SECTION K - HOT WATER SUPPLY REQUIREMENTS

Transcription

1 SECTION K - HOT WATER SUPPLY REQUIREMENTS REFERENCES (Chapter ).06 Sanitary Facilities and Controls. Amended. (1) Water (h) Capacity 2.06 Sanitary Facilities and Controls. Amended. (2) Plumbing (c) Hand Sink Installation..05 Equipment and Utensils. Amended. (6)Maintenance and Operation (j) Mechanical Warewashing 1& 2.05 Equipment and Utensils. Amended. (2)Design and Construction (bb) 1.05 Equipment and Utensils. Amended. (6) Maintenance and Operation (l) Mechanical Warewashing 1.05 Equipment and Utensils. Amended. (6) Maintenance and Operation (n) Manual & Mechanical Warewashing. I. Background: 1. Purpose: A. A critical factor in preventing foodborne illnesses in a food facility is the provision of an adequate supply of hot water for the washing of hands, utensils, equipment, and the facility itself. The installation of a properly sized water heater will ensure that a sufficient amount of hot water will be available at all times. B. The purpose of these guidelines is to provide a set of criteria that will assist architects, designers, contractors, establishment owners and food service permit applicants in the proper sizing of water heaters to adequately meet the anticipated hot water demands of food facilities in Georgia. Similarly, these guidelines are provided to aid the Health Authority or the County Environmental Health Specialist (EHS) during the plan review process to obtain reasonable assurance of the adequacy of the food establishment s water heating equipment capacity to meet the demand of the establishment. Food facilities with water heaters sized according to these criteria should be capable of complying with the requirements for providing an adequate hot water supply as required by the Georgia Food Service Rules and Regulations Chapter subsection (1) (h) General Requirements: A. All newly constructed or existing buildings being converted into a food service establishment shall be provided with a hot water supply dedicated to the food service operation sufficient to satisfy the continuous and peak hot water demands of the food establishment at all times the establishment is in operation. Hot water for hand washing shall be tempered water at a temperature between 100 F and 110 F (43 C) through a mixing valve or combination faucet. Depending upon the design of the machine, the temperature of wash solution in spray-type warewashers that use hot water to sanitize must be 150 F (66 c) to 165 F (74 c) for washing and Page K1 of K19

2 165 F (74 c) to 180 F (82 c), not to exceed 194 F (90 c), for sanitizing. The maximum sanitizing temperatures of 165 F (74 c) to 180 F (82 c), not to exceed 194 F (90 c) do not apply to high pressure and temperature systems with wandtype, hand-held, spraying devices used for in-place cleaning and sanitizing of equipment such as meat saws. The temperature of the wash solution in spray-type warewashers that use chemicals to sanitize shall not be less than 120 F (49 c). The water temperature for manual hot water sanitization must be at least 171 F (77 c). For the purposes of sizing hot water generating capability of the food service establishment, a supply temperature requirement of 140 F must be provided at each fixture and to the mechanical dishwashing machines. This is needed to enable warewashing machine booster heaters to operate satisfactory and to ensure adequate hot water for cleaning and sanitizing operations. Further, water heaters and their installation must be in compliance with all Federal, State and local building and plumbing code requirements and water heaters that use reclaimed heat from equipment to heat water must be evaluated on a case-by-case basis. II. Storage Tank Type Water Heaters: 1. Sizing Requirements for Storage Tank Water Heaters: A. For food facilities that utilize multi-service eating and drinking utensils, the water heater shall have the ability to provide hot water at a rate equal to or greater than 100% of the computed peak hourly hot water demand of the establishment, in gallons per hour (GPH). B. For food facilities that use only single-service eating and drinking utensils, or do not use utensils at all, the water heater shall have the ability to provide hot water at a rate equal to or greater than 80% of the computed hourly peak hot water demand of the establishment, in GPH. C. The hourly hot water demand for the food facility, in GPH, is based upon a twentyfour hour basis and it is calculated by adding together the estimated hot water demands for all sinks and other equipment, such as dishmachines, which utilize hot water. In the absence of specific hot water usage figures for equipment, as given within manufacturer s equipment specification sheets, Table K-1 and notes to Table K-1 shall be used to calculate peak hot water demand See Appendix J within PART- II of this Manual for Peal Hourly Hot Water Demand Calculation Worksheet. The hot water demands for automatic warewashers, such as dishmachines, glasswashers, and potwashers are found in NSF International listings or listings established by other nationally recognized testing laboratories. Page K2 of K19

