Business Details
50+ Years
experience
Emergency
services
Trusted HVAC and Roofing Solutions in Portland, Maine
Since 1914, W.H. Demmons has established itself as a leader in design-build-maintain engineering solutions, specializing in energy-efficient HVAC systems, geothermal technology, and commercial roofing. Our expertise spans over a century, combining historical craftsmanship with cutting-edge innovation to reduce client energy costs globally. With a merger in 1994 and the integration of Maine Air Conditioning, we expanded into HVAC innovation, completing New England's first geothermal building in the 1990s.Our team of certified engineers and technicians delivers customized solutions for residential, commercial, industrial, and marine sectors, supported by 24/7 monitoring systems and a commitment to continuous staff education. Recognized for excellence through awards like the Master Contractor Quality Award, we prioritize client satisfaction through precision, reliability, and proactive problem-solving, serving clients from Maine to California and beyond.
Services
HVAC Systems
Roofing
Sheet Metal Fabrication
Geothermal Engineering
Building Automation
Details
- Year established: 1914
Highlights and features
- We offer over 100 years of experience in HVAC and geothermal system design.
- Our team provides 24/7 system monitoring and emergency response services.
- We specialize in energy-efficient solutions for commercial and industrial clients.
- Our engineers hold certifications in building automation and process cooling.
- We maintain a proven safety record across global projects.
What people say
Proven innovative leader
Exceeded client expectations
Customized HVAC solutions
Energy-efficient designs
Expertise in geothermal systems
Services
HVAC Systems
W.H. Demmons designs, installs, and maintains customized HVAC systems for residential, commercial, and industrial clients. Our solutions include process cooling, refrigeration, and hydronic systems, supported by 24/7 monitoring to ensure optimal efficiency. With global experience since 1914, we deliver energy-efficient systems that reduce operational costs while maintaining precise environmental controls for sensitive applications like medical marijuana grow rooms.
Geothermal Engineering
Our geothermal HVAC systems leverage underground heat exchange for sustainable climate control. Pioneering this technology since the 1990s, we've completed New England's first geothermal buildings and continue to innovate energy-efficient solutions. These systems reduce utility costs by up to 60% while maintaining consistent indoor air quality, ideal for commercial facilities requiring stable temperature and humidity levels.
Commercial Roofing
Demmons Roofing provides durable, energy-efficient commercial roofing solutions using Duro-Last Cool Roof membranes and Firestone EPDM systems. Our services include same-day leak repairs, metal roofing installations, and UL-certified panel systems. With a history dating to 1914, we combine traditional craftsmanship with advanced equipment like the Schlebach Quadro+ forming machine to deliver long-lasting, cost-effective roofing for businesses in Maine and beyond.
Building Automation
We implement customized building automation systems using Reliable Controls technology. These systems monitor HVAC, lighting, and security from a centralized interface, enabling real-time adjustments and predictive maintenance. By integrating BACnet protocols and variable frequency drives, we optimize energy efficiency while preventing environmental fluctuations that could disrupt operations in critical facilities like laboratories and data centers.
Sheet Metal Fabrication
Our automated sheet metal shop produces ductwork, roofing components, and ventilation systems for HVAC applications. Using computerized machinery, we fabricate custom solutions for commercial kitchens, industrial facilities, and residential projects. This in-house capability ensures precise manufacturing, reducing lead times while maintaining compatibility with complex HVAC and ventilation requirements across diverse building types.
People
Douglas Martin
President
With 40+ years in HVAC engineering, Douglas Martin leads W.H. Demmons as President. Joining in 1986, he expanded the company's geothermal expertise and global reach. His leadership focuses on innovative solutions and client-centric problem-solving, maintaining the company's century-old commitment to excellence.
Jay Davis
Chief Executive Officer
Jay Davis oversees roofing operations with expertise in green roof design and emergency response logistics. With decades of experience, he specializes in complex roofing systems for commercial and residential clients, ensuring durable, energy-efficient installations that meet evolving industry standards.
Jeff Bard
HVAC Construction Manager
Jeff Bard manages HVAC construction projects with 17+ years at W.H. Demmons. Starting as a journeyman, he now coordinates large-scale installations and retrofits, combining technical knowledge with project management skills to deliver efficient, code-compliant systems tailored to client needs.
Dan Kosalski
Controls Manager
Dan Kosalski leads building automation initiatives, designing schematics and programming control systems. His expertise in electrical engineering and project management ensures seamless integration of HVAC, security, and energy management systems for commercial and industrial facilities.
Melissa Hall
Roofing Project Manager
Melissa Hall specializes in commercial roofing projects, combining technical precision with client communication. Recognized for leadership in complex installations, she ensures timely delivery of energy-efficient roofing solutions that meet structural and environmental requirements.
Questions
What HVAC services does W.H. Demmons offer?
We provide full-service HVAC solutions including design, installation, maintenance, and 24/7 monitoring. Our expertise covers cooling/heating systems, refrigeration, hydronic systems, and process cooling tailored to residential, commercial, and industrial needs.
Do you specialize in geothermal systems?
Yes, we pioneered geothermal HVAC systems in New England since the 1990s. Our engineers design and install energy-efficient geothermal solutions for commercial and industrial clients, reducing long-term energy costs.
What areas do you serve?
We operate throughout Maine, New Hampshire, and the Northeast, with projects spanning California, France, and Mexico. Our global monitoring systems support international clients.
Are emergency services available?
Yes, we offer 24/7 emergency HVAC and roofing services. Our monitoring systems detect issues immediately, allowing rapid technician dispatch to resolve critical problems like humidity control failures.
What roofing solutions do you provide?
We specialize in energy-efficient commercial roofing with Duro-Last Cool Roof and Firestone systems. Services include same-day leak repairs, UL-certified panels, and metal roofing installations using state-of-the-art equipment.
How do you ensure project quality?
Our team combines century-old craftsmanship with modern technology, including automated sheet metal fabrication and building automation systems. Continuous staff training and a proven safety record guarantee high-quality outcomes.
