Commercial Applications

Multi-Story Building Exhaust2

Your exhaust runs 24/7. Your dryers don't.

Kitchens, baths and dryers in a vertical subdivision run less than 30% of the day — yet most building risers blast at full speed around the clock. Demand-controlled ventilation senses duct pressure and modulates the fan to match real demand.

 Fan power scales with the cube of speed — so idling near 14% reclaims almost all the energy a constant-speed fan burns.
The waste, plainly

One number runs the building. The other runs the bill.

<30%
of the day a typical dryer, hood or bath fan is actually in use.
MEANWHILE
100%
is the speed a constant-speed riser holds, all day, every day.

Every hour the fan spins flat-out with nothing running, it pumps heated or cooled air straight out of the building — air you already paid to condition. Why waste your energy? A demand-controlled riser turns that waste back into savings.

How demand control works

The duct tells the fan what to do.

No occupancy guesswork and no schedules to maintain — the system reads the pressure each appliance creates and answers it in real time.

STEP 01 · IDLE

Quiet by default

When no appliances are running, the fan holds at a very low trickle speed — just enough to keep the riser balanced, drawing almost no power.

STEP 02 · SENSE

Pressure rises

An appliance starts and its fan pushes air into the shared duct. Pressure climbs. A high-accuracy sensor catches the change within ±2% of set point.

STEP 03 · MODULATE

Fan answers demand

The controller's PID loop ramps the direct-drive, variable-speed fan up smoothly to hold exact pressure — then eases back down the moment demand falls.

Proven in the field

What customers have actually measured.

90%
Reduction in fan energy consumption
80%
Less spent on conditioned air being exhausted
$10K
Saved per duct riser — one sq ft per floor, 20-story building
±2%
Accuracy from set point vs ±20% in alternative solutions
Where it fits

Energy-saving, quiet spot exhaust — new build or retrofit.

Aesthetically clean, flexible and quiet solutions for virtually every vertical application. The system adjusts automatically to demand: no appliances running, it idles low; one starts, it answers.

Multi-story vertical subdivisions
Hotels & resorts
Sports arenas
Schools & colleges
Mixed-use towers
Central laundry facilities
Kitchen & bath exhaust
Retrofit risers
Trusted on the skyline

Behind some of the world's highest-profile buildings.

Dubai, UAE
Burj Khalifa Tower
Glendale, CA
Americana at Brand
Potomac, MD
Park Potomac Place
New York, NY
The Platinum
The systems

Two demand-controlled exhaust solutions.

Both sense duct pressure and modulate a direct-drive, variable-speed fan — purpose-built for the vertical risers of multi-story, multi-family and mixed-use buildings.

MBESr · Retrofit

Building Exhaust System

Modulating Retrofit Building Exhaust System

Built for existing risers serving multiple kitchen hoods, bathrooms or dryers across floors. Reuses ducts, fan connections and power already in place — most of the work is adding the controller and pressure sensing near the fan.

  • Ideal for occupied-building retrofits with minimal disruption
  • Variable-speed, direct-drive fan — no belts to break
  • ±2% pressure accuracy with PID-tuned control
MDVS · Central laundry

Mechanical Dryer Venting System

Demand-controlled exhaust for multi-story & central dryers

Designed specifically for buildings with clothes dryers on multiple floors or in a shared laundry. One fan can serve a whole riser, modulating with the load instead of running flat-out 24/7.

  • Spark-resistant, TEFC motor; listed for lint-laden air (UL705)
  • Diversity-based duct sizing frees floor space per riser
  • Roof discharge — no wall vents collecting lint and grime
Stop exhausting your budget

Turn 24/7 waste into measured savings.

Tell us about your risers and appliances. We'll model the conditioned-air and fan-energy savings for your specific building and climate.

ENERVEX
ENERVEX Inc.
1685 Bluegrass Lakes Parkway
Alpharetta, GA 30004, USA
Demand-controlled ventilation for heating appliances, dryers, kitchens & baths · 30+ years. MBESr · MDVS · Multi-Story Building Exhaust