AI Overviews for HVAC Searches: Who Gets Cited and Why

The base rate moves around more than most owners assume. Semrush's study of 10M+ keywords found AI Overviews triggered on 6.49% of queries in January 2025, 24.61% in July, and 15.69% by November — rapid growth, a pullback, and a settling point around one in six queries. The same study found the keywords that trigger AI Overviews tend to be longer and more specific than those that don't, and nearly 60% of them have 100 or fewer monthly searches. That is long-tail question territory — exactly where HVAC troubleshooting content lives.

Repair questions vs hiring searches

Intent decides trigger odds more than topic does. Semrush tracked the intent mix of AIO-triggering queries across 2025, and the direction matters for HVAC owners:

*Commercial, transactional, and navigational baselines are from October 2024 in Semrush's data. Source: Semrush AI Overviews Study, December 2025 refresh.

Read that table as composition, not probability: it says most AI Overviews still sit on informational queries, while commercial and transactional queries make up a fast-growing share. For HVAC, the practical split looks like this: "why is my furnace short cycling" and "how much does a heat pump cost to run" are the profile that triggers AI Overviews. "Emergency AC repair near me" still mostly resolves to the local pack and ads — Semrush found the industries with the fewest AI Overviews (Real Estate, Shopping, both under 3% of keywords) are precisely the ones that lean on local intent, because searchers there need maps, reviews, and action buttons that a text summary can't provide. That reasoning is Semrush's; applying it to emergency HVAC service queries is our read, and it matches what we see in live SERPs. Whether those AI answers cost contractors clicks is a separate question with evidence on both sides — we lay out the click-loss evidence, both ways in a dedicated piece.

Trigger rates swing — treat any snapshot as dated

The trigger share nearly quadrupled between January and July 2025, then gave a third of it back by November. Semrush's quarterly view shows the same churn at domain level: Q2 2025 brought an explosion of AI Overviews across industries, Q3 pulled back — over half of sectors saw fewer of their keywords trigger one — and Q4 grew again, with AIOs finishing the year 155% more present among top domains' keyword rankings than in Q1 on average. Two practical consequences for an HVAC owner: a competitor's citation today is not permanent, and any report that treats one month's AI Overview data as a stable baseline is over-reading it. Re-check your target queries quarterly; the surface underneath them moves.

What our own SERP pull shows

Our live DataForSEO pull for "ai overviews hvac" (US, desktop, August 13, 2026) returned an AI Overview above the first organic result — and all four People Also Ask questions on that SERP expanded into AI-generated answers rather than classic snippets. One query is an observation, not a dataset: we are building the full HVAC query panel now. [OWNER: run the ~25-query HVAC SERP panel (emergency repair / cost / troubleshooting / hiring query types, ≥3 pulls each) to generate the trigger-rate chart data for this page's build-time image.]

Filtered to standard blue links only, Ahrefs' distribution looks like this:

Source: Ahrefs, "38% of AI Overview Citations Pull From The Top 10", March 2026.

Why ranking #1 no longer guarantees a citation

The mechanism behind that drift is documented by Google itself: both AI Overviews and AI Mode may use a query fan-out technique — splitting the search into multiple related sub-queries and pulling supporting pages from those sub-query results. A page that never ranks for "AC blowing warm air" can earn the citation because it ranks for the fan-out question "why is my AC compressor not turning on." Ahrefs' interpretation is that fan-out sourcing expanded as Google moved AI Overviews onto newer Gemini models (Gemini 3 as of January 2026, per its report).

For an HVAC contractor site, fan-out sourcing rewrites which pages carry the citation load. Your service page competes on the original SERP for "AC repair [city]"; the pages retrievable across the fan-out sub-queries are the answers wrapped around that job — what the repair costs, what causes the failure, when replacement beats repair, how long the fix takes. A site that is one service page deep has one lottery ticket per query. A site with a genuine troubleshooting and cost library holds a ticket in every sub-query drawing that sources the same AI Overview.

One honesty note before you rebuild your strategy around any single number: overlap figures disagree sharply by methodology. Search Engine Journal's coverage of the Ahrefs update notes that BrightEdge's February 2026 analysis found about 17% top-10 overlap, while BrightEdge's own October 2025 figure was 54% — different datasets, different parsing, different answers. The direction every study agrees on: rank alone predicts citations less than it used to.

