Marine HVAC System Upgrade in 2025 – Armia Krajowa

Comprehensive marine HVAC system upgrade on MV Armia Krajowa

During a scheduled dry dock maintenance period at the shipyard in Varna, the Cold World engineering team carried out extensive installation and repair work. The main challenge we faced upon boarding was a severe condenser leak in the accommodation air conditioning unit. This critical incident became the direct catalyst for a complete marine HVAC system upgrade on the MV Armia Krajowa, encompassing a thorough replacement of key components across both primary refrigeration circuits.

Technical scope of shipyard modernization works

A properly planned marine HVAC system upgrade demands engineering precision and the use of certified marine-grade materials. Our team of technicians successfully executed the following tasks within the engine room and cargo spaces:

Accommodation AC: We dismantled the worn-out condensers and compressors. After preparing and welding new structural foundations, we installed modern shell-and-tube condensers manufactured by the renowned brand Bitzer (model K1353T). We fabricated new base plates for the compressors, performed precise system alignment, and installed new suction and discharge piping. Additionally, the refrigeration oil was replaced with Reniso Triton SEZ32, and new flexible capillary connections were routed for the control automation.
Provision Cold Room System: For operational efficiency and space optimization, the scope of work included the challenging relocation of evaporators in both the meat and fish cold rooms. Following the physical relocation of the units, we executed new hard-brazed copper pipe connections.
Air Handling Units (AHU): We conducted a full technical service and rigorous leak verification for the AHUs serving the Control Room, Galley, and Workshop. Across all liquid lines, the filter-drier cores were replaced with proven Danfoss DML 163 models.

Pressure testing, parameters, and system handover

Every professional marine HVAC system upgrade must conclude with strict quality assurance tests. Once the piping was assembled, a 24-hour leak test was performed using dry nitrogen under high pressure. Subsequently, a deep system evacuation was carried out down to a level of 500 microns to eliminate any residual moisture and non-condensable gases.

Ultimately, the systems were charged with eco-friendly R407C refrigerant (36 kg per primary circuit). The post-commissioning operational parameters, including a correct vapor superheat of 5 K and a condensing temperature of +37°C, confirmed full system efficiency. If your vessel is approaching a class renewal docking soon, discover our full capabilities in global marine service and major overhauls to guarantee expert support at every stage of your dry dock stay.