"The work that we're doing is saving lives, it's creating opportunity that's really important to us to continue on," Su said. "We are not backing down."

The Labor Department has been active in issuing new rules this year, including expansions to overtime pay eligibility, updates to the test for classifying workers as contractors, and protections for farmworkers on temporary visas. While these rules have attracted legal challenges, Su believes they are "squarely within our authority within the law."

The Supreme Court's elimination of Chevron deference, which required courts to defer to agencies' interpretations of unclear laws, may change the landscape for these challenges. However, Su expressed confidence in the Department's ability to withstand legal tests under the new precedent.

Regarding overtime rules, which raised the bar for the overtime exemption, the reception from HVAC contractors has been mixed, said Kate Wessels, vice president of communications, marketing, and partnerships at the Air Conditioning Contractors of America (ACCA).

“Many contractors have expressed concern about the increased operational costs and the additional burden of having to make changes to comply with the new regulations,” Wessels told ACHR NEWS in June. “Smaller contractors, in particular, are worried about the impact on their profitability and the potential need to pass on some of these costs to customers, which could affect their competitiveness.”

"It is worth knowing that the agencies that deal with workplace, such as the Department of Labor, very much do reflect the political philosophy of whoever's occupying the White House,” Duncan added, alluding to the next general election taking place Nov. 5.

As the DOL presses on with its agenda, and the election looms nearer, expect close scrutiny on how both courts and agencies apply the new standard.