This dataset identifies 163 patent families published between 2015 and mid-2026 that combine absorption chiller or absorption refrigeration terminology with control-system claim language, filtered to relevant IPC classes. That figure reflects a specific search scope, not every patent ever filed on absorption cooling generally — broader searches without the control-system filter would return a larger mechanical-refrigeration set. Filing families rather than raw documents gives a fairer count because it neutralises continuation filings and multi-jurisdiction duplicates of the same invention.

The corpus includes long-established refrigeration and energy-research organisations rather than a single dominant recent filer, and every tracked assignee shows zero filings in the most recent year. Rather than one company pulling ahead, activity is spread thinly and has been essentially flat since a 2022 midpoint of just two filings. Anyone assessing competitive position should look at cumulative family counts and citation influence together, not just the latest year's activity.

US20150345835A1, titled 'Refrigeration system with absorption cooling,' is the most-cited record in this corpus with 68 citations. Close behind are US6651443B1 on integrated absorption cogeneration and the much older US5477696A and US4164128A, both explicitly about absorption chiller control devices, showing that decades-old control concepts still draw significant citation volume. High citation counts here reflect influence within a searched corpus over time and should be read as a signal of historical importance rather than current commercial weight.

No — the filing trend across this dataset is flat to declining rather than growing, moving from zero filings in 2017 to a midpoint of two in 2022 and a peak of ten in 2024, with the most recent year showing zero. Because patent publication typically lags filing by around 18 months, the most recent year understates true activity, but even accounting for that lag there is no clear upward trajectory across the full window. This is a mature, low-volume filing area rather than one attracting a wave of new entrants.

The clearest gaps sit at the edges of the core F25B refrigeration classification: solar-assisted absorption control, wastewater-integrated absorption cooling, membrane-based separation pre-treatment, and vehicle-mounted absorption coupling controls each appear in only a handful of records. Dedicated control classifications like G05B and G05D are also thin relative to the mechanical refrigeration art, suggesting that control logic is frequently claimed as a system feature rather than protected as its own invention. A first claim in these branches would likely need to tie a specific sensing or sequencing method to one of these adjacent domains rather than restate general absorption-cycle control.