Optimizing & Integrating the System of the. Advances in Commercial Kitchen Ventilation (CKV) using Green Tips & Tricks from FSTC Research!

Transcription

1 Advances in Commercial Kitchen Ventilation (CKV) Optimizing & Integrating the System of the Future using Green Tips & Tricks from FSTC Research! Don Fisher Manager, PG&E Food Service Technology Center Alcosta Blvd., Suite 101 San Ramon, CA

2 Efficiency Vermont is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non-aia members are available upon request. This program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

3 Learning Objectives By the end of this program, participants will be able to: Inform consultants, contractors and owners of the energy/cost saving opportunities by integrating ventilation strategy in their commercial kitchen. Inform attendees as to how to implement demand control ventilation for kitchens. Provide quantifiable savings ranges for demand control ventilation strategies. Describe available technologies for optimizing kitchen ventilation and controls.

4 Course Evaluations In order to maintain high-quality learning experiences, please access the evaluation for this course by logging into CES Discovery and clicking on the Course Evaluation link on the left side of the page.

5 More than 3 Billion CFM exhausted from Commercial Kitchens in the U.S.

6 dominated by single-speed systems!

7 Why do we care? $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $

8 Outdoor Air Load Calculator and Fan Energy Estimator Free Download:

9 Los Angeles San Francisco Chicago Fairbanks New York Phoenix Atlanta Miami Heating/Cooling Load (kbtu/yr) Climate Effect 450, , , , , , , ,000 50, cfm Outdoor Air 24 hour per day Heated to 65F Cooled to 76F 70% RH Cooling Heating

10 Annual MUA Heating (kbtu/yr) 250,000 Heating Load vs. MUA Temperature 1000 cfm, 24-hour operation, 365 days per year in Chicago 200, ,000 50% reduction 100,000 50, MUA Temperature (deg F)

11 Hotel in San Francisco 50,000 cfm exhaust from kitchens!

12 Makeup air temperature 70ºF Outdoor air temperature = 50ºF

13 Simultaneous cooling!

14 Turned down all the duct stats! $50,000 per year saving in gas alone!

15 Exhaust Air Heat Recovery in Kitchen Ventilation?

16 Air-to-Air Heat Recovery Unit

17 Air-to-Air HX Toronto Restaurant

18 Gas Cost $9,000 $8,000 $7,000 $6,000 $5,000 $4,000 $3,000 $2,000 $1,000 Baseline Actual $0 Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct 36% reduction = $22,600 per year! (at $1.30/therm)

19 Standard If a kitchen/dining facility has a total kitchen hood 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.

20 CKV: The Design Challenge! There is no piece of equipment in the commercial kitchen that generates more controversy that the exhaust hood!

21 The plan view

22 The elevation view 21-ft wall canopy hood Exhaust = 5000 cfm (240 cfm/ft) Un-tempered Makeup = 4500 cfm (90% of exhaust) Translates to one hot kitchen!

23

24 Average of Operative Temperature for Kitchen Type and Kitchen Zones with 95% confidence interval (100 kitchens) F Note: c is Cooking, p is Preparation, and d is Dishwashing zone.

25 Suggested Thermal Comfort Zone for Commercial Kitchens

26 Someday thermal comfort in kitchens will take the design stage.

27 Will integrated CKV-HVAC Design improve thermal comfort? And what does CKV-HVAC integration really mean? Conversely, what does NOT integrating CKV with HVAC mean?

28 Non-integrated design 8000 cfm 1000 cfm 7000 cfm

29 Integrated design 3000 cfm 6000 cfm 3000 cfm

30 On an air balance schedule the difference is very subtle 8000 cfm 1000 cfm 7000 cfm Non-integrated design

31 but the thermal comfort impact may be huge! 3000 cfm 6000 cfm 3000 cfm Integrated design

32 CKV/HVAC Design Strategies Design Guide 1: Minimize design exhaust rate Group appliances according to effluent production and associated ventilation requirements. Engineered UL listed canopy hoods to increase effectiveness and reduce heat gain. Use proximity hoods where applicable. Side panels and end walls! How low can you go? Download at:

33 depends on Appliance Category and Usage vs.

