The companies raised equipment prices more than 50% since then, the suit says, “greatly outpacing inflation as well as the rate at which other similar goods increased, despite historical data showing that these figures have largely moved in similar ranges.”

The complaint, filed April 30 in the U.S. District Court for the Eastern District of Michigan, is among at least four other similar lawsuits, the latest of which was filed April 20. The plaintiff seeks class-action status for “all other similarly situated persons and entities who directly purchased the above-listed Defendants’ HVAC Equipment” going back to at least January 2020.

Defendants in the case include Trane Technologies, Mitsubishi Electric Trane HVAC US (METUS), Lennox International Inc., Carrier Global Corp., Rheem Manufacturing Co., Daikin Comfort Technologies North America Inc., Robert Bosch, Johnson Controls-Hitachi Air Conditioning North America, and Aaon Inc.

The suit mentions the Air-Conditioning, Heating, and Refrigeration Institute (AHRI), charging the defendants used each others’ “non-public, confidential, and proprietary information” from AHRI to “strategize” price increases. The suit also says the defendants used The ACHR NEWS, which reports announcements of price increases, “as a platform to broadcast price increases and telegraph their intentions on pricing and supply.” Neither AHRI nor The NEWS are defendants in the suit.