Air Conditioning Installation & Replacements on Long Island, NY
NJM provides professional air conditioning installation and replacement services designed to keep your home or business cool and comfortable. We install central air systems, high-efficiency AC units, and ductless mini-splits backed by 33+ years of HVAC experience across Nassau and Suffolk County.
Central Air • Mini-Splits • Energy-Efficient Cooling Systems
Reliable, Energy-Efficient AC Installation Backed by Decades of Experience
Whether you're replacing an outdated AC system or installing a new cooling solution, NJM Mechanical and Contracting delivers clean, precise, and code-compliant installations tailored to your property. Our licensed HVAC specialists install central air conditioning, ductless mini-splits, and high-efficiency systems that improve comfort, reduce energy usage, and provide long-term reliability.
We evaluate your home’s layout, insulation, and cooling requirements to recommend the best AC system for your needs — always installed with expert craftsmanship and full transparency.
Installation of new, energy-efficient AC systems designed for consistent cooling, improved airflow, and reduced energy costs.
Replace outdated or unreliable air conditioners with modern, high-performance systems that deliver better comfort and efficiency.
Professional installation of whole-home central air conditioning systems, including ductwork evaluation, unit sizing, and optimized airflow design.
Perfect for homes without ductwork, additions, or individual room control — mini-splits offer quiet, efficient, and flexible cooling.
Expert Cooling Solutions Backed
Backed by Over 33 Years of Experience
Why Choose NJM for Air Conditioning Installation?
With certified technicians and decades of hands-on experience, NJM delivers reliable and efficient cooling services for homes and commercial properties.
Professionally trained to install all major AC system types safely and accurately.
We offer energy-saving systems designed to lower monthly utility costs.
We ensure your AC system is properly sized for your home to improve comfort and prevent unnecessary strain.
All installations follow Long Island HVAC safety and building standards.
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 Check
Inspection of wiring, breakers, disconnects, and thermostats for safe operation.
Condenser & Coil Performance Check
Testing condenser units and evaporator coils for efficient heat transfer.
Refrigerant Line & Pressure Testing
Ensuring lines are properly connected, sealed, and pressurized.
Drainage & Condensate Line Inspection
Ensuring proper drainage to prevent leaks and water damage.
Airflow & Duct Evaluation
Reviewing duct design, airflow levels, and system balance for efficient cooling.
Long Island Code Compliance Review
Verifying system installation meets Nassau and Suffolk County HVAC regulations.
Trusted Cooling Expertise for Long Island Homes & Businesses
Our AC Installation Safety & Inspection Services Include:
To ensure safe and efficient cooling, NJM performs detailed inspections before and after installing your new AC system.
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.