In commercial kitchens and labs, the Make-Up Air (MUA) system is essential for pressure balance. If the MUA fails, the exhaust hoods will pull “negative pressure,” making doors hard to open and causing kitchen heat to spill into the dining area.
Blower Motors and Belt-Drive Maintenance
As a specialist in Commercial HVAC Repair, I analyze MUA systems starting at the blower assembly. We check for belt slippage and motor amperage. If the unit has a gas-fired heat section (common in Seattle winters), we troubleshoot the Direct Spark Ignition (DSI) module and the air pressure switch. If the switch doesn’t “prove” airflow, the gas valve will never open for safety.
Why is my restaurant door hard to open and whistling?
This is a classic sign of negative building pressure caused by a failed Make-Up Air system. Either the blower motor has failed, the drive belt has snapped, or the intake filters are 100% blocked, preventing fresh air from entering the building.
Facility Air Balance Experts
Restore your building’s pressure and safety with professional MUA service.
- Call: (425) 535-8990
- Service: Same-Day Commercial HVAC Repair Seattle