One of the Best Service Companies in the United States

The Donnelly Difference

When you choose to employ Donnelly Mechanical for your HVAC and energy service needs, you’re aligning with one of the best service companies in the United States – this is the Donnelly Difference.From our technicians and project managers to the executive team, all employees are certified by some of the nation’s most recognized professional contracting organizations. We also ensure we are in full compliance with all federal and local regulations, sometimes even surpassing requirements formulated by these standards. Whatever your HVAC or energy concern, you can rest assured that your Donnelly team will handle it with the utmost care and confidence.

Our expert team is comprised of 140 industry professionals and 95 skilled craftsmen, including senior-level staff with LEED-accreditation from the U.S. Green Building Council. We can meet WBE requirements for the City and State of New York as well as the Port Authority of New York/New Jersey. We’re one of the select MSCA Green Star contractors in the USA and our headquarters recently received ENERGY STAR certification from the U.S. Department of Energy.


The Mechanical Service Contractors of America (MSCA) is the nation’s leading trade association representing the heating, ventilation, air conditioning and refrigeration (HVACR) service contractors. MSCA STAR is an achievement designation for service excellence awarded to an elite group of mechanical service contractors. As an MSCA STAR certified company, we have demonstrated we offer commercial business and facilities clients unsurpassed support, quality workmanship and safe, reliable service.


Our entire team goes through rigorous OSHA training to ensure prevention of safety and health hazards on and off the job.

Need more information? Call Donnelly Mechanical at (718) 886-1500 today.

Celebrating Over 30 Years of Outstanding Service