H & D Mechanical, Llc
H & D Mechanical is a privately held, mid-size mechanical contractor in Upper Marlboro, Maryland, delivering HVAC, plumbing, sheet metal, medical gases, controls, and CADD/BIM coordination services to enterprise and government clients across healthcare, data center, commercial, defense, and transportation sectors in the greater Washington, D.C. metro area.
- Company typePrivate
- Founded2009
- HeadquartersUpper Marlboro, United States
- Headcount1–10
- GTM typeB2B
- OfferingServices
What H & D Mechanical, Llc does
H & D Mechanical, LLC is a privately held, mid-size mechanical contractor founded in 2009 and headquartered at 7703 Crain Highway in Upper Marlboro, Maryland. The company delivers HVAC, plumbing, sheet metal, medical gases, controls, balancing, commissioning assist, and facility management services, primarily to enterprise and government clients in the greater Washington, D.C. metro area. End markets include biotech and healthcare (Human Genomic Science, The Institute of Genomic Research, Southern Maryland Hospital, UM Prince George's Hospital Center), commercial and corporate (Amazon, Bank of America, Coca-Cola, KPMG), data centers (Equinix, Level 3, NASD, Savvis, UNISYS), entertainment and hospitality (MGM National Harbor), government and defense (U.S. Pentagon, U.S. Naval Academy, Fort Meade, Andrews AFB), and transportation infrastructure (BWI, Dulles, Reagan airports). Co-founders Sean Duffy and Erik Harley, supported since 2016 by VP of Estimating Jeff Kushner, anchor the leadership team with a combined 100+ years of industry experience, including prior ownership of Duffy Mechanical Corporation.
The company's underlying technology stack centers on an in-house CADD/BIM coordination department that produces 3D intelligent models, system coordination, and shop drawings using contemporary BIM software. This capability is offered as a distinct service line alongside preconstruction and design/build services and supports clash detection and real-time visualization across construction phases. Revenue is generated through project-based contracting on a custom, quote-driven basis tied to scope and complexity, with multi-year contract cadences typical for larger engagements. Marketing is largely relationship- and reputation-driven, supplemented by project bidding and a light social media presence.
The business is founder-owned, has no external funding, no parent company, no subsidiaries, no disclosed M&A activity, and no public awards or patents on record. Operational scope is regional rather than national, with no disclosed geographic expansion beyond the DC/Maryland/Virginia corridor.
H & D Mechanical, Llc firmographics
Firmographics- Name
- H & D Mechanical, Llc
- Legal name
- H & D Mechanical, LLC
- Website
- https://hdmechanical.net
- Company type
- Private
- Founded year
- 2009
- Operating status
- Operating
- Headcount range
- 1–10 employees
- Short description
- H & D Mechanical is a privately held, mid-size mechanical contractor in Upper Marlboro, Maryland, delivering HVAC, plumbing, sheet metal, medical gases, controls, and CADD/BIM coordination services to enterprise and government clients across healthcare, data center, commercial, defense, and transportation sectors in the greater Washington, D.C. metro area.
- Ownership category
- akta.pro rank
H & D Mechanical, Llc industry classification
Industry- Product category
- Mechanical Contracting Services
- NAICS
- Plumbing, Heating, and Air-Conditioning Contractors (238220)
- akta.pro industry
- HVAC & Refrigeration ContractingIndustrials, Manufacturing & Construction/Construction & Civil Engineering/Specialty Trade Contractors (MEP, HVAC, Plumbing, Electrical)HVAC Installation, Service & RepairIndustrials, Manufacturing & Construction/Industrial Services & Facility Operations/Building Maintenance & Repair (MEP/HVAC/Plumbing/Electrical)
Keywords
Where H & D Mechanical, Llc is headquartered
LocationHeadquarters
- HQ city
- Upper Marlboro
- HQ country
- United States
- HQ region
- North America
Offices1 record
Markets served
H & D Mechanical, Llc business model
Business model- GTM type
- B2B
- Offering type
- Services
- Cost components
- Personnel, Operations, Supply Chain, Technology or R&D, Marketing or Sales, Others
Revenue model
- Mechanical Construction Services: Project-based contracting revenue from mechanical construction services including HVAC, plumbing, sheet metal, medical gases, controls, and facility management. Services provided to healthcare, commercial, data center, entertainment, government, and transportation clients.
Pricing tiers
| Model | Billing | Price |
|---|---|---|
| Other | Multi-year contract | Custom project-based pricing |
Go-to-market motion1 record
Distribution channels1 record
Marketing channels3 records
H & D Mechanical, Llc product offering
Product offeringCore offering
H&D Mechanical provides comprehensive mechanical construction services for commercial, medical, scientific, and government facilities, covering HVAC (heating, ventilating & air conditioning), plumbing, sheet metal, medical gases, clean rooms, controls, balancing, commissioning assists, facility management, and value engineering. The firm also delivers preconstruction and design-build services and operates a dedicated CADD/BIM coordination department producing 3D modeling, system coordination, and shop drawings for project planning and execution.
Product overview
H&D Mechanical is a mid-size mechanical contractor providing a unified portfolio of mechanical construction services for the greater Washington, D.C. metro area. The company operates as a single-service business rather than a platform-plus-modules architecture, offering three interconnected service areas: (1) Mechanical Construction Services covering HVAC, plumbing, sheet metal, medical gases, controls, and facility management; (2) Preconstruction & Design Build Services for project planning and delivery; and (3) CADD/BIM Coordination Services providing 3D modeling and system coordination. The company serves diverse sectors including medical, scientific, commercial, data centers, entertainment, government, and transportation projects.
