Annexair

Annexair manufactures high-performance, custom and semi-custom air handling units designed for commercial, institutional, and industrial HVAC applications. Their systems are engineered for flexibility, offering a wide range of configurations that support ventilation, energy recovery, humidity control, and indoor air quality requirements. What sets Annexair apart is its focus on efficiency, airtight construction, and advanced heat recovery technologies that help reduce energy consumption while maintaining reliable system performance. With strong engineering support and a commitment to quality manufacturing, Annexair delivers solutions built for long-term durability and consistent operation in demanding environments.

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The Experience Behind Every Recommendation

Behind every equipment solution is Havtech’s own established legacy of commercial HVAC expertise, driven by our decades of experience, extensive project history, and trusted industry relationships.

years in business

40 +

projects

500 +

partners

200 +

Comprehensive HVAC Offerings

Products That Fit Your Needs

Annexair delivers exceptional value through custom-built, highly efficient air handling systems engineered for long-term durability and maximum energy savings.

Thermo-composite Casing

The thermo-composite casing is a lightweight, corrosion-resistant, double-walled aluminum and foam-insulated air handling unit system with a true thermal-break, leak-proof welded construction that improves durability, reduces condensation, and is significantly lighter than conventional steel casings.

Package Cooling System

The Annexair Package Cooling System is an energy-efficient air-cooled or air-sourced heat pump solution that uses variable speed compressors and a wide range of capacities (5 to 300 tons) to optimize comfort while minimizing energy consumption.

Heat Exchanger

Annexair’s high-effectiveness coaxial tube-in-tube heat exchanger is a compact, anti-fouling design for water-source heat pumps that maximizes heat transfer through a multi-lead inner tube and counter-flow operation, with copper or cupro-nickel options depending on water conditions.

V3 Logic Smart Head Pressure Control

Annexair’s V3 Logic smart head pressure control uses variable speed Danfoss VZH compressors and PLC-driven control to precisely match load conditions, improving efficiency, reliability, and power factor while delivering up to 15–35% energy savings compared to conventional systems.

What You Get When You Work With Annexair & Havtech

When you work with Annexair and Havtech, you gain access to highly engineered air handling solutions supported by hands-on application and design expertise. Our team provides equipment selection support, design assistance, and application guidance to ensure each system is properly matched to the project’s performance and efficiency goals. We also support coordination between engineers, contractors, owners, and facility teams to streamline project execution and resolve challenges quickly. With local expertise across Maryland, Washington, D.C., and Pennsylvania, Havtech helps ensure Annexair systems deliver reliable, efficient performance from design through installation and beyond.

Product Categories

Air Handling Units

Custom & Modular AHUs

Dedicated Outdoor Air Systems

Water Source Heat Pumps

Applications and Industries

Designed for the Buildings You Work In

Annexair solutions are commonly used in healthcare facilities, schools and universities, government and public buildings, commercial offices, retail spaces, manufacturing plants, and hotels and resorts where efficient ventilation and indoor air quality are essential. Their air handling systems are designed to support both comfort and performance in environments that require reliable temperature control, filtration, and energy efficiency. Whether for new construction or system upgrades, Annexair helps deliver consistent, high-quality air handling for a wide range of building types.

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Proudly Representing Across the Region

Havtech partners with manufacturers to deliver innovative solutions across the Mid-Atlantic and beyond. With dedicated regional offices and expert teams, we bring industry-leading products and responsive support closer to you – wherever your projects take place.