1、33.1CHAPTER 33KITCHEN VENTILATIONCOMMERCIAL KITCHEN VENTILATION 33.1Commissioning. 33.1Ventilation Design 33.2System Integration and Design 33.2Energy Considerations. 33.4Commercial Exhaust Hoods. 33.7Cooking Effluent Generation and Control . 33.16Replacement (Makeup) Air Systems. 33.20HVAC System D
2、esign . 33.26Exhaust Systems . 33.27Exhaust Fans 33.28Fire Safety 33.29System Commissioning and Air Balancing 33.32Operations and Maintenance. 33.34RESIDENTIAL KITCHEN VENTILATION 33.35Exhaust Systems . 33.35RESEARCH 33.37HIS chapter focuses primarily on commercial kitchen ventila-Ttion (CKV) system
3、s in restaurants and institutional food servicefacilities, and incorporates the research and experience (including allsteps of the design process) amassed by TC 5.10 over the past twodecades. Although a brief section on residential kitchen ventilationhas been retained, only minor updates have been i
4、ncorporated overthe history of this chapter. Given ongoing debate on residentialrange hood performance, TC 5.10 anticipates sponsoring research toprovide a basis for enhanced design of residential kitchen ventilation(RKV) systems.1. COMMERCIAL KITCHEN VENTILATIONKitchen ventilation is a complex web
5、of interconnected HVAC sys-tems. The main components typically include (1) cooling to addressheat from cooking appliances, (2) replacement air to provide properpressurization during cooking operations, and (3) exhaust to removeheat and effluent generated by cooking appliances. System designincludes
6、aspects of air conditioning, fire safety, ventilation, buildingpressurization, refrigeration, air distribution, and food serviceequipment. Kitchens are in many buildings, including restaurantsand retail malls (see Chapter 2), hotels (Chapter 6), hospitals(Chapter 8), single- and multifamily dwelling
7、s (Chapter 1), educa-tional facilities (Chapter 7), and correctional facilities. Each buildingtype has special requirements for its kitchens, but many basic needsare common to all. This chapter provides an understanding of thedifferent components of kitchen ventilation systems and where theycan be a
8、pplied. Additionally, background information is included toprovide an understanding of the history and rationale behind thesedesign decisions.Kitchen ventilation has at least two purposes: (1) to provide acomfortable environment in the kitchen and (2) to ensure the safetyof personnel working in the
9、kitchen and of other building occupants.Comfort criteria often depend on the local climate, because somekitchens are not air conditioned. Kitchen ventilation ensures safetyby providing a means to remove the heat, smoke, and grease (cook-ing effluent) produced during normal cooking operations.HVAC sy
10、stem designers are most frequently involved in commer-cial kitchen applications, in which cooking effluent contains largeamounts of grease or water vapor. Residential kitchens typically usea totally different type of hood. The amount of grease produced inresidential applications is significantly les
11、s than in commercial appli-cations, so the health and fire hazard is much lower.The centerpiece of almost any kitchen ventilation system is anexhaust hood(s), used primarily to remove cooking effluent fromkitchens. Effluent includes gaseous, liquid, and solid contaminantsproduced by the cooking proc
12、ess, and may also include products offuel and even food combustion. These contaminants must beremoved for both comfort and safety; effluent can be potentially life-threatening and, under certain conditions, flammable. Finally, notethat the arrangement of food service equipment and its coordinationwi
13、th the hood(s) can greatly affect the energy used by these systems,which in turn affects kitchen operating costs. Quite often, the hoodselection and appliance layout is determined by a kitchen facilitydesigner. To minimize energy use and ensure a properly designedkitchen ventilation system, the HVAC
14、 engineer should reach out tothe kitchen designer and share the practices and ideas presented inthis chapter.SustainabilityKitchens are some of the most intensive users of energy for a givenfloor area when compared to other commercial or institutional occu-pancies. In addition to energy used during
15、cooking, the kitchen ven-tilation system must address the large amount of heat emitted orconvected into the kitchen from the cooking equipment, and supplyand condition the replacement air needed to support the cookingeffluent exhaust system as well as ensure acceptable indoor environ-mental quality
16、(IEQ). An additional factor to be considered is thecooking effluent, and any treatments that may be required before itis discharged into the atmosphere.Given these factors, it is imperative that the kitchen ventilationsystem be designed with careful consideration of both first costs andoperating cos
17、ts. Maintenance costs should also be considered,including scheduled equipment replacement (such as air filters), anycorresponding labor, and any production down time as a result of themaintenance.To ensure all of these criteria are accounted for in the kitchen ven-tilation design, the integrated bui