34 also on Hood Style & Design

35 Food Service Technology Center operates the Commercial Kitchen Ventilation Lab Lab Originally Designed by McDonald s for Optimizing Hood Performance Enhanced with Schlieren Flow Visualization!

36 Wall Canopy with Displacement MUA (C&C = 4100 cfm, 2 charbroilers cooking)

37 Proximity Hood with Displacement MUA (C&C = 1250 cfm, 2 charbroilers cooking)

38 Proximity (Backshelf) Hood

39 Good intentions!

40 Good design! McDonald s set an industry standard!

41 Lab-Based Hood Design

42 Redesigned for Clamshell Grill

43 Somebody tried to copy

44 LEED design for another QSR 30% Design Airflow Reduction with DCV (temp only)

45 Wall-Mounted Canopy

46 partial end panels do the job!

47 Exhaust Rate (cfm/ft) Multiple configurations of appliances under various 10-ft. wall canopy hoods (approx. 90 tests) with and without partial side panels No Panels Partial Panels 30% reduction in airflow!

48 Overhang vs. Rear Gap

49 Rear Seal Investigation Front Overhang to Appliance [inches] Front Overhang to Cooking Surface [inches] Distance Between the Rear of the Appliance and Backwall [inches]

50 C&C Exhaust Rate [cfm] Seal gap behind appliances! cfm/ft 400 cfm/ft 340 cfm/ft 280 cfm/ft inch Front overhang Overhang 126 inch Front overhang Overhang 1812 inch Front overhang Overhang Without Rear Seal Between Appliance & Wall With Rear Seal Between Appliance & Wall 0

51 Hoods are not created equal

52 Laboratory Comparison of Wall-Canopy Hood Performance using ASTM F Standard Test Method for Capture and Containment of Commercial Kitchen Exhaust Ventilation Systems

53 The setup

54 The Standard Challenge!

55 Heavy-duty appliance challenge

56 With and without partial side panels 50in. 4in. 50in. 50-in. x 50-in. Side Panel 45

57 C&C Exhaust Rate [cfm] Heavy-duty challenge results ASHRAE Standard % reduction CB/CB/CB CB/CB/CB CB/CB/CB Without Side Panels With Side Panels With Side Panels With Rear Seal Manufacturer 1 Manufacturer 2 Manufacturer 3 Manufacturer 4 Generic Hood-Max Overhang Generic Hood-Min Overhang

58 CKV/HVAC Design Strategies Design Guide 1: Reduce design exhaust rate Group appliances according to effluent production and associated ventilation requirements. Engineered UL listed canopy hoods to increase effectiveness and reduce heat gain. Use proximity hoods where applicable. Side panels and end walls! Design Guide 2: Optimize makeup air delivery to kitchen No short-circuit hoods! Introduce replacement air at low-velocity

59 4-Way Diffuser Set-up

60 8-Ft Wall Mounted Canopy Hood 1400 SCFM to 4 Way

61 and with low-velocity makeup air

62 No 4-Way Diffusers Near Hood!

63 Displacement Ventilation Displacement Units

64 Perforated Supply Plenum (PSP)

65

66 CKV/HVAC Design Strategies Design Guide 1: Reduce design exhaust rate Group appliances according to effluent production and associated ventilation requirements. Engineered UL listed canopy hoods to increase effectiveness and reduce heat gain. Use proximity hoods where applicable. Side panels and end walls! Design Guide 2: Optimize makeup air delivery to kitchen No short-circuit hoods! Introduce replacement air at low-velocity Design Guide 3: Integrate the CKV system with the HVAC system Maximize dining room outdoor air as replacement air for the hood/minimize local makeup air. Consider using HVAC system to replace 100% makeup air. Consider demand ventilation controls (DCV) to kitchen exhaust and integrate with MUA and/or HVAC outdoor air supply

67 The first question to be answered is: How much occupancy ventilation air (ASHRAE Standard 62) is available for use as transfer air? 1) 0.20 cfm x ft 2 or 2) 15 cfm/person x maximum occupancy Must select the greatest of the two. In restaurants, the second will almost always be larger.

