Customized HVAC Maintenance Agreements Tailored To Your Company’s Unique Needs

Donnelly Mechanical provides customized HVAC preventive maintenance agreements for a distinguished clientele including many of New York City’s prestigious buildings, institutions and tenants. Our goal is to ensure peak operating efficiency, minimize equipment downtime and eliminate the need for repeat service calls. 

Our dedicated maintenance staff has the experience you can count on when you need to replace your HVAC vendor. During the transition process, our team familiarizes themselves with your facilities’ entire HVAC system. At the first maintenance inspection, we conduct a comprehensive analysis of all existing equipment and provide proactive solutions to avoid major failures and mitigate risk.

Commercial Preventive Maintenance not only extends the life of your equipment, but saves you money, giving you a better return on your investment. Performing regular maintenance on your Commercial HVAC system also increases energy efficiency.We understand how important it is to manage your budget, and that’s why we’ve been serving clients for over 30 years as their trusted provider for Commercial HVAC Preventive Maintenance in New York City.

HVAC Maintenance

The Donnelly Difference

Comprehensive Assessment of Existing Equipment

24/7 Emergency HVAC Repair Service and Support

Unique NYC Zoning System To Ensure Prompt Response

100+ Vehicles and 30+ Stationary Technicians

Account-Dedicated Technicians

Online Client Portal to Place Service Requests

Contract Transition Team

Priority Support

Quality Control

Watch Here to Learn More About Our Preventive Maintenance Offering

Benefits of Commercial HVAC Preventive Maintenance

Reduced Operating Costs

Routine maintenance will reduce your operating costs by keeping your system running smoothly, increasing energy efficiency, and reducing mechanical breakdowns and service costs.


An HVAC maintenance agreement means performing routine maintenance and being proactive to help mitigate any potential issues your system might face before it happens.

Optimized Indoor Comfort

Your space or building will feel more comfortable with a system that is running efficiently. This means more consistent temperatures and airflow.

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. Immediately after Sandy, Donnelly came in and demolished the submerged units, removed them and started to rebuild them so we could be up and running. We were the first building lit on generator power after the storm. Donnelly was there when we needed them most. Donnelly’s there when we just need them. We all work really well together.


The Donnelly Client Portal

Service Requests are as easy as one-two-three

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

A convenient, centralized place to manage their maintenance requests and records, the Donnelly Client Portal maintains a comprehensive record of all preventive 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 Preventive HVAC Maintenance service provider.

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Commercial HVAC

Fast Response and a Worry-Free Resolution

(718) 886-1500