Dunn, who progressed through a series of senior roles during more than two decades at Toshiba, said the decision reflects a desire to return to the customer-facing work that shaped the early part of his career.

He said: “After 23 years of moving up the corporate ladder, I found I was moving further and further away from the customer. So I decided to move back to my roots to enable me more time to spend with customers, and working again with Darrel was a big draw as we have skill sets that complement each other.”

His appointment strengthens CDL’s leadership as the business continues to grow its offer in cooling and heat pump design. Dunn’s long experience in the UK air conditioning market, combined with Birkett’s existing technical and commercial remit, is expected to support the company’s plans to expand its work with contractors, consultants and end-users.