The YouTube wildcard

Among cited pages that didn't rank in Google's top 100 for the query, 18.2% were YouTube URLs in Ahrefs' data — and YouTube accounted for 5.6% of all AI Overview citations in the dataset, making it the most-cited domain Ahrefs tracks in AI Overviews. For an HVAC company, that means a competitor's five-minute "how to unclog a condensate drain line" video can earn the citation on a troubleshooting SERP where your service page ranks and still goes unmentioned.

Google's own guidance points the same direction without promising anything: its documented best practices for AI features include making important content available in textual form, supported by quality images and video, with structured data that matches the visible text. No special AI markup exists — the doc is explicit that there are no additional technical requirements beyond normal Search eligibility.

Structurally, an HVAC page shaped like the cited patterns has:

• A two-sentence direct answer at the top, before any brand copy
• One question per H2, answered in the first sentence beneath it
• Numbered diagnostic or decision steps instead of advice buried in paragraphs
• Figures only where a source backs them — a real price range, a spec, a measured time
• An original photo, diagram, or video of the actual work, never stock imagery

The SERP furniture around AI Overviews reinforces the question-and-answer shape. Semrush found People Also Ask co-occurs on 90.03% of AIO SERPs and related searches on 95.32% — these are question-dense results pages. For an HVAC site, the format lesson is concrete: a troubleshooting page that opens with a two-sentence answer, walks through numbered diagnostic steps, and embeds an original photo or video of the actual repair is shaped like the content AI Overviews cite. A page of adjective-heavy service copy ("trusted comfort specialists serving the metro area") gives the system nothing to extract.

Under the hood the two are siblings: Google's documentation says both may use query fan-out, though they can run different models and surface different links for the same question. The difference that matters to an HVAC owner is what kind of question each one absorbs. AI Overviews sit on the quick factual questions. AI Mode is built for the multi-constraint research a replacement buyer actually does — "heat pump vs high-efficiency furnace for a 2,200 sq ft house with $0.14/kWh electric" — the conversation that used to take six searches and three tabs. Google also announced agentic capabilities for AI Mode that will complete tasks for the searcher, starting with event tickets, restaurant reservations, and local appointments — a category worth watching for anyone whose business runs on booked appointments.

Google's own numbers say these surfaces grow usage rather than cannibalize it — its internal data claims AI Overviews drove over 10% more Google usage for the query types that show them in the US and India. That is Google measuring Google, so hold it loosely. We compare the two surfaces in depth, homeowner behavior included, in AI Mode vs traditional search for home services.

1. Clear the only documented gate. Google's sole stated technical requirement: the page must be indexed and eligible to show in Search with a snippet. No blocked crawling, no nosnippet, no noindex. Boring, and disqualifying more HVAC sites than anything on this list.
2. Rank somewhere retrievable. The top 10 is no longer sufficient, but it is still the single largest citation bucket at 37.10% in Ahrefs' organic-only data — and another 26.20% of citations come from positions 11–100. Ranking nowhere in the top 100 leaves you competing for the remaining slice against every page on the web.
3. Cover the fan-out questions, not just the keyword. Since Google confirms query fan-out, a page that answers the adjacent sub-questions — cost, cause, DIY-vs-pro, timeline — is retrievable on more of the sub-query SERPs that source citations.
4. Shape pages for extraction. Direct answer up top, numbered steps, sourced figures, original images: the formats named in the pattern evidence above.
5. Put a presence on YouTube. With YouTube as the most-cited domain in Ahrefs' AI Overview data, an original repair or install video is a second lottery ticket on SERPs where your page doesn't rank.
6. Measure honestly. Search Console reports AI Overview and AI Mode clicks inside the regular Web search type, not as a separate line — so track citations directly with periodic manual or tool-based SERP checks on your target queries.

One caution that doubles as a buying filter: AI Overview output is probabilistic. Ahrefs notes that content, citations, entities, and fan-outs change with every query run. Anyone selling guaranteed AI Overview placement is selling certainty that the surface itself doesn't offer. What can honestly be sold is the work above — eligibility, coverage, format, measurement — plus a documented baseline and quarterly re-measurement, because as the volatility data earlier shows, a citation held in March can be gone by June through no fault of the page. That evidence-first program is exactly what our AI-search visibility service runs for HVAC companies.