NEW YORK, October 16, 2025 – Sentinel Capital Partners, a private equity firm that invests in promising midmarket companies, today announced the sale of NSI Industries’ HVAC division—which includes the market-leading Duro Dyne and Supco brands—to Lennox International for approximately $550 million in cash.
With this divestiture, NSI will refocus as a pure-play manufacturer of branded electrical products sold under iconic names like Bridgeport, Polaris, and Tork. Insulated connectors, fittings, and other high-value-add components with steady, replacement-driven demand will remain the core of NSI’s offering.
“There is an excellent strategic fit between NSI’s HVAC division and Lennox,” said John Van Sickle, a Sentinel partner. “This sale returns NSI to its roots as an electrical products company serving distributors nationwide. Our partnership with NSI’s talented management team builds on the company’s strong record of success, great brands, and reputation for superior service to electrical customers.”
“We’ve been proud to call NSI home for the past four years and look forward to joining the Lennox team in our next chapter of growth,” said NSI’s HVAC President, John MacQuarrie. “We remain focused on operational excellence, product innovation, and delivering exceptional value to our customers.”
Sentinel’s expertise in electrical manufacturing and distribution includes prior investments in ECM Industries (electrical products for construction, maintenance, lighting, irrigation, landscape supply, and gas utility markets) and Power Products (diversified electrical products). Sentinel’s broader industrial manufacturing and distribution expertise includes investments in Chromalox (commercial and industrial electric heating products and systems), Engineered Controls (specialized pressure regulators, valves, and other controls), LTI Boyd (engineered sealing and thermal management components), RotoMetrics (rotary tooling products), Sonny’s (conveyorized car wash systems and related products), and Spectrum Safety Solutions (fire detection and suppression products).