Horizon Mechanical Services LLC

Horizon Mechanical Services LLC Air Conditioning Heating Refrigeration Division, a Black American-owned, minority-owned small business based in Upper Marlboro, Maryland, operates as a prime contractor providing HVAC and refrigeration maintenance, repair, and emergency response services to federal agencies exclusively under total small business set-asides. The company holds DOT-certified Disadvantaged Business Enterprise status and has been registered in SAM.gov since 2005.

Horizon's capability portfolio centers on preventive maintenance, emergency repair, and equipment replacement for HVAC systems, chillers, air handlers, environmental chambers, and small mechanical appliances at federal facilities. Representative work includes a $360,018.78 purchase order from the U.S. Geological Survey (awarded September 2026, running through September 2031) for HVAC preventive maintenance, routine repair, and 24-hour emergency services at the Gabrielson Lab facility in Laurel, Maryland—requiring Siemens automation software certification and a maximum two-hour emergency response time. Horizon also holds a $244,427.52 contract from the National Institute of Standards and Technology (awarded June 2025 through June 2028) for scheduled preventive maintenance and emergency repairs to a Vilter chiller, air handler unit AHU-15, and environmental chamber at NIST's Gaithersburg campus. A $165,745.44 NASA Shared Services Center purchase order (awarded October 2026 through August 2028) covers preventive maintenance and emergency repairs to 37 HVAC units, 46 Keurig coffee makers, 23 ice machines, and associated water heaters at NASA Headquarters in Upper Marlboro, with 24/7 four-hour emergency response availability.

Customer concentration tracks heavily toward research and technical agencies. The U.S. Geological Survey anchors the portfolio with a single award carrying $360 thousand in combined potential value; NIST accounts for two awards worth $298 thousand; and NASA, the Office of Naval Research, and the National Oceanic and Atmospheric Administration round out the active set. Eight distinct customer agencies have placed awards across the past five years, with the top five agencies (by potential value) representing 97 percent of combined potential value. All twelve awards in the source are prime contracts; Horizon does not subcontract on federal work.

Activity has remained modest but steady—one to three awards per year since 2022—with three awards (combined potential value $435 thousand) reaching ultimate completion within the next twenty-four months and therefore facing recompete. The combined potential value across all awards totals $959 thousand, with $353 thousand obligated to date (37 percent of the ceiling). Work is performed across multiple locations—Upper Marlboro and Gaithersburg, Maryland; Laurel, Maryland; Newport, North Carolina; Washington, DC; and Gaithersburg—with performance specifications typically requiring contractor presence during normal facility business hours and 24/7 emergency response capability.

Horizon Mechanical Services, LLC is classified as a small business according to the statutory requirements set forth in State Finance and Procurement Article Subsections 14-501 - 14-505, Annotated Code of Maryland and our company holds MBE certifications under MDOT and SWAM. Horizon Mechanical Services LLC is a commercial air conditioning, controls, and heating service establishment. We specialize in service, commissioning, new equipment startup, maintenance and repair of York and Trane centrifugal chillers, computer room air conditioning units, VRF systems, and 100% outside air systems.

Horizon holds pride in the fact that our clients are satisfied and we strive to resolve issues at hand as responsively and diligently as possible. VFD's building HVAC DDC controls and mechanical construction projects to include retrofitting of existing building mechanical systems.