Top 5 Commercial Mechanical Contractors in Massachusetts
March 12th, 2025
4 min read

When you are building a large project, like a hospital, school, or office, it’s important to find the right mechanical contractor. These contractors install and maintain systems like heating, ventilation, air conditioning (HVAC), and plumbing. If these systems don’t work properly, it can cause a lot of problems, and fixing them can be expensive and time-consuming.
Choosing the best contractor for the job is key. You need a company that is reliable, experienced, and has worked on similar projects. Also, they need to finish the job on time and within your budget.
At Harold Brothers Mechanical, we know that choosing the right mechanical contractor can be overwhelming. Customers often ask us, 'If we don’t work with you, who should we choose?' The reality is, we aren’t the right fit for every project, and we believe in transparency when it comes to helping businesses find the best solution. That’s why we’ve researched and compiled a list of top mechanical contractors in Massachusetts, based on expertise, reliability, and industry reputation. In this article, we’ll break down our top picks and why they stand out. This guide will help you find the right contractor for your needs, whether you’re building a school, hospital, office building or any other commercial space.
The following are listed in alphabetical order:
Breen & Sullivan Mechanical Services: Full-Service HVAC & Electrical Experts
Breen & Sullivan provides both HVAC and electrical services, making them a good choice for healthcare and government buildings. They focus on safety and compliance with all the rules, ensuring projects run smoothly and meet high standards.
Why They're Great:
- Offers both HVAC and electrical services
- Works well with healthcare and government projects
- Focuses on safety and following all rules
Not Best For:
Small retail or restaurant HVAC jobs.
Small retail or restaurant HVAC jobs.Client Testimonial:
"Breen & Sullivan did excellent work for our hospital. They made sure everything was done safely and according to plan."
Hamel & McAlister, Inc.: Experts in Industrial HVAC & Ventilation
Hamel & McAlister specializes in industrial HVAC systems and ventilation. They have a lot of experience with large factories and plants that need complex HVAC systems. They know how to follow safety rules, making sure everything is up to code.
Why They're Great:
- Great for big industrial HVAC projects
- Pays close attention to safety and rules
- Strong experience in manufacturing and industrial projects
Not Best For:
Small office HVAC projects.
Client Testimonial:
"Hamel & McAlister are our go-to for industrial HVAC. Their work is always thorough and safe."
Harold Brothers Mechanical: Experts in HVAC & Plumbing for Large Projects
Harold Brothers Mechanical is known for handling big HVAC and plumbing jobs, especially in hospitals, life science labs, commercial buildings, schools, and sports facilities including ice rinks. They focus on making sure the systems are safe, high-quality, and up to code. They also use prefabrication, which helps lower costs and finish projects faster. This company reaches all across the Commonwealth of Massachusetts, into Southern NH and now Rhode Island. They also have a full Service Division who can customize a Preventative Maintenance Program for all your equipment needs.
Why They're Great:
- Specializes in hospitals, labs, commercial buildings, ice rinks and schools
- Uses prefabrication to save time and money
- Also provides Design Build and Design Assist when needed
- Good track record of finishing projects on time and within budget
Not Best For:
Small residential projects.
Client Testimonial:
"Harold Brothers always does great work, especially when it comes to following safety rules."
J.C. Cannistraro, LLC: Experts in Prefabrication & Fire Protection
J.C. Cannistraro is a top mechanical contractor known for prefabrication and fire protection. They have a special facility where they can build parts of the project ahead of time, making the process quicker and more efficient. They have worked on big projects like the Millennium Tower and other large scale buildings, showing their ability to take on large, important projects.
Why They're Great:
- Specializes in prefabrication to speed up projects
- Good at fire protection systems
- Known for safety and innovation
Not Best For:
Small projects without special needs like fire protection.
Client Testimonial:
"Cannistraro's prefabrication saved us weeks of work. Their fire safety systems are top-notch."
P.J. Kennedy & Sons: Trusted for Public Projects
P.J. Kennedy & Sons has been around for a long time and is trusted by schools and government buildings. They do a great job with public projects, and their workers are highly trained. They’re known for being reliable and making sure projects run smoothly.
Why They're Great:
- Experienced with public projects like schools and government buildings
- Skilled workers who get the job done well
- Great at staying organized
Not Best For:
Industrial or manufacturing HVAC projects.
Client Testimonial:
"P.J. Kennedy & Sons is always reliable when we need work done on public buildings. They never disappoint."
How to Choose the Right Mechanical Contractor for Your Project
Picking the right mechanical contractor is important for making sure your project is finished on time and within your budget. Here are a few things to consider when making your decision:
- Look at the Company’s Reputation: It’s a good idea to read reviews and ask for references from past clients.
- Check Their Experience: Make sure the company has worked on projects like yours. Some companies are better for schools, while others are experts in industrial buildings.
- Make Sure They Know the Rules: Contractors need to follow safety rules and building codes. Make sure they know what’s required for your project.
- Get Quotes: Ask for quotes from a few contractors. Compare prices and make sure the quote covers everything.
- Consider Prefabrication: If you need the project finished quickly, find a company that can do prefabrication, which can save time and money.
Comparison Table of the Top 5 Mechanical Contractors in Massachusetts
Company Name |
Specialization |
Best For |
Not Ideal For |
Harold Brothers Mechanical |
Large HVAC & plumbing projects, Prefabrication, Design Assist & Design Build |
Hospitals, labs, commercial buildings, schools, sport complexes |
Small residential projects |
J.C. Cannistraro, LLC |
Prefabrication, fire protection |
Large commercial properties, big projects |
Small, low-budget projects |
P.J. Kennedy & Sons |
Public projects like schools and government buildings |
Public buildings, schools |
Industrial HVAC projects |
Hamel & McAlister, Inc. |
Industrial HVAC & ventilation |
Large factories and industrial projects |
Small office HVAC jobs |
Breen & Sullivan Mechanical |
HVAC & electrical services |
Healthcare and government buildings |
Small retail or restaurant HVAC projects |
Where should you go from here?
Choosing the right mechanical contractor can make or break your project. To find the best company for your needs, think about the following:
- Experience: Make sure the contractor has worked on similar projects before and understands your building type.
- Reputation: Read reviews and talk to previous clients to learn about the company’s work quality.
- Capabilities: Check if they have the technology or special skills needed for your project, like prefabrication to speed things up.
- Price: Get quotes from several companies and compare them, but don’t just choose the cheapest option. Look for value, not just low cost.
By keeping these things in mind, you can find a mechanical contractor who will meet your needs and complete your project successfully. Whether you need HVAC, plumbing, or electrical work, one of these top contractors will help get the job done right. If you would like more information, please feel free to contact Harold Brothers directly. We are happy to help.
John Flaherty is the Senior Director of Business Development at Harold Brothers Mechanical, where he plays a key role in fostering client relationships and driving strategic growth. With nearly two decades of experience holding a real estate license, John brings a deep understanding of business development and market dynamics to his role. Before joining Harold Brothers, John dedicated 15 years to education administration at Boston College High School, where he helped shape institutional advancement efforts. A proud alumnus of BC High, he continues to serve on the school's Alumni Advisory Council, strengthening connections within the community. As a contributing author for Harold Brothers Mechanical, John leverages his diverse professional background to provide insightful articles on industry trends, business strategies, and company developments.
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