SumZero Energy Systems, LLC

4.92 |11 Verified Ratings
Write a Review

SumZero Energy Systems, LLC

4.92 | 11 Verified Ratings
Write a Review


84 October Hill Rd
Holliston, MA 01746
Your use of our services is governed by our Terms & Conditions

SumZero Energy Systems, LLC

Home Energy Improvement Experts

We are 'Home Energy Improvement Experts' focused on lowering the carbon footprint, while improving comfort, efficiency, and indoor air quality. The services we offer are HVAC design and installation, spray foam insulation, and energy auditing services. Our goal is to educate and provide solutions, based on building science principals, to homeowners and building professionals interested in any home improvement, remodel, or new construction project.


Learn how HomeAdvisor screens and approves their pros.

Service Area

  • Newton
  • Cambridge
  • Framingham
  • Waltham
  • Brookline
  • Watertown
  • Arlington
  • Wellesley
  • Southborough
  • Dedham
  • Lexington
  • Needham
  • Shrewsbury
  • Westborough
  • Woodville
  • Hudson
  • Marlborough
  • Arlington Heights
  • Blackstone
  • Hopedale
  • Franklin
  • Canton
  • Upton
  • Millville
  • Holliston
  • Wayland
  • Waban
  • Hopkinton
  • Lincoln
  • Milton
  • Natick
  • Medfield
  • Wellesley Hills
  • Nonantum
  • Bellingham
  • Wrentham
  • Ashland
  • Sharon
  • Dover
  • Medway
  • South Walpole
  • Sherborn
  • Maynard
  • Norfolk
  • Millis
  • Westwood
  • Weston
  • Milford
  • West Newton
  • Boston
  • West Roxbury
  • Fayville
  • Newton Highlands
  • Grafton
  • Auburndale
  • Norwood
  • Northborough
  • North Grafton
  • Newton Lower Falls
  • Sudbury
  • Mendon
  • Newton Upper Falls
  • South Grafton
  • Babson Park
  • East Walpole
  • Belmont
  • Chestnut Hill
  • Newton Center
  • Brookline Village
  • Needham Heights
  • See All >

Services Offered

Air Conditioning
  • Central A/C Install
  • Ductless Mini-split A/C Install
Heating & Furnace Systems
  • Heat Pump Install
  • Ductless Mini-split Heating - Install or Replace

Areas of Expertise

  • Air Conditioning & Heat Pump design & installation
  • Mini Split design & installation
  • Fresh Air Ventilation
  • Building Science

Product Brands Used

  • Mitsubishi
  • Bosch Thermotechnology

Quick Facts

Business Hours
8:00 AM to 5:00 PM
8:00 AM to 5:00 PM
8:00 AM to 5:00 PM
8:00 AM to 5:00 PM
8:00 AM to 5:00 PM
(Please call to confirm)
  • Free Estimates
  • Credit Cards Accepted
  • Bilingual


In Business Since: 2009
Memberships & Affiliations
  • Building Performance Institute (BPI) Certified Professional
State Licensing
Trade: Home Improvement Contractor
License #: 195250
Expiration: 04-16-2023
HomeAdvisor Screened. View Details

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To find more licensing information for your state, visit our Licensing Requirements page.

SumZero Energy Systems, LLC

My Work
1 Projects
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Ratings & Reviews
SumZero Energy Systems, LLC

Real feedback from real homeowners.
Learn more about this pro by reading the ratings and reviews below.
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Showing 1-10 of 11
  Page 1 of 2
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5.0   |  
Daniel Oliveira & Dan from SumZero Energy Systems arrived promptly, were knowledgeable and courteous. Upon explaining the issue with my AC fan, they immediately understood the problem and addressed it. They exceeded my expectations, explaining what went wrong and how to avoid this issue in the future. Even the initial telephone contact, setting up the appointment, communication, and addressing our specific needs were excellent. I highly recommend SumZero Energy Systems for all your HVAC needs.
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5.0   |  
Review by in Westborough, MA
Project: Install or Replace a Ductless Mini-split Air Conditioning System
Had a good experience. Communication was good - they patiently answered all our questions and even helped us with availing the MassSave rebate. The work was done in a day and they did a great job at it.
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5.0   |  
Review by in Medford, MA
Very clean, efficient workers. Answered all questions and were very pleasant to work with
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5.0   |  
Review by in Worcester, MA
Project: Install or Replace a Ductless Mini-split Air Conditioning System
Dave Sampaio and the team were very reliable regarding project scheduling and execution. Efficient, clean, polite they were satisfying all my requests regarding particularities of the job. I am pleased to recommend SumZero to anybody that wants to hire them.
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5.0   |  
David Sampaio from SumZero was one of six contractors we interviewed for central AC replacement. David was very helpful in our decision making process when we were deciding between AC and heat pump units. His price was very reasonable too. We chose the heat pump in the end and are very happy with the choice. David’s team was very polite and professional during installation, they did an excellent job setting everything up and cleaning the area. High five, David! Thank you!
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5.0   |  
Review by in Medway, MA
This company is professional in every way. From David coming over my house to give me the estimate, to the people working, they were so polite. David is so pleasant, he talked to me about everything that would happen the day of the installation, and he was true to his word in every way... Plus His price was the best by far compare to the other companies appraisal. My recommendation? Go with SumZero. You'll be 100% satisfied!! Thank You David and company for the perfect work and price. I could not be happier! Grace Macaluso.
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5.0   |  
Review by in Natick, MA
They are a professional; respectable, and knowledgeable crew. I'm very impressed by their commitment to do a good job. I would hire them again if needed.
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5.0   |  
Review by in Ashland, MA
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5.0   |  
SumZero Energy Systems have been excellent in the last several months with supporting the replacement of my air conditioning system in my old condo as well as servicing my furnace. A price comparison with other local companies also prooved SumZero Energy Systems offered the best price. When I purchased a home a few months later, I called them to take a look at my air conditioning system and furnace because I felt as though they had provided such excellent service in the past. It was a no-brainer to ask for consultation regarding the heating and cooling systems in my new home! When I contacted them for assistance or consultation, they are usually quick to respond and provide appointment times had a very convenient window! They have shown up on time to all of the appointments I have had. David S. has always taken the time to explain everything thoroughly and answer all my questions. I highly recommend SumZero Energy Systems!
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5.0   |  
Review by in Roslindale, MA
The A/C that was installed was actually a ductless A/C from Mitsubishi . It has the ability to heat as well. My experience with SumZero and Ilija and his crew was top notch. They were wonderful to work with. Professional, polite and very efficient. I d definitely use them again and have recommended them to numberous people.
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Showing 1-10 of 11
  Page 1 of 2

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