68 Casual Dining Example: 5265 ft 2 with 150 seats Assume 10 serving staff Design occupancy = 160 people 0.2 cfm x 562 ft 2 = 585 cfm 15 cfm x 160 people = 2400 cfm

69 Base Case Cookline & Exhaust Hood 18 ft Design Exhaust = 7200 cfm (400 cfm/ft x 18 ft)

70 Base Case, Casual Dining Air Balance.

71 Case I: Cookline & Exhaust Hoods ft 5.5 ft Hood over griddle & fryers: ft. x 250 cfm/ft = 2,560 cfm Hood over broiler & range: 5.5 ft. x 400 cfm/ft = 2,200 cfm Total Exhaust Rate: 4760 cfm 4800 cfm

72 Case I, Optimized Design Air Balance with Engineered Hoods and MAU Size Reduced. Without consideration for HVAC outdoor air, the MUA unit could have been sized at 80% or approximately 4000 cfm

73 Case II: Cookline & Exhaust Hoods 5.5 ft 11 ft Custom backshelf hood over griddle & fryers: 11 ft. x 150 cfm/ft = 1,650 cfm Custom canopy hood with full side panels over broiler & range: 5.5 ft. x 300 cfm/ft = 1,650 cfm Total Exhaust Rate: 3,300 cfm

74 Case II, Optimized Design Air Balance with Transfer Air Maximized Note: MUA unit has been eliminated!!!

75 And the final touch: Demand-Controlled Ventilation (DCV)

76 Full Speed! 3000 cfm 6000 cfm 3000 cfm

77 Half Speed! 3000 cfm 3000 cfm

78 Winnipeg Hospital (My first DCV-CKV project) 30 years ago!

79 Design Approach: Reduced exhaust and makeup air Side panels and glass back wall for single island canopy Filter blanks in sections not over appliances Air-to-air heat recovery to preheat makeup Two-speed system (3000 ft/min duct velocity on high speed).

80 1500 ft/min minimum now 500 ft/min

81 Demand-Controlled Ventilation (DCV)

82 The Potential Estimated installed base of 10,000 DCV systems (based on author s intel) as this technology has slowly emerged over the last 25 years. There are approximately 1,000,000 Commercial Foodservice Establishments in the U.S. and Canada. Assuming just two exhaust hood systems per facility, there are probably 2,000,000 exhaust hoods in operation. This represents a market penetration of only 0.5%. The potential for DCV is huge!

83 Demand Controlled Ventilation (DVC) Strategies controlled on a time-of-day basis proportional to appliance energy use controlled by exhaust temperature controlled by sensing smoke or steam produced by cooking process controlled by measuring cooking surface temperature or activity controlled by direct feedback from cooking equipment (NAFEM Online Protocol) controlled by combinations of the above

84 Appliance Control No Load - Low Speed! 2-Speed Fan Interlocked with 2-Sided Griddle

85 Demand Ventilation Control Technologies Halton Duct Temperature Sensor & Infrared Sensors Melink Duct Temperature Sensor & Smoke Detection Temperature Sensors CaptiveAire Gaylord Greenheck Streivor Air Spring Air

86 Variable Frequency Drives (VFD) Essentially electronic motor starters that replace magnetic starters Add flexibility to direct drive fans Cornerstone of a DVC system May be considered a separate value proposition from DVC

87 FSTC s First Project the PTK

88 Average Energy Rate (kw) Old Exhaust System (w/o EMS) 3.5 Exhaust Fan 1 (4000 CFM) Exhaust Fan 2 (4500 CFM) Make-Up Air :00 AM 2:00 AM 4:00 AM 6:00 AM 8:00 AM 10:00 AM 12:00 PM 2:00 PM 4:00 PM 6:00 PM 8:00 PM 10:00 PM 12:00 AM Time of Day

89 Average Energy Rate (kw) Old Exhaust System (with EMS) 3.5 Exhaust Fan 1 (4000 CFM) Exhaust Fan 2 (4500 CFM) Make-Up Fan :00 AM 2:00 AM 4:00 AM 6:00 AM 8:00 AM 10:00 AM 12:00 PM 2:00 PM 4:00 PM 6:00 PM 8:00 PM 10:00 PM 12:00 AM Time of Day

