Proclamations 11021 / 11032 · Annex III HVAC HTS · USITC Column 1 · As of Sep 18, 2026 · Scenario math, not invoices

Observed Section 232 rules changed mid-2026 for some residential HVAC codes; labeled scenarios show what that means for equipment duty math — not retail invoices. Proclamation 11021 generally imposed an additional 25% ad valorem Section 232 duty on certain aluminum/steel derivative articles (effective April 6, 2026). Proclamation 11032 then expanded the temporary 15% combined-ceiling treatment to agricultural equipment and certain HVAC systems and components predominantly for residential use (effective June 8, 2026 through December 31, 2027), listing codes such as 8415.82.01 and 8415.90.80 on Annex III. On an illustrative $5,550 residential changeout equipment BOM using MFN Column 1 rates, modeled total duty falls from about $1,491 under Column 1 + 25% to $832 under the Annex III 15% ceiling (modeled difference $658). This is a national scenario, not a CPI claim and not a state ranking.

Three findings reporters can use

Observed: Proclamation 11032 (91 FR 34085) adds certain predominantly residential HVAC systems/components to the temporarily-reduced 15% Section 232 treatment category, effective June 8, 2026 through December 31, 2027 (Annex III).
Observed: Before that expansion, Proclamation 11021 (91 FR 18201) set an additional 25% ad valorem duty on certain aluminum/steel derivatives (full customs value), effective April 6, 2026. Annex III / Annex IV / CBP CSMS describe a combined Column 1 + Section 232 ceiling of 15% when Column 1 is below 15%.
Modeled BOM: On a labeled $5,550 changeout equipment BOM (outdoor unit + coil + heat-pump parts) with MFN Column 1 rates, modeled duty is about $103 (Column 1 only), $1,491 (Column 1 + 25%), and $832 (Annex III 15% ceiling) — a modeled Annex III vs 25% difference of $658. Preferential Free Column 1 illustration: $1,388 vs $832.

Not a price-increase claim. We do not assert that tariffs caused an X% rise in contractor bids or retail equipment prices. We also do not rank states — import microdata are too weak for a clean state magnet. This page is about equipment duty scenarios, distinct from commercial electricity shop bills and fleet fuel costs.

Observed Section 232 schedule (primary sources)

Observed. Dates and rates below come from presidential proclamations published in the Federal Register, the White House Annex III list, and CBP CSMS guidance — not from trade-press alone.

Primary Section 232 references used in this study
Instrument	Cite	Effective	What we use
Proclamation 11021	91 FR 18201 (Apr 9, 2026)	Apr 6, 2026	Additional Section 232 duties on metal articles & certain derivatives; 25% additional ad valorem generally for certain aluminum/steel derivatives on full customs value
Proclamation 11032	91 FR 34085 (Jun 4, 2026)	Jun 8, 2026 – Dec 31, 2027	Expands temporarily-reduced 15% treatment to agricultural equipment and certain residential HVAC systems/components (Annex III)
Annex III PDF	White House (Jun 2026)	Same window	Lists HVAC HTS (e.g. 8415.10.60/90, 8415.81.01, 8415.82.01, 8415.90.80, 8516.29.00) and aluminum-side coil/parts suffixes
CBP CSMS #68855869	CBP guidance	Implements 11032	Chapter 99 headings 9903.82.01–9903.82.26 reporting instructions; combined-ceiling mechanics

Annex III combined-ceiling rule (as modeled): For covered articles, if the Column 1 duty rate is less than 15%, the sum of Column 1 + additional Section 232 duty totals 15% ad valorem. If Column 1 is 15% or higher, no additional Section 232 duty is due under the cited headings. Baseline derivative treatment outside that temporary reduction remains the 25% additional duty framework of Proclamation 11021 (subject to other exceptions in the proclamations). Always verify the current HTS Chapter 99 notes for a live entry.

Annex III HVAC-related HTS (observed list)

Extracted from the archived Annex III PDF. Column 1 general rates are from the USITC HTS search API (accessed 2026-09-18). Statistical suffixes inherit the parent 8-digit rate where USITC returns a blank child rate.

