Preventive Maintenance HVAC Service Customized to Your Needs

Commercial HVAC Service with a Facilities Management Focus

Donnelly Mechanical provides custom HVAC preventive maintenance service for a distinguished clientele within many of New York City’s prestigious buildings and institutions.

Our goal is to ensure efficient and continued operations of all your HVAC systems, including server room air conditioners, for the ongoing comfort for your tenants and uninterrupted operation of mission critical systems. Our hands-on approach allows us to be easily accessible when you need us most and ensures your peace of mind.

How Donnelly Mechanical Benefits You:



We understand the difficulty of changing maintenance vendors. During this process, our team familiarizes themselves with your facility’s entire HVAC system. This ensures consistent, cost-effective service at every point of contact thereafter while integrating your site into our Service Division.


Security is an important facilities concern. Donnelly provides you with a dedicated team of technicians who will develop an intimate understanding of your system and provide you with the personalized technical support and information you require.


We conduct inspections to enhance and improve our valued clients comfort experience. In addition to our regular maintenance inspections, we review sites annually from a different viewpoint to ensure that we are providing the best possible service both today and tomorrow.


Whenever you need an immediate resolution to a problem, the Donnelly executive team is available to help you.

HVAC Technician

Donnelly Client Portal Makes Service Requests Easy As 1, 2, 3

No more service request emails or phone calls required.

Client Portal

To expedite the service scheduling process, Donnelly clients are now able to make and review service requests simply by logging on to their Donnelly Client Portal from their desktop or mobile device!

As Simple As 1, 2, 3

A convenient, central place to manage their maintenance needs and records, the Donnelly Client Portal maintains a comprehensive record of all maintenance services.

Always focused on providing our distinguished clientele with best-in-class service, the easy-to-use Donnelly Client Portal is one more benefit of choosing Donnelly Mechanical as your Preventative HVAC Maintenance service provider.

Are you an existing Maintenance Client?

Register Today!

Accounts are typically activated within two business days and login credentials are emailed directly to you.

Donnelly Mechanical commercial HVAC service technicians working on a Carrier HVAC unit in a New York City building.
Every year we bring Donnelly in to do a full diagnostic survey of all the equipment and then we make adjustments. Since the relationship started in 2002, we have not had a machine down.
– Building Manager, 17 State Street, Manhattan

John Fallon

Need more info?

Contact your hands-on Project Owner now!


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

Fast response and a worry-free resolution – that’s The Donnelly Difference.