How Four Star Mechanical Became a National Leader in VRF and Mission-Critical HVAC Solutions

Mission Critical

​Just minutes from Four Star Mechanical’s shop is a major facility operated by a global leader in aerospace maintenance, repair, and overhaul (MRO) services. The company specializes in engine and component repair, airframe services, avionics, and engineering support for both fixed-wing and rotary aircraft. Since opening in 2007, the site has experienced steady growth, including the addition of a 206,000-square-foot expansion to its original 236,000-square-foot floor plan.

In 2024, the facility’s leadership contacted Four Star with concerns about overheating in their main electrical room — a critical 2,500-square-foot space housing four transformers and extensive switchgear. Four Star’s team investigated the issue and discovered that rising cooling loads, driven by increased production demands, had outpaced the room’s original cross-ventilation system.

Over a multi-month data logging period, Steve Martin tracked internal temperatures consistently exceeding 100° F, with peaks as high as 116° F — far above the customer’s target. To address this, Four Star designed and installed a dedicated cooling system using Fujitsu AIRSTAGE V-series VRF equipment, providing 32 tons of cooling capacity.

In May 2024, Four Star technicians completed the project in under two weeks, installing four, one-to-one, eight-ton VRF systems with high-static air handlers and rooftop condensing units. This approach not only doubled the required cooling capacity but also ensured full system redundancy — an essential safeguard in the high-stakes aerospace environment, where downtime can severely impact operations.

To further enhance reliability, the new systems were integrated with the facility’s Building Management System (BMS) for remote monitoring. Since the upgrade, the average temperature at the transformer inlet has dropped significantly, improving operational safety and reliability.