Demand Ventilation Control Systemsfor

Commercial Kitchens

NEBB

February 24, 2012

Presented By:Mike Dean

What is DVC for CKV?

Demand Ventilation Controls for Commercial Kitchen Ventilation

True “demand ventilation” control system designed specifically for commercial kitchens.

A controls package that can be “retro-fitted” to a commercial kitchen exhaust hood, or designed into a “new construction” application.

Controls the grease exhaust and make-up air unit fan motors for each exhaust hood system.

VFD’s modulate exhaust fans based on a controlled input, exhaust air temperature, and make-up air fans are then controlled proportional to exhaust.

History Traditional kitchen ventilation systems have been controlled

by basic electro-mechanical interlocks for years.

NFPA 96 required grease exhaust duct velocities of 1,500-2,500 fpm up until 2002. This forced mechanical engineers into constant volume designs for many years

January 2002 NFPA issued Errata 96-01-01 changing Section 8.2.1.1 to read “ The air velocity through any duct shall be not less than 152.4 m/min (500 ft/min)”

History

This single revision allowed the traditional constant volume kitchen ventilation system to enter into the world of variable volume

2004 first Melink Intelli-Hood system installed in California

Energy conservation became trendy…..and…..more openly subsidized

History

UC/CSU/CCC Campuses

ASHRAE 90.1/189.1 CEC PIER Technology

Codes/StandardsASHRAE 90.1-2010 Section 6.5.7.1 Kitchen Exhaust Systems

6.5.7.1.41. If a kitchen/dining facility has a total kitchen exhaust airflow rate

greater than 5,000 cfm then it shall have one of the following:

a) At least 50% of all replacement air is transfer air that would otherwise be exhausted.

b) Demand ventilation system(s) on at least 75% of the exhaust air. Such systems shall be capable of at least 50% reduction in exhaust and replacement air system airflow rates, including controls necessary to modulate airflow in response to appliance operation and to maintain full capture and containment of smoke, effluent and combustion products during cooking and idle.

c) Listed energy recovery devices with a sensible heat recovery effectiveness of not less than 40% on at least 50% of the total exhaust airflow

Codes/StandardsASHRAE 189.1-2009 Standard for the Design of High-Performance Green Buildings Except Low-Rise Residential Buildings 

7.4.3.9 Variable-Speed Fan Control for Commercial Kitchen Hoods.

In addition to the requirements in Section 6.5.7.1 of ANSI/ASHRAE/IESNA Standard 90.1, commercial kitchen Type I and Type II hood systems shall have variable-speed control for exhaust and make-up air fans to reduce hood airflow rates at least 50% during those times when cooking is not occurring and the coking appliances are up to temperature in a standby, ready-to-cook mode.

All exceptions in Section 6.5.7.1 of ANSI/ASHRAE/IESNA Standard 90.1 shall apply.

Why is this important? Changes to Standards, and Codes, show a growing trend towards the adoption of the technology across the board

Now What?

Melink Intelli-Hood(OEM by: Greenheck, AccurexKees, Gaylord)

CaptiveAire EMSplus

Spring Air TruFlow

Halton MARVEL

PG&E Food Service Technology Center

Allen BradleyPowerFlexor ABB ACH550Series VFD’s

Intelli-HoodI/O Processor

InterfaceKeypad

Temperature Sensor

Air Purge Unit

Infrared Optic Sensor

Keypad Mounted At Pull-Station

Optic Sensors Mounted Inside Hood Canopy

Variable Frequency Drives The heart of variable volume controls

Melink Intelli-Hood Video

So, now we have a new demand ventilation control system. How do we incorporate existing HVAC systems and proper air balance

Commercial Kitchens and Restaurants are typically very “leaky” facilities and present different air balance challenges:

Diner’s entering and exiting the main doors Competing ventilation systems. i.e. Dining area air conditioning Versus kitchen

ventilation (and now modulated hood exhaust) Receiving doors blocked open “House” ventilation transferred to kitchen as additional make-up air

DVC systems operate dynamically between their preset minimum fan speeds and maximum ventilation system design airflows.

Balance at full speed Verify airflows at minimum fan speeds Let the systems modulate and save energy

Our Top 5

1. Avoid degrading exhaust hood capture and containment at all costs! Verify capture and containment at minimum design speeds

2. Control exhaust and make-up air whenever possible

3. Pre-balance all retro-fit projects. Will typically uncover existing underlying problems

4. Integrate with building EMS systems so that the individual systems work together

5. Commission, commission, commission!

Ultimately, a properly balanced ventilation system with proper capture and containment at the exhaust hood creates a happy customer

Proper Capture and Containment – Our Ultimate Goal

Schlieren Video

OK, Now The Real World

Exhaust Hood Capture Problem – Palo Alto Restaurant

OK, Now The Real World

Frayed Belt

Cat Litter

Pool of Oil

Fan NotAttachedTo Base

OK, Now The Real World

Noise and Velocity Issue at Zagat Rated Restaurant in San Francisco

Perfect World Application for DVC – matched systems

Demand Ventilation Controls Save Energy! Several Utilities offer direct incentives for these systems in both

“Deemed” and “Calculated” energy efficiency measures:

PG&ESMUD Southern California EdisonSoCal GasSDG&ESilicon Valley PowerCity of Palo Alto Utilities

www.culinairesystems.com

mike@culinairesystems.com

Mike: 916.596.0085 x801

Constant Volume Kitchen VentilationSystems Waste Energy!