3 TABLE K-1 PEAK HOURLY ESTABLISHMENT HOT WATER DEMAND Equipment Type Gallons Per Hour Quantity Gallons/hour/day Totals Vegetable sink X 15 = Single food prep sink X 20 = Double food prep sink X 40 = 3 - Compartment Pot sink X 60 = 4-Compartment Pot Sink X 80 = Pre-rinse for dishes-shower head type X 45 = Bar sink three-compartment X 25 = Chemical sanitizing glasswasher X 60 = Lavatory X 5 = Cook sink X 10 = Hot water filling faucet X 15 = Bain Marie X 10 = Coffee urn X 5 = Kettle stand X 5 = Garbage can washer X 50 = Janitor s sink X 15 = Utility or Curbed cleaning facility X 20 = Nine and twelve pound clothes washer X 45 = Sixteen pound clothes washer X 60 = **(Clothes washers See Note #2) Employee shower X 20 = **Warewashing machine (See note #1) X = **Hose Reels (See note #3) X = Other Equipment (See note #4) X = Peak Hourly Hot Water Demand = ( ) Page K3 of K19

4 Notes to Table K-1 Note #1: Hot water demand for warewashing machines shall be 100% as per ANSI/NSFI listings. Note #2: Clothes Washer Calculation: A. Limited Use/Clothes washer used one to two times per day; beginning or ending of day operation GPH = [60 (for16lb.) & 45 (for 9lb. to 12 lb.)] GPH x 25%. B. Intermediate Use/Clothes washer used three to four times per day; GPH = [60 (for16lb.) & 45 (for 9lb. to 12 lb.)] GPH x 45%. C. Heavy Use/Clothes washer used once every two hours; GPH = [60 (for16lb.) & 45 (for 9lb. to 12 lb.)] GPH x 80%. D. Continuous Use/Clothes washer used every hour; GPH = [60 (for16lb.) & 45 (for 9lb. to 12 lb.)] GPH x 100%. Note #3: Hose 20 GPH for first reel & 10 GPH for each additional reel. Note #4: Other equipment not listed in Table E-1 shall be as per the manufacturer s equipment specification sheets. D. The following examples are provided to explain how to calculate the total hourly hot water demand: (1). Food facility that utilizes only single service eating and drinking utensils: Assume: 1 X Three compartment 60 GPH = 60 GPH 2 X Hand 5 GPH each = 10 GPH (5 GPH each) 1 X Janitorial 15 GPH = 15 GPH Total hourly hot water demand = (85 GPH) (85 GPH) X 80% allowance for single-service utensils = (68 GPH) For the food facility in this example, a water heater would be required, which will have enough British Thermal Units (BTU) (if gas operated) or Kilowatts (KW) (if electrically operated) size rating to recover 68 Gallons per Hour (GPH). Page K4 of K19

5 (2). Food facility that utilizes multi-service eating and drinking utensils: Assume: 1 X Three-compartment 60 GPH = 60 GPH 1 X Warewashing dish 80 GPH = 80 GPH 1 X Hand spray 45 GPH = 45 GPH 1 X One-Compartment food prep sink (20 GPH) = 20 GPH 2 X Hand 5 GPH each = 10 GPH 1 X Janitorial 15 GPH = 15 GPH Total hourly hot water demand = (230 GPH) Since the food facility in this example uses multiservice eating and drinking utensils, 100% of the computed hourly hot water demand must be provided. Therefore, a water heater would be required that has the capability to recover 230 Gallons Per Day (GPH). E. The following are examples for determining the energy input (BTU for gas water heaters) and KW (kilowatts for electric water heaters): (1). Electric Water Heater Sizing: Given: The peak hot water demand for an establishment has been calculated to be 68 GPH. An electric water heater with a kilowatt (KW) input rating of 14 KW has been specified within the food service plans for review. We need to verify whether or not the proposed water heater is correctly sized. Formula: KW input = GPH X 100ºF Rise X 8.33 lb. per gallon of water Thermal Efficiency (See Note#1) X 3412 BTU s/ KW Note #1: The thermal efficiency for electric water heaters, unless otherwise listed by ANSI/NSFI will be assumed to be 98% or.98. Example: KW input = 68 X 100 X X 3412 = or (17 KW) In this example, you will need an electric water heater with a kilowatt rating of at least 17 KW. The foodservice plans for review did not specify such a water heater as calculated. Therefore, the heater would not be compatible with the demands of the establishment. A water heater with at least 3 KW (17 KW 14 KW = 3 KW) additional KW capacity will be needed to meet the establishment hot water peak demand. Page K5 of K19