18、lding design approach described inChapter 58 is recommended.1.1 COMMISSIONINGBecause CKV systems are very complex operational environ-ments, it is strongly recommended that ASHRAE Standard 202 andthe recommendations in Chapter 43 for commissioning be followedfor any commercial kitchen ventilation pr
19、oject. Sections of thischapter contain the technical information necessary to address allfour phases of commissioning. Addressing the following topics isrecommended when developing and executing any commissioningplan:1. Owners project requirements (OPR)a. System manual outlinei. System selection: sp
20、ecific kitchen ventilation use re-quirements (by owner or design team)The preparation of this chapter is assigned to TC 5.10, Kitchen Ventilation.33.2 2015 ASHRAE HandbookHVAC Applications (SI)ii. Type of facility (e.g., commissary, quick service, full service, institutional)iii. Cooking appliances
21、selection based on menu, type of cooking, and special/unusual considerations iv. Other considerations1. System cost2. Kitchen space comfort targets3. Energy use and sustainability targets4. Replacement air requirements5. Cooking exhausta. Duct routing and egressb. Effluent control requirementsc. Air
22、 discharge and outlet restrictions6. Other mechanical servicesa. HVAC equipment locationb. Utility services7. Future expansion8. Ongoing maintenance requirements2. Design phasea. Systems manual outline (i.e., design intent): the engineers response to the OPRb. Hood selection based on appliance line
23、up (very critical because it affects exhaust rate)c. Replacement air method, and kitchen air movementd. Accounting for kitchen equipment heat gainse. System control strategies, including demand-controlled kitchen ventilation (DCKV) systemsf. Exhaust effluent control measuresg. Energy saving measures
24、h. Exhaust system requirementsi. Fire safetyj. Codes and standardsi. NFPA Standard 96ii. ASHRAE Standard 154iii. IMC (ICC 2012)iv. UL Standard 710v. UL Standard 7623. Construction phasea. Submittal review and coordination with all disciplinesb. Installation and execution with end use in mindc. Exhau
25、st duct constructiond. Air outlet and inlet locations and adjustmentse. Technical commissioning of the following:i. System controls for replacement air and exhaust air, including DCKV systems ii. Cooking effluent control equipmentiii. Cooking fire suppression systemsiv. Air system testing, balancing
26、, and adjustment4. Occupancy and operationsa. Owner and user training of systemsi. Exhaust and replacement air controls, including DCKV systemsii. Cooking effluent controliii. Cooking fire suppressionb. Maintenance schedulec. Recommissioning pland. Consequences of any revision/remodel (e.g., changin
27、g cooking equipment)1.2 VENTILATION DESIGNDesigning a CKV or even a high-end residential kitchen ventila-tion system requires a different design approach and process thanfor most traditional HVAC systems. Design considerations includelarge replacement air requirements, large internal heat gains,kitc
28、hen worker comfort, minimizing HVAC system energy use, andfire safety, all of which are equally high priorities that must beaddressed during system design.Necessary steps to design the ventilation systems for a commer-cial kitchen are as follows. Details for each step can be found in thesubsequent s
29、ections in this chapter, or in the other Handbook chap-ters.1. Kitchen facilities design (including cooking menu and appli-ance selection and placement). This design is typically per-formed by the food service consultant (FSC). Additionally,determine which appliances require an exhaust hood. 2. Exha
30、ust hood selection, including exhaust air rates. Often over-looked, but one of the most critical design decisions for any CKVsystem: hood selection directly affects exhaust rates, the corre-sponding replacement air requirements, CKV system heat gainand loss calculations, and the systems overall ener
31、gy use. Con-siderations includea. Appliance thermal plumeb. Type I or Type II, based on appliance use or process c. Hood style (e.g., canopy, island, backshelf)d. Energy saving options (e.g., side panels, extra overhang, demand control kitchen ventilation)e. Life-cycle cost analysis3. CKV system int
32、egration and design. Determine exactly whatthe CKV system should accomplish, and how to holistically inte-grate it into the building.4. Replacement air design. Addresses the need for delivering thereplacement air into the kitchen. Considerations includea. Transfer air, comfort supply air, or direct
33、makeup air (or any combination)b. ASHRAE Standard 62.1 compliancec. Adjacent zone air classificationsd. Replacement and supply air delivery systems5. CKV system controls. Maintain pressurization and comfort forthe kitchen, dining area, and if applicable any adjoining zones.Accommodate any demand con
