Foodservice Equipment Reports

PRODUCT GALLERY: Demand-Control Ventilation


Vari-Flow integrated kitchen ventilation systems modulate exhaust and supply airflows to match cooking demands. Temperature sensors located in the hoods’ ACCUREXcapture area respond quickly to load changes. This feature, coupled with a fan-speed turndown of 50% and high efficiency Vari-Green motors, offers total energy savings in terms of electrical, heating and cooling costs. Use the keypad or new advanced touchscreen control with independent light and fan control, programmable fan scheduling, help diagnostics and energy-usage monitoring in live/historical modes for trending and programming. The Vari-Flow system is compatible with BACnet MSTP/IP, LON and ModBus to easily integrate the system into a range of building management systems.


Avtec will have a heat-only system ready the second quarter of 2013 that will useAVTEC hood-mounted sensors and a control panel to operate the fan at 80% of capacity unless more is needed. The programming finds the most economical way to match the exhaust rate to the heat generated. Auto-start sensors to meet IMC-2006 requirements are standard. Melink systems supplied by Avtec also come standard with programming to accommodate IMC-2006 and combine temp and optical sensors to give a greater energy-savings range across the entire cooking cycle. When cooking starts, the fans operate nominally 40% to 50%; as the heat increases the fan will speed up to 100% as needed.


Caddy Smart Hood works in conjunction with variable speed fans throughCaddy Corp. temperature sensors and algorithms to calculate fan speeds based on the equipment used and cooking loads. During low-volume times, fans will run at minimum set points based on equipment, codes and environmental considerations. During peak periods, fans increase as dictated by exhaust temperature. The system is controlled and monitored through a touchscreen where a multitude of options are available, such as UV hood control, real-time and automatic weekly scheduling. 


The Energy Management System provides the right combination of performance, Captiveairefeatures and price, according to the company. The first-generation system monitors temperature at the duct and modulates exhaust fan-speed and supply air up and down to suit. Now, EMS Plus adds a touchscreen interface for better setup and diagnostics, monitoring and building integration as well as sensors to measure ambient room temperature. The differential between ambient and hood temps is what dictates fan response. Diverse appliances create different peaks and valleys in the hood temp, and tracking the difference between hood and ambient temperature is a comprehensive and reliable gauge. 


Gaylord’s DCV system is custom programmed to accurately read and react in real time with faster and more flexible thermal sensors inside the hood canopy, featuring one ambient temperature sensor per exhaust fan. From there, the emphasis is put on extensively customizable algorithms to match local climate, individual pieces of cooking equipment and operating profiles. Additional benefits include a longer life on your HVAC systems and reduced hood noise, creating a more productive kitchen. DCV is competitively priced, fits into any manufacturer’s hood and qualifies for rebates and incentives in select states.


GEH’s variable air volume (VAV) hood detects smoke and heat, increasing and decreasing exhaust volume as needed. The TEL kitchen control system has microprocessor-based controls; the sensors automatically regulate fan speed based on cooking load, time of day and hood temp to minimize energy use. The TEL system includes a temp sensor installed in the exhaust collar, sensors that detect smoke/steam and variable frequency drives (VFD) that control the speed of the fans. Soft-starting hood fans with a VFD extends belt life. Reducing the outside air load on the kitchen’s HVAC units reduces compressor run time while extending its life. 


Halton’s M.A.R.V.E.L. demand control ventilation (DCV) system uses infraredHalton sensors to measure cooking surface temperatures—not just temps in the hood—to achieve a fast response time to cooking changes. Sensors aimed at the appliance surfaces work with a temp sensor (in the duct collar) and a room-temp sensor to determine cooking status. System can independently control multiple hoods on a common duct and fan, a unique feature. With the use of automated balancing dampers and direct exhaust airflow readings, the system ensures the appropriate amount of exhaust for each hood. If the design requires multiple hoods on a single fan, the system can balance them automatically. 


Measuring temperature, steam and smoke in the hood, Intelli-Hood adjusts fanMelink speed accordingly to save fan energy and conditioned air. While many demand control ventilation (DCV) systems run at 80% minimum speed, Intelli-Hood operates at a minimum speed of 10% to 50%. During actual cooking, the speed increases as needed up to 100% until smoke and vapors are removed, keeping the ambient temp comfortable. With its plug-and-play system, Intelli-Hood kitchen ventilation systems are scalable to any size project; one keypad can control up to 8 hoods. A support network of trained techs is available 24/7.


Truflow demand control ventilation can be integrated into the building management computer using LON, BacNET or Modbus protocols. Truflow features a large touchscreen display that shows real-time energy savings for program optimization. One Truflow controller can control up to 5 separate exhaust fans with makeup air fans independently of each other. For systems with multiple hoods on a common exhaust, a Zoneflow variable-volume damper can be added to balance the system and accurately control air volume to each hood. 


DemandAire variable-frequency motor-control system can handle from 1 to 4Streivor variable-frequency drives powering motors ranging from 1/3 to 5 hp with 208/230V, 3-phase motors. DemandAire receives continuous data from the temperature sensors located in the exhaust hood or duct and makes real-time adjustments to the exhaust- and supply-fan motors. DemandAire soft-starts motors at 80% power and automatically maintains that level until cooking begins, triggering a high-temp signal for 100% power (or until the operator activates the 100% power override switch). The 20% reduction in power translates to 48% reduction in energy use.

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GALLERY: Commercial Kitchen Ventilation

SPECIAL REPORT: Ventilation Gallery