Differentiator
Problem solved
Functional benefit
Products and services
- Mechanical Construction Services Comprehensive mechanical construction services including HVAC (heating, ventilating & air conditioning), plumbing, sheet metal, medical gases, clean rooms, controls, balancing, commissioning assists, facility management, and value engineering for commercial, medical, and scientific projects in the Washington D.C. metro area.
- Preconstruction & Design Build Services Preconstruction and design/build services supporting project planning from initial stages through construction execution, including Design/Build, Design/Assist, Green Building & LEED Construction, Fast Track, Fixed Price, Lump Sum, and Procurement & Expediting Services for healthcare, commercial, data center, government, and transportation clients.
- CADD/BIM Coordination Services Full-range 3D modeling, system coordination, and shop drawing production using Building Information Modeling (BIM) technology. Generates 3D intelligent models for design, planning, and execution of all construction phases, with real-time updates to reflect changes or issues with other trades on the project.
Quantifiable outcome
- Duffy Mechanical grew into a multi-million dollar company handling complex projects at Prince William Hospital, Dulles and Baltimore Washington International Airports, and Ronald Reagan Office Building
Companies that use H & D Mechanical, Llc
Customer profileNamed customers21 records
Segments6 records
Ideal customer profiles5 records
H & D Mechanical, Llc technology and API
TechnologyTechnology focussed No
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature1 record
H & D Mechanical, Llc partnerships and signals
Strategic signalScale indicators2 records
Recent moves4 records
Expansion highlights4 records
H & D Mechanical, Llc competitors and assessment
Company assessmentBroad incumbents
- Comfort Systems USA: Large national mechanical and electrical contractor focused on HVAC, plumbing, and piping — comparable service lines but operates at significantly greater scale across many regions.
- Holder Construction: Atlanta-based national builder with strong Mid-Atlantic data center and mission-critical presence — relevant comparand for the data center vertical in which H&D operates.
- EMCOR Group: Largest publicly traded mechanical and electrical services firm in the US with deep federal/government and data center exposure — directly comparable vertical mix at much larger scale.
- APi Group: Public safety, specialty, and industrial services holding with mechanical services exposure — broader portfolio but competes for similar facility services and HVAC scope.
- Clark Construction Group: Major DC-area general contractor with extensive federal, healthcare, and commercial work — competes for overall project delivery where H&D operates as a mechanical subcontractor.
- Southland Industries: Privately held national mechanical contractor delivering HVAC, plumbing, and fire protection across commercial, healthcare, and mission-critical facilities — comparable service breadth, much larger footprint.
Direct peers
- Limbach Holdings: Public mechanical contractor providing HVAC, plumbing, and controls design, build, and service across commercial, healthcare, and institutional end markets — the closest public comparables on service mix and vertical exposure.
- IES Holdings: Public provider of electrical and mechanical infrastructure services for commercial, data center, and industrial customers — overlapping scope and similar commercial/government client profile.
Regional players
- M.C. Dean: Tysons, Virginia-based MEP and systems integrator with deep federal, intelligence community, and data center presence in the DC metro — directly comparable on geography, federal credentials, and data center vertical.
- Riddleberger Brothers: Mid-Atlantic mechanical contractor based in Virginia serving commercial, healthcare, education, and government clients — closest mid-sized regional peer in overlapping service lines and geography.
Market position
Strengths5 records
Weaknesses5 records
Competitive moat3 records
Key risks6 records
Key highlights7 records
Customer concentration
H & D Mechanical, Llc financial estimates
Financial estimateRevenue estimate
Valuation estimate
H & D Mechanical, Llc leadership team
Management profileNumber of profiles
Profiles3 records
H & D Mechanical, Llc funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
H & D Mechanical, Llc M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about H & D Mechanical, Llc
What does H & D Mechanical, Llc do?
H&D Mechanical provides comprehensive mechanical construction services for commercial, medical, scientific, and government facilities, covering HVAC (heating, ventilating & air conditioning), plumbing, sheet metal, medical gases, clean rooms, controls, balancing, commissioning assists, facility management, and value engineering. The firm also delivers preconstruction and design-build services and operates a dedicated CADD/BIM coordination department producing 3D modeling, system coordination, and shop drawings for project planning and execution.
Is H & D Mechanical, Llc a public or private company?
H & D Mechanical, Llc is a private company. It is classified as founder individual operated bootstrapped and is currently operating.
When was H & D Mechanical, Llc founded?
H & D Mechanical, Llc was founded in 2009. It employs 1 to 10 people.
Where is H & D Mechanical, Llc based?
H & D Mechanical, Llc is headquartered in Upper Marlboro, United States, in the North America region.
How does H & D Mechanical, Llc make money?
One revenue line is on record: mechanical Construction Services.
Who are H & D Mechanical, Llc's main competitors?
Broad incumbents on record are Comfort Systems USA, Holder Construction, EMCOR Group, APi Group, Clark Construction Group and Southland Industries. Direct peers are Limbach Holdings and IES Holdings. Regional players are M.C. Dean and Riddleberger Brothers.
Does H & D Mechanical, Llc have an API?
No public API is recorded for H & D Mechanical, Llc.
What industry is H & D Mechanical, Llc in?
H & D Mechanical, Llc's product category is Mechanical Contracting Services. Its primary akta.pro industry code is IMAFALAB, HVAC & Refrigeration Contracting, with a secondary code of IMAIABAA, HVAC Installation, Service & Repair. Its NAICS code is 238220.