Business Details
17 Years
experience
Trusted Mechanical Contracting Services in Maryland
Founded in 2009 by Sean Duffy and Erik Harley, H & D Mechanical is a mid-sized mechanical contracting firm headquartered in Upper Marlboro, Maryland. Our expertise spans medical, scientific, and commercial projects, where we prioritize creating safe, efficient, and durable environments for clients. With decades of combined industry experience, we deliver high-quality work that enhances building functionality and client value. Our commitment to innovation is reflected in our adoption of cutting-edge BIM technology for precise project execution. We serve the greater Washington, D.C. metro area, focusing on strategic growth and client satisfaction.Our teams dedication to excellence has established us as a trusted partner in complex construction projects. We emphasize workforce development through training programs, ensuring our staff remains at the forefront of industry standards. Our track record includes work on hospitals, airports, and government buildings, underscoring our ability to meet rigorous demands. Transparency, collaboration, and accountability form the foundation of our client relationships. By integrating advanced technology with traditional craftsmanship, we consistently exceed expectations in every project phase.
Services
HVAC Installation
Plumbing Systems
BIM Coordination
Medical Gas Piping
Design-Build Services
Facility Management
Details
- Year established: 2009
Highlights and features
- We specialize in complex mechanical systems for medical and commercial facilities.
- Our team uses advanced BIM technology for precise project execution.
- Decades of leadership experience in plumbing, HVAC, and construction management.
- Proven track record with high-profile projects like airports and hospitals.
- Commitment to workforce development through ongoing training and mentorship.
Services
HVAC Installation
We design and install heating, ventilation, and air conditioning systems tailored to commercial and medical facilities. Our solutions prioritize energy efficiency, regulatory compliance, and long-term reliability. Clients benefit from reduced operational costs and optimal indoor climate control.
BIM Coordination
Our BIM coordination services create intelligent 3D models for construction projects. This technology enables real-time visualization, clash detection, and cost-effective project management. Clients gain improved accuracy and collaboration across all construction phases.
Plumbing Systems
We provide comprehensive plumbing solutions for new construction and retrofit projects. Our work meets strict code requirements while ensuring durability and functionality. Services include piping, drainage, and specialized systems for healthcare facilities.
Medical Gas Piping
We install medical gas systems compliant with NFPA 99 standards. Our expertise ensures safe, reliable oxygen, vacuum, and anesthesia systems for hospitals and clinics. Precision and adherence to regulations are our top priorities.
Design-Build Services
We offer end-to-end design-build solutions that streamline project delivery. By combining design and construction under one team, we reduce costs, accelerate timelines, and ensure alignment with client goals.
People
Sean Duffy
Co-Founder & Owner
Sean Duffy co-founded H & D Mechanical after 25+ years in the industry. He holds a Business Administration degree from Marist College and completed a 5-year plumbing apprenticeship. He previously led Duffy Mechanical Corporation to multi-million-dollar success.
Erik Harley
Co-Founder & Owner
Erik Harley brings 20+ years of management experience to H & D Mechanical. He studied computer science at the University of Maryland and previously co-managed Duffy Mechanicals operations. He founded RGB Plumbing before rejoining Sean in 2009.
Jeff Kushner
Vice President of Estimating
Jeff Kushner oversees estimating and preconstruction services with 35+ years in mechanical contracting. He joined H&D in 2016, specializing in design-build projects and cost management for complex commercial and institutional facilities.
Questions
What types of projects does H&D Mechanical specialize in?
We focus on mechanical systems for medical facilities, commercial buildings, and scientific institutions, including HVAC, plumbing, and medical gas piping.
Do you serve areas outside Washington, D.C.?
We primarily serve the Washington, D.C. metro area, including Maryland and Northern Virginia.
How does H&D Mechanical use BIM technology?
We employ BIM for 3D modeling, clash detection, and real-time project visualization to improve accuracy and reduce costs.
Can you handle large-scale construction projects?
Yes, our team has experience with complex projects at airports, hospitals, and government buildings like the Ronald Reagan Office Building.
What certifications do your technicians hold?
Our team includes union-certified plumbers and HVAC specialists with ongoing training in the latest industry standards.
How do you ensure project quality and compliance?
We follow strict quality control protocols, including code inspections and collaboration with engineers to meet all regulatory requirements.
