MAKE-UP AIR UNIT REPLACEMENT

Rasmussen Mechanical Services replaced the flooded make-up air units at a precast concrete plant in Bellevue with new Hastings Model HRMUM indirect-fired gas units of matching capacity. Each new unit is a B model with an 80% furnace and a 409 stainless steel heat exchanger. Each also runs a single-speed TEFC motor on 460-volt, three-phase power with a fused disconnect. The units came with a make-up air control package, a fresh air intake hood with bird screen, 2-inch cleanable filters, an auxiliary starter contact and a low outlet temperature shut-off.

Matching the original equipment took some sorting out. The old units were built with 321 stainless heat exchangers, which Hastings no longer offers, so the new units moved to 409 stainless. The originals also used Modusnap valves that allowed discharge air setpoints up to 135 degrees, and that option has also been discontinued. Our mechanical crews set the new units and tied them into the existing system. Shoutout to our Bellevue installation team for the great work!

About US

Rasmussen Mechanical Services is a full-service mechanical contractor with over 55 years of experience supporting commercial and industrial facilities. Our teams work across a wide range of mechanical systems, providing the knowledge and field experience needed to complete projects of varying size and complexity.

Each project we take on is approached with careful planning, clear communication, and a focus on quality execution. Our crews are experienced working in active facilities, coordinating with other trades, and adapting to site-specific conditions to keep work moving efficiently and safely.

From initial coordination through project completion, Rasmussen Mechanical Services remains focused on delivering dependable results that support long-term system performance. This project reflects our ongoing commitment to practical solutions, skilled workmanship, and consistent execution across every job we perform.