
Commercial HVAC Services on Long Island, NY
NJM provides reliable commercial HVAC installation, repair, and maintenance for businesses across Nassau and Suffolk County. We service office buildings, retail stores, restaurants, warehouses, and multi-unit properties — ensuring consistent comfort, energy efficiency, and long-term performance.
Professional Commercial HVAC Solutions Backed by 33+ Years of Experience
Commercial HVAC systems require the expertise of trained, licensed professionals who understand large-scale heating, cooling, and ventilation demands. NJM Mechanical and Contracting provides dependable service for rooftop units, commercial air conditioning, furnace systems, ductwork, and more.
Our team evaluates your building’s size, occupancy, and airflow needs to design and maintain systems that deliver consistent comfort and improved efficiency. Whether you need a new installation, emergency repairs, or long-term HVAC management, NJM ensures your business stays operational and comfortable year-round.

Installation of high-capacity heating and cooling systems tailored to your building’s size, airflow demands, and energy requirements.

Rapid diagnostics and repairs for rooftop units, split systems, furnaces, and commercial AC equipment to restore comfort quickly.

Preventive maintenance programs including coil cleaning, filter replacement, safety checks, and system optimization to reduce breakdowns and extend equipment life.

Installation, repair, and maintenance of commercial rooftop units — ideal for large spaces requiring high-efficiency heating and cooling.

Design, installation, and repair of commercial ductwork, exhaust systems, and ventilation to improve air quality and system efficiency.

Customized HVAC solutions for offices, retail stores, restaurants, and warehouses, ensuring optimal climate control across all seasons.

Expert Commercial HVAC Solutions
Backed by Over 33 Years of Experience
Why Businesses Choose NJM for Their HVAC Needs
With certified technicians and decades of hands-on experience, NJM delivers reliable and efficient cooling services for homes and commercial properties.
Professionals trained to handle complex commercial systems safely and accurately.
Quick troubleshooting and repairs to minimize downtime and maintain business operations.
We install high-efficiency heating and cooling systems designed to reduce energy expenses.
Tailored system design for offices, restaurants, warehouses, and multi-unit properties.
Serving Long Island since 1991 with proven reliability and technical expertise.
Upfront quotes, no hidden fees, and clear explanations for every service.
Electrical & Control System Inspection
Testing wiring, breakers, and control boards for safe, stable operation.
RTU Performance & Safety Testing
Inspecting rooftop units for proper burner/coil performance, ignition, and airflow.
Refrigerant Line & Pressure Testing
Ensuring correct refrigerant levels and checking for leaks.
Filter, Coil & Blower Review
Cleaning and inspecting components that impact efficiency and air quality.
Airflow & Duct System Evaluation
Reviewing ductwork, airflow balance, and ventilation efficiency.
Code Compliance & Commercial Safety Checks
Ensuring your system meets Long Island’s commercial HVAC safety and building standards.
Trusted Cooling Expertise for Long Island Homes & Businesses
Our Commercial HVAC Safety & Inspection Services Include:
NJM performs comprehensive inspections to ensure your commercial HVAC system operates safely, efficiently, and in full compliance with local codes.

Find Cooling Services Near You!
Service Area Links:
- Long Island
- Nassau County
- Suffolk County
What Our Long Island Clients Are Saying...
Kris
I couldn’t recommend Neil enough! From start to finish him and his team were professional, efficient and experienced. We had a job pulling up rocks and putting top soil down which I know can be a tedious job. We appreciate the work and look
Evelyn Powers
We had an ongoing issue with clogs. My daughter woke up to flooding in her bedroom from her toilet, which was not fun! This was our first time having NJM in our home. Neil was knowledgeable and gave us several options. we chose to have him use the camera to get to the root of the problem. He was able to pinpoint several issues and was able to fix clog and clean out the pipes. Neil and his crew were very professional,
Irene Cheung
I contacted NJM Mechanical because I didn’t have hot water anywhere in my house. Neil was able to diagnose the issue and get to work. My navien tankless water heater is only a year old and still under warranty. Instead of waiting on Navien to send the part so the issue can be corrected, Neil went out, found the part, purchased it,
William Lo
Great experience. Neil came out and took the time to explain everything thoroughly. He was able to fix all the errors on our Navien and have it back up and running. Following up a week later. Neil and Mike came out to redo the Navien system for proper instillation.
Unfortunatley, after there was a gas leak with our Navien system. Neil was able to get
James Farnworth
Neil from NJM was able to get my ac system up and running when others could not. He was honest with me right from the beginning and all costs were discussed before repairs began. Additionally, Neil spent time explaining to me how my system operates and the things I could do to help it run at peak performance. It was quite refreshing to experience a service technician who demonstrated the uppermost
Raul Chardon
Honest professional full of knowledge not BS. Takes pride in his craft and is a master of it.