34、trol systems, including DCKVand adjacent zones demand-controlled ventilation (DCV) sys-tem(s).6. Heat gain and loss calculations. Now is when these should beperformed.a. Appliance heat gainsb. Replacement air7. Exhaust system designa. Duct selection - typeb. Fire safetyc. Air discharged. Effluent co
35、ntrol devicese. Fire suppression8. HVAC system designa. Equipment selection b. Diffuser and return grille layout very critical9. Hood and replacement air commissioning specifications(e.g., air balancing, troubleshooting)Note: the CKV design engineer is recommended to engage theFSC during steps 1 and
36、 2 to identify areas where both designs can beharmonized for optimal CKV performance.1.3 SYSTEM INTEGRATION AND DESIGNIdeally, system integration and balancing bring the many venti-lation components together to provide the most comfortable, effi-cient, and economical performance of each component an
37、d of theentire system. In commercial kitchen ventilation, the replacementair system(s) must integrate and balance with the exhaust systemand/or facility HVAC system(s). Even optimal system designsKitchen Ventilation 33.3require field testing and balancing once installed. It is important toverify com
38、pliance with design, and equally important to confirmthat the design meets the needs of the operating facility. Air balanceis a critical step in any CKV commissioning process.The following fundamentals should be considered and applied toall food service facilities, including restaurants, within the
39、con-straints of the particular facility and its location, equipment, andsystems.PrinciplesAlthough there are exceptions, the following are the fundamentalprinciples of integrating and balancing food service facility systemsfor comfort, control, and economical operation:The building should always be
40、slightly positively pressurized(e.g. +1.25 Pa) compared to atmosphere to prevent infiltration ofoutdoor air. Infiltrated air contains contaminants and insects, andadds to the heat load.Every kitchen should always be slightly negatively pressurized(0.25 Pa) to adjacent rooms or areas immediately surr
41、ounding itto help contain odors in the kitchen and to prevent odor migrationout of the kitchen.System HVAC design should prevent air supplied to the kitchenfrom being returned and supplied to non-kitchen areas. Odor con-tamination is an obvious potential problem. In addition, in condi-tions such as
42、seasonal transitions, when adjacent zones may be indifferent modes (e.g., economizer versus air conditioning or heat-ing), comfort may be adversely affected. Ideally, the kitchenHVAC system should be separate from all other zones HVACsystems. Three situations to consider are the following:During sea
43、sonal transitions, the kitchen zone may require airconditioning or may be served by ventilation air only, while din-ing areas require heating. Even in kitchens that require coolingwhen the adjacent dining areas require heating, it is still impor-tant to maintain the pressure differential between the
44、se spacesand continue transfer of dining-area air into the kitchen.To limit kitchen personnel discomfort, it is important to controlthe low-temperature MUA set point and prevent drastic temper-ature variations between the kitchen space and MUA beingintroduced. If dedicated kitchen MUA requires heati
45、ng, ther-mostatic control of the MUA heating source should ideally bebased on kitchen space temperature rather than outdoor air tem-perature. MUA heating should be interlocked with kitchenHVAC cooling to prevent simultaneous heating and cooling.HVAC thermostat locations in kitchens must consider the
46、potential conflicting temperatures.Ideally, there should be no perceptible drafts in dining areas, andtemperature variations of no more than 0.6 K. Kitchens might notbe draft-free; however, velocities at or near exhaust hoods shouldbe no greater than 0.4 m/s. Kitchen comfort is greatly impactedby ra
47、diant heat in work areas, but it is desirable to maintain sen-sible temperatures within 3 K of design conditions. These con-ditions can be achieved with even distribution and thoroughcirculation of air in each zone by an adequate number of regis-ters sized to preclude high air velocities. If there a
48、re noticeabledrafts or temperature differences, dining customers will beuncomfortable and facility personnel are generally less comfort-able and less productive.Both design concepts and operating principles for proper integra-tion and balance are involved in achieving desired results undervarying co
49、nditions. The same principles are important in almostevery aspect of food service ventilation.In restaurants with multiple exhaust hoods, or hoods with de-mand control systems, exhaust airflow volume may vary throughoutthe day. Replacement air must be controlled to maintain properbuilding and kitchen differential pressures to ensure the kitchenremains negative to adjacent areas at all operating points. The morevariable the exhaust, or the more numerous and smaller the zonesinvolved, the more complex the design, but the overall pressurerelationship principles must be maintained to