Annex III HVAC-related classifications + USITC Column 1 general rates
HTS	Description	Annex III list	Column 1 general
8415.10.60	Window/wall AC with refrigerating unit and reversible valve	steel derivatives	1.0%
8415.10.90	Window/wall AC, other	steel derivatives	2.2%
8415.81.01	Other AC with refrigerating unit and reversible valve (heat pumps)	steel derivatives	1.0%
8415.82.01	Other AC incorporating a refrigerating unit	steel derivatives	2.2%
8415.90.80	Parts of air-conditioning machines	steel derivatives	1.4%
8516.29.00	Electric space heating apparatus, other than storage heating radiators	steel derivatives	3.7%
8415.90.8010	AC evaporator coils, copper or copper alloys	aluminum derivatives	1.4%
8415.90.8020	AC evaporator coils, other	aluminum derivatives	1.4%
8415.90.8045	Parts of automotive AC machines	aluminum derivatives	1.4%
8415.90.8085	Parts of heat pumps for AC machines	aluminum derivatives	1.4%

Classification is fact-specific. Whether a particular outdoor unit, coil, or air handler is entered under these headings — and whether it qualifies as “predominantly for residential use” under the proclamation’s framing — is a customs question this page does not answer.

Residential changeout BOM scenarios

Method: Customs values below are documented author assumptions for editorial illustration — not invoices. Tables and figures are labeled HYPOTHETICAL. Duty $ = value × stated rate assumptions.

Assumed equipment lines (MFN Column 1)

HYPOTHETICAL BOM lines — modeled duty under three regimes (MFN Column 1 general rates)
Component	Modeled HTS	Col 1	Illustrative value	Col 1 only	Col 1 + 25% Sec 232	Annex III 15% combined	Modeled Δ (25% − 15%)
A. Outdoor unit (central AC / heat-pump outdoor)	8415.82.01	2.2%	$3,200	$70.40	$870.40	$480.00	$390.40
B. Indoor coil / evaporator assembly	8415.90.80	1.4%	$950	$13.30	$250.80	$142.50	$108.30
C. Heat-pump indoor / air-handler related parts package	8415.90.80	1.4%	$1,400	$19.60	$369.60	$210.00	$159.60
TOTAL	—	—	$5,550	$103.30	$1,490.80	$832.50	$658.30

Preferential Free Column 1 sensitivity (illustration only)

Many of these headings show Free under special rates for listed FTA partners. If Column 1 were Free on the same $5,550 BOM, modeled totals would be $1,387.50 under a 25% additional Section 232 additive vs $832.50 under the Annex III 15% ceiling (modeled difference $555.00). That is not a USMCA eligibility determination — origin, producer statements, and metal-content rules still apply.

Charts

Bar chart comparing hypothetical total modeled duty under Column 1 only, Column 1 plus 25 percent Section 232, and Annex III 15 percent combined ceiling for a 5550 dollar residential HVAC BOM — Figure 1. HYPOTHETICAL total modeled duty by regime (MFN Column 1; $5,550 BOM).

Grouped bar chart of hypothetical modeled duty dollars by outdoor unit, indoor coil, and heat-pump parts line under three duty regimes — Figure 2. HYPOTHETICAL duty $ by BOM line under three regimes.

Bar chart of modeled total duty as a percent of illustrative customs value under Column 1 only, Column 1 plus 25 percent, and Annex III 15 percent ceiling — Figure 3. Modeled effective duty rate comparison (before/after Annex III temporary reduction).

Bar chart of hypothetical Annex III modeled duty savings versus 25 percent derivative treatment under MFN and preferential Free Column 1 assumptions — Figure 4. HYPOTHETICAL Annex III vs 25% modeled duty difference (MFN vs Free Column 1 illustration).

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External demand context (no fabricated series): AHRI monthly shipments (subscription detail not integrated here).

Methodology and limits

What is observed vs modeled

Observed: proclamation text, Annex III HTS list, combined-ceiling mechanics, effective dates, USITC Column 1 general rates.
BOM values: documented assumptions.
Modeled: duty $ = value × stated rule. Not CBP liquidations.

Primary source URLs

What this page does / does not claim

Scenario ≠ observed contractor invoice or retail shelf price.
No claim that tariffs “caused” an X% price increase without a measured price series (we do not have one here).
Not legal, customs, classification, origin, or brokerage advice.
National scenarios only — not a fake state ranking.
Metal content, U.S. content, country of origin, and exact HTS can change Chapter 99 treatment.
AHRI shipment trends are linked for demand context only; no numeric AHRI series was integrated (subscription gate).

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Cite with a link to this page. Chart PNGs appear in the figures above.