HVAC System Repair
IMEG, under its joint-venture with PRIME AE, provided field investigation and engineering design services to replace the HVAC system along with the necessary electrical workin dorm Building 20351 at Kirtland AFB, New Mexico. The project scope was to replace all chillers, boilers, pumps, exhaust fans, two-pipe fan coil units, and piping related to the existing HVAC system.
The three-story airmans’ dormitory, built in the 1950s, has gone through several renditions of the HVAC system. Due to the age of the facility and the HVAC system, maintenance and upkeep of this system was a constant battle. The exhaust fans, chillers and fan coil units were old and in poor condition. The piping did not have water treatment for several years and caused issues with the fan coils units and pumps due to sediment composed of rust and metal shards. The fan coil units developed sediment blockages due to the poor conditions of the pipes and the pumps had to be repaired/replaced twice a year from the metal shards tearing up their seals. The boilers were near the end of their lifespan.
The design of the HVAC system replaced all chillers, boilers, pumps, exhaust fans, two-pipe fan coil units, and piping related to the existing HVAC system. The HVAC system is used to heat and cool all areas of Dormitory 20351 and includes new ductwork including grilles, louvers, and diffusers as needed. The existing controls were replaced and new direct digital controls and remote monitoring for the HVAC system were provided. The design complies with all DoD energy conservation measures. A life cycle cost analysis has been conducted comparing three different system types over a 40-year study period.
The electrical work included adding a 480 volt electrical distribution system with a 1000 KVA-480Y/277 volt oil filled transformer connected to an exterior mounted 1600 amp, 480 volt switchboard. All new mechanical equipment connects to this switchboard. The transformer/switchboard addition was sized to serve future tenants that require a power quality electrical service. The existing 208Y/120 volt electrical distribution system is 26 years old and requires removal in a few years. The new 480 volt distribution system replaces the 208 volt system with dry-type transformers/208V panelboards. The new switchboard and all panelboards contain electronic trip circuit breakers, SPDs and PQMs. The ground electrode system was replaced and enhanced with XIT-type ground rods. A master ground bar was established where all dry type transformers and telecom boards were referenced from the master ground bar.
New smoke detectors in the AHUs were interconnected with the existing fire alarm panel as required. Automatic and pushbutton HVAC system shutdown were incorporated into the design. Based on HVAC re-design, fire sprinklers needed to be relocated to accommodate changes in ductwork, diffusers, etc. A new direct digital control and remote monitoring are compatible with KAFB System.