6 (2). Gas Water Heater Sizing: Given: The peak hourly hot water demand for an establishment has been calculated to be 230 GPH. A gas water heater with a BTU input of rating of 218,802 BTU s has been specified within the food service plans for review. We need to verify whether or not the proposed water heater is correctly sized. Formula: BTU input = GPH X 100ºF Rise X 8.33 lb. per gallon of water Thermal Efficiency (See Note#2) Note #2: The thermal efficiency for gas water heaters, unless otherwise listed by ANSI/NSFI will be assumed to be 75% or.75. Example: BTU input = 230 X 100 X 8.33 = 255, or (255,453 BTU input).75 In this example, you will need a gas water heater with a BTU input energy rating of 255,453 BTUs. The foodservice plans for review did not specify the water heater as calculated; therefore, you cannot assume the heater would be compatible with the demand of the establishment. A water heater with at least 36,651 (255,453 BTU 218,802 BTU = 36,651 BTU) additional BTU capacity will be needed to meet the establishment s hot water peak demand. III. Requirements for Booster Heaters: 1. General Requirements: A. When a hot water sanitizing warewashing machine is used, a booster heater must be provided that will raise the incoming general-purpose hot water at a temperature of 140 Fahrenheit up to at least 180 Fahrenheit for the final sanitizing rinse cycle. Booster heaters shall be sized at a 40 Fahrenheit rise. Booster heaters may be incorporated within the design of the warewasher or be added as a separate unit at the warewashing machine. B. When sizing a booster heater, the hot water demand for the warewashing final sanitizing rinse cycle should be obtained from the NSF International listings or listings established by other nationally recognized testing laboratories. C. Use the following formulas when sizing warewashing machine booster heaters: (1). Electric Booster Heater Sizing: Page K6 of K19

7 Given: A hot water sanitizer warewashing machine with a final rinse hot water demand of 100 gallons per hour (GPH) is specified in plans for review. An electric booster heater with a kilowatt (KW) input rating of 10 KW has been specified within the food service plans for review. We need to verify whether or not the proposed booster heater is correctly sized. Formula: KW input = GPH X 40ºF Rise X 8.33 lb. per gallon of water Thermal Efficiency (Note#3) X 3412 BTU s/ KW Note#3 The thermal efficiency for electric booster heaters, unless otherwise listed by ANSI/NSFI will be assumed to be 98% or.98. Example: KW input = 100 X 40 X X 3412 = or 10 KW In this example you would need an electric booster heater with a kilowatt rating of 10 KW. The foodservice plans for review specified such a booster heater for the warewasher specified as calculated. You can now assume the booster heater would be compatible with the demand of the warewasher. 2. Gas Water Heater Sizing: Given: A hot water sanitizer warewashing machine with a final rinse hot water demand of 100 gallons per hour (GPH) is specified in plans for review. A gas booster heater with a BTU input rating of 10 KW has been specified within the food service plans for review. We need to verify whether or not the proposed booster heater is correctly sized. Formula: BTU input = GPH X 40ºF Rise X 8.33 lb. per gallon of water Thermal Efficiency (See Note#4) Note #4 The thermal efficiency for gas booster heaters, unless otherwise listed by ANSI/NSFI will be assumed to be 75% or.75. Example: BTU input = 100 X 40 X = 44, or 44,427 BTU input Page K7 of K19

8 In this example, you would need a gas booster heater with a BTU input energy rating of at least 44,427 BTU s. The foodservice plans for review specified such a booster heater for the warewasher specified as calculated. You can now assume the booster heater would be compatible with the demand of the warewasher. D. When a booster heater is installed below a drainboard, it shall be installed at least six inches above the floor and away from the wall, and in a manner that will allow accessibility for proper cleaning and servicing. IV. Installation Requirements: 1. Recirculation Pump: A. Where fixtures are located more