Zignego Company

The Zignego Group has completed urban, highway, and interstate construction projects across Wisconsin since 1954. For their operations in Pewaukee, Wisconsin, they needed a new repair facility that supported fleet maintenance and day-to-day work without disrupting ongoing yard activity. Timeline: April 2021 to September 2021. H&H Mechanical Contractors completed the HVAC and hydronic heating installation for Zignego’s new 27,700 sq. ft. repair facility.

Scope of Work

H&H Mechanical Contractors provided and installed:

H&H Mechanical provided and installed airside HVAC equipment, controls, and in-floor hydronic heating, including:

• 1 Carrier VAV RTU for office and production areas
• Associated supply and return ductwork for the RTU system
• 1 RTU roof curb
• Natural gas piping serving the RTU
• 10 VAV boxes in the office area for zoned airflow control
• Carrier BACnet i-Vu control system for the HVAC system across office and production
• All associated ductwork and controls for the VAV system
• 2 Lochinvar Knight boilers with all associated piping, pumps, air separator, valves, expansion tank, and inline filters
• PEX tubing for in-floor hydronic radiant heat, including manifolds

Results

This project included substantial completion and commissioning of an HVAC system combining a variable air volume (VAV) air distribution system with in-floor hydronic radiant heating serving the shop area.

VAV terminal units were installed as pressure-independent devices with airflow measurement stations, modulating dampers, and properly sized duct connections based on approved submittals and SMACNA standards. The air distribution system was configured to provide ventilation and cooling while allowing zone-level airflow changes based on space demand.

The in-floor hydronic heating system included insulated and pressure-tested PEX tubing embedded in the shop slab. Heating zones were routed through dedicated manifolds with balancing and isolation valves to help support even heat across the floor. Boilers, circulation pumps, expansion tanks, air separators, and safety components were installed and tied into the system to maintain stable temperatures and pressures. Hydronic circuits were flushed, purged, pressure tested, and balanced prior to startup.

Controls for the VAV system and radiant floor heating were integrated and commissioned to support coordinated operation between airside ventilation and slab-based heating. Final TAB and functional performance testing confirmed design airflow, hydronic flow rates, and temperature control requirements for reliable operation and consistent conditions throughout the shop area.

This new facility gives the Zignego team more repair bays for their equipment fleet and provides a collaborative workspace—without interrupting ongoing yard activity during construction.