Positive Pressure Rebalance

Our TAB services team was called out to a Dairy Farmers Of America facility to help solve a pressure issue. When we received the call, the facilities roof was bubbling in spots and bay doors were bowing outward and being pulled off the rails. This had forced the facility to replace the roof twice in a single year and to purchase all new bay doors. When our team arrived, they took pressure readings at each door and compared them to the original design specifications. They then surveyed the make-up air units and exhaust fans in the facility. After measuring the rooms they served they calculated the air changes per hour required using the formula ACPH = (CFM x 60) / AREA. Our team was able to identify that some of the make-up air units were providing almost double the amount of air needed. They also found that multiple exhaust fans had loose or broken belts. This combination of excess air being pushed into the building and not enough air being expelled lead to the positive pressure that bowed doors and bubbled the roof. Our team got to work adjusting each make-up air units to, meet and slightly exceed, the minimums needed to pass all certifications. They then repaired all broken exhaust systems. The adjustments to the make-up air units reduce energy use by as much 50% in some cases and will allow for a quick payback period on the work completed (not to mention the roof replacement and door replacement that will no longer be needed).

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.