Duncan Mechanical Services, Inc.

Duncan Mechanical Service, Inc., a small business based in San Angelo, Texas, provides HVAC chiller replacement, installation, and leasing services to the Department of the Air Force as a prime contractor exclusively under total small business set-asides. The company is a for-profit Subchapter S corporation registered in SAM.gov since 2002, competing across NAICS 453121 (Plumbing, Heating, and Air-Conditioning Contractors) and related equipment repair and maintenance categories.

Duncan Mechanical's federal footprint is concentrated almost entirely on a single customer and location. The Department of the Air Force Air Education and Training Command accounts for 20 of 29 prime awards (69% of the total portfolio) and $1.3 million in combined potential value — representing 93% of all awards by count and 99% of all dollars. All twenty AETC awards are directed at Goodfellow Air Force Base in Texas, where Duncan Mechanical has established itself as the primary vendor for the Air Force's chiller standardization initiative. That program encompasses 1,654 chiller units across eighty-seven installations through September 2029, with small business contractors historically representing 92% of participation. The General Services Administration Public Buildings Service holds four awards, and a third Air Force entity (likely a separate command or installation) holds three additional awards; neither of these customers carries material dollar value in the disclosed portfolio.

Representative work includes a $422,994 firm fixed-price contract awarded October 14, 2026, to remove a 250-ton air-cooled chiller and install a new 250-ton Trane chiller at Goodfellow with exterior chilled water piping, isolation valve, Y strainer, and aluminum-shielded insulation (ultimate completion January 13, 2027); a $147,289 purchase order awarded December 4, 2023, for an 80-ton chiller replacement at Building B222 (ultimate completion October 31, 2025); and a $121,308 purchase order for LIEBERT CRAC HVAC unit replacement at Building B530 (awarded July 26, 2022, ultimate completion July 25, 2023). Smaller contracts in the portfolio include chiller leases ($15,500 and $25,500) and equipment rental arrangements.

Activity contracted sharply after 2021 — six awards that year, but only three in 2022, one in 2023, and one in 2026 — reflecting either completion of an initial standardization phase or compressed procurement into fewer, larger orders. Only one award faces ultimate completion in the next twenty-four months ($423 thousand combined potential value). Duncan Mechanical operates exclusively as a prime contractor; no subcontract footprint appears in the source data. The vendor has obligated $1.7 million against $1.3 million in combined potential value, indicating invoiced work in excess of stated ceilings on multiple smaller tasks, a pattern consistent with firm fixed-price purchase orders that exceed initial estimates.