded by any of them.
Contact and corrections: [email protected]. What you may do with the site is set out in the terms of use.
How the site is funded
The site earns nothing from any link on it today. As of Oct 26, 2026 there is no revenue of any kind: no referral or affiliate links, no leads, no sponsorship, no paid placement, no subscription, no data licensing.
There are no referral links at launch. If one is ever added, this page changes first: it will name the partner, say what the link pays for, and label the link itself. A reader will never meet a paid link that this page has not already described.
No manufacturer, distributor, dealer, or installer has paid for anything here, and none has been shown a page before it went up.
What a commercial relationship never changes
These rules are written down now, while there is no money on the table to argue with them.
Rules
- Nothing is sorted or filtered by a commercial relationship. Lists are ordered by a certified figure, and the page says which one.
- No unit is added, removed, or reordered for payment. The set of units is the whole of the certified data.
- No certified number changes. Values are presented as published, never edited, and never invented.
- Which numbers are shown does not change. A page shows the same fields for every unit, including the ones that look bad.
- We do not rate, score, or rank manufacturers, and no payment would change that.
Advertising
No display advertising appears on this site: no banners, no interstitials, no sponsored rows in a table, no third-party ad script.
A page loads one stylesheet, one script, and the site's own fonts, all served from this domain. There is no third-party request on any page.
Affiliation and data sources
This site is not affiliated with, endorsed by, or certified by the U.S. Environmental Protection Agency, the U.S. Department of Energy, the ENERGY STAR program, or AHRI. Naming a program or a test procedure here identifies the origin of a number. It does not imply that its publisher has any involvement in this site.
The certified data comes from regulatory agencies. Certified figures are measured in a laboratory under the Department of Energy test procedure, certified by the manufacturer, and published in EPA's certified data. We present it as published. We do not adjust or estimate a certified value, and we never fill in one the certified data does not carry.
AHRI reference numbers appear because the certified data carries them: they identify a certificate, and a reader's quote usually carries one. Nothing on this site comes from the AHRI Directory.
Privacy
Looking up a model or postal area requests the data files needed to display the result; those file paths can appear in operational logs. Opening a link with a query string also sends that query to the delivery service.
We use Cloudflare traffic analytics for page views. Cloudflare delivers and protects the site and processes requests under its own service policies.
The site's own script reports two things to our server, to see which links and tools get used: when you click a link, the page you are on, the part of the page the link is in, and the address it points to; and when you use the quote check or the size calculator, whether it found a result. It never sends what you type, a query string, or an identifier, and it sets no cookie. These records and our server logs are kept for a short time.
Corrections
If a figure here disagrees with the certified data, that is our error. Send the page address and what you expected. We fix it.
We do not silently edit a certified value. If a page agrees with the certified data and you believe the certified data itself is wrong, the page says so and links the evidence, and the certified value stays as published.
Requests to add, remove, or reorder a model are not corrections, and they are declined.
Send corrections to [email protected].
The license on what we publish
The certified figures come from EPA's certified data, which is public-domain US government data. We claim no ownership of government data itself, and it remains available from EPA.
All rights are reserved in the text, charts, page design, software, derived statistics, and the selection and arrangement of the data. Quoting individual figures with a link to the page is welcome; bulk copying, republication, and machine-learning training are not. The terms of use set out both.
To ask for a data license, write to [email protected].
Some third-party notices survive all of this. NREL ResStock, Statistics Canada, the Open Government Licence - Canada, and the font licenses are below, in full. None of them lets us restrict the original material, and this page makes no attempt at it.
Data sources and licenses
The sources below supply the data shown on this site. Each entry explains what we use and includes its required license notice.
Certified performance
The EPA Energy Star list. Heating capacity at 5, 17, and 47°F, COP at 5°F, SEER2, EER2, HSPF2, cooling capacity, the cold-climate flag, the AHRI reference number, and every certified indoor pairing.
Certified performance figures from EPA's certified data (public domain, 17 U.S.C. §105). This project is not affiliated with or endorsed by EPA or the Energy Star program.
Test procedure and criteria
10 CFR part 430, subpart B, appendix M1, and 10 CFR 429.16. What each certified figure is, which test produces it, the compressor speed of each test, and the rounding grid for a declared capacity. Federal regulations, cited and not republished.
Energy Star Program Requirements for Central Air Conditioners and Heat Pumps, Version 6.1 and 6.2. The cold-climate criterion, and the requirement for the 5°F test that federal law leaves optional. A work of the US government.
Climate and geography, for the size calculator
NOAA NCEI Integrated Surface Database (ISD-Lite), US stations. Design temperatures, degree days, and temperature-bin hours at US stations.
Derived from NOAA NCEI Integrated Surface Database (ISD-Lite) hourly observations. Derived by this project, not by NOAA; NOAA does not endorse this site.
Hourly surface weather observations from the named stations, 2015 to 2024. The same statistics for Canadian postal codes, and for the US ZIP codes whose nearest suitable station is across the border. Each entry names the station it describes, with its identifier, position, elevation, and the years behind it, so any figure can be checked against the station that produced it.
U.S. Census Bureau geography. ZIP Code Tabulation Area positions, county names, and place names.
Geography from the U.S. Census Bureau. The Census Bureau is the source of the original data only; the estimates built from it are this project's.
USGS 3D Elevation Program. The elevation of each US area, which decides which weather station describes it.
Elevations from the USGS 3D Elevation Program (public domain).
PNNL-33270. The IECC climate zone of each US county.
County climate zones from Antonopoulos, C., T. Gilbride, E. Margiotta and C. Kaltreider. 2022. Guide to Determining Climate Zone by County: Building America and IECC 2021 Updates. PNNL-33270.
Field studies of home heating loads. The size calculator applies the displayed range for climate band and house condition to floor area. The field-study sources and observed ranges appear beside the estimate.
NREL ResStock. The modeled heating design load per square foot by climate zone and vintage appears as separate context. The calculator's default heating estimate uses the field-based range, not this modeled distribution. Its cooling estimate uses ResStock's modeled peak cooling load per square foot by climate zone and vintage.
Envelope defaults and cooling rates adapted from NREL ResStock (ResStock: Annual Baseline Results with Component Loads, DOI 10.25984/2001060), licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/); quantiles by climate zone and vintage computed here, so the figures are changed from the originals. The distribution is modeled, not measured.
Statistics Canada, 2021 Census Forward Sortation Area Boundary File. Canadian postal areas and the representative point of each.
Adapted from Statistics Canada, 2021 Census Forward Sortation Area Boundary File, 2021. This does not constitute an endorsement by Statistics Canada of this product. Includes information copied with permission from Canada Post Corporation.
Fuel energy content and equipment efficiency, for the size calculator
U.S. Energy Information Administration, Monthly Energy Review, Appendix A. The energy in a therm, a gallon, or a kilowatt-hour, for the calculator's optional estimate from fuel bills.
Source: U.S. Energy Information Administration (Aug 2026). Public domain; metric figures converted here.
U.S. Department of Energy heating equipment efficiency. The default efficiency for each kind of furnace or boiler, which the reader can change.
Building America Best Practices Series Volume 14, PNNL-20421, and the Federal Energy Management Program purchasing guides. Public domain information from the U.S. Department of Energy; DOE is acknowledged and does not endorse this site.
Canadian Digital Elevation Model, Natural Resources Canada. The elevation of each Canadian postal area, for the same station match.
Elevations from the Canadian Digital Elevation Model, Natural Resources Canada. Contains information licensed under the Open Government Licence - Canada.
Typefaces
Set in subsets of Source Sans 3 and Source Code Pro, © 2010–2020 Adobe, used under the SIL Open Font License 1.1. The subset files are renamed SrcSans3Subset and SrcCodeProSubset as that license requires. License text: Source Sans 3 · Source Code Pro.
Where the numbers are explained
The method in full · The dataset and its field definitions
- Source
- EPA's certified data
- Updated
- Oct 26, 2026
- Checked
- Daily, last difference found Oct 24, 2026
- Method
- Methodology