90 New Exhaust System KEF-1 (4000 CFM) Orginal KEF-1 KEF-2 (4500 CFM) Orginal KEF $5000 fan energy saving! 3.0 Average Energy Rate (kw) Make-Up Air Orginal Make-Up Air :0 2 1 AM 00 2: AM 00 4: AM 00 6: AM 00 8: AM 0 :0 0 1 AM 0 :0 2 1 PM 00 2: PM Time of Date 00 4: PM 00 6: PM 00 8: PM 0 :0 0 1 PM 0 :0 2 1 AM

91 Daily Fan Energy (kwh/day) Total Daily Fan Energy $4875 $3250 $0.10/kWh Original System Original System with EMS Retrofit System with Controller

92 Our Second Case Study The Mark Hopkins Hotel in San Francisco

93 Hotel Kitchen 3:00 PM No appliance use but exhaust at 100% Front Line Back Line

94 12:00 AM 1:15 AM 2:30 AM 3:45 AM 5:00 AM 6:15 AM 7:30 AM 8:45 AM 10:00 AM 11:15 AM 12:30 PM 1:45 PM 3:00 PM 4:15 PM 5:30 PM 6:45 PM 8:00 PM 9:15 PM 10:30 PM 11:45 PM kw Fan Power with and w/o DCV With and Without Melink Exhaust and Makeup Fan Power With Melink DV 5.3 kw W/O Melink C DV 14 kw C Avg. Reduction = 8.7 kw $10,000 fan energy saving! 0 Time

95 Summary Without Melink Intelli-Hood Controls Design Exhaust Ventilation Rate Exhaust & Makeup Fan Power Exhaust & Makeup Fan Energy With Melink Intelli-Hood Controls Reduced (Average) Exhaust Rate Reduced (Average) Fan Power Reduced Fan Energy Energy Savings Effective Exhaust Reduction Makeup Air Heating Saving Average Demand Reduction Average Fan Energy Saving Cost Savings 19,500 cfm 14 kw 336 kwh/d 13,750 cfm 5.3 kw 127 kwh/d Fan Energy Savings* $9,910 Makeup Air Heating Savings* $9,460 Total Cost Savings with Melink Control $19,370 Installed Cost of Intelli-Hood Controls $15,000 Payback Case Study: Mark Hopkins Hotel * based on $0.80/therm and $0.13/kWh 5,750 cfm 11,826 therms 8.7 kw 209 kwh/d < 1 year

96 Third Case Study Wall-Mounted Canopy Hood and Typical Fan Power Profile for a Campus Dining Facility

97 All California DCV Case Studies to Date

98 Technical Feature: ASHRAE Journal February 2013

99 CAUTION: The CKV system must work effectively as single-speed system before DCV is applied.

100 The Hood Tune-Up

101 Hood 2

102 End Panels Pass the Test!

103 Temp-Based DCV (in Toronto): Reduced MUA Heater Run Time by 40% Calculated savings: - fan energy $ MUA heating $ Total $6580

104 Standard If a kitchen/dining facility has a total kitchen hood 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.

105 The Future With the specification of a DCV system, there is no need to take chances with a design exhaust ventilation rate that is too low. Effective commissioning of a DCV system can maximize its performance. The CKV system must work effectively as singlespeed system before DCV is applied. Until appliances communicate directly with the DCV system, the DCV technology application will not realize its full return on investment potential. And in the future, the DCV system should communicate/integrate with the EMS system.

106 CKV-HVAC Integration Recap: 1. Optimize hood design and reduce the design exhaust airflow rate. 2. Optimize makeup air delivery to kitchen minimize impact on hood performance. 3. Maximize transfer air/minimize local makeup air. 4. Strive for 100% replacement air through HVAC units (versus using a conventional MAU unit without cooling), or 5. Consider using a dedicated 100% replacement air unit (RAU). 6. Apply demand ventilation control of hoods where cost effective.

107 DCV, Heat Recovery & Strategic Introduction of MUA could potentially

108 Your online toolbox Reports Energy saving tips Design guides Cost calculators Energy Star Rebates

109 Questions?