Commercial Products  > Commercial Systems
Building Exhaust System X

The ENERVEX Modulating Building Exhaust System™ (MBESx) is a demand-controlled ventilation system designed for multi-story buildings with multiple kitchen hoods, bathrooms or clothes dryers on multiple floors.

Rather than having a large number of individual exhaust ducts for each appliance, or a fan that operates at full speed 24/7, the MBESx senses when appliances are running and modulates with the load. It assures proper exhaust rates at any time no matter the demand. Can reduce the exhaust rate of conditioned air by up to 60-70%. In addition the BEFx fan is ultra-efficient with high-efficiency housing design and a IE5 highly-efficient EC-motor.

The MBESx system consists of a BEFx Exhaust Fan and an MEC 24 Constant Pressure Controller with an XTP Pressure Transducer. The system uses an EC-motor and an MSC EDrive E3 Motor Speed Controller.

The MEC 24 control modulates the speed of the BEFx ventilator based on the ventilation demands of the building to maintain the set-point during normal operation. The MBESx ensures the set-point is reached within 30 seconds of system start-up and is maintained with a tolerance of 0.01” W.C.

When a number of clothes dryer, kitchen or bathroom exhausts are connected into a common duct, the MBESx will modulate with the load. Once an appliance starts up, the pressure will change in the common duct and the MBESx will react by increasing speed and vice versa.

During normal operation, ramp-up and ramp-down time of the fan will be no more than 20 seconds. In the case of a mechanical or electrical failure, the control goes into alarm and sets the ventilator to run at 100% speed. If connected, the alarm signal will be sent to the Building Management System.

  • Automatically controls fan speed based on current demand
  • Costs less to operate than a fixed-speed CAV system
  • Extremely suitable for retrofitting
  • Discharges inline or on the roof, making it easier to clean architectural vents
  • Quiet performance eliminates constant fan noise & noise from speed variations
  • Ability to combine ducts & reduce duct sizes cuts material & labor costs
  • Variable speed, direct-drive fans eliminate broken belts
  • Costs 55% less to operate than a fixed-speed CAV system
  • Saves up to 85% of the cost of exhausted conditioned air
  • Unused air can save $500 per kitchen hood & $200 per bathroom annually
MBESx Building Exhaust System X—demand-controlled ventilation system with box fan and modulating pressure control
BEFx Box Fan—variable-volume centrifugal exhaust box fan with a capacity of more than 6,000 CFM
Box Fan

Multi-use, high performing, variable-volume centrifugal exhaust box fan designed for indoor and outdoor installation. Can be used for special exhaust or exhaust of lint-laden air or to supply make-up air and combustion air.

MEC 24 Modulating Pressure Control—simple modulating fan control for multi-story applications
Modulating Pressure Control (multi-story)

A modulating pressure control that provides superior pressure control in single- or multi-story building applications such as clothes dryers, bathrooms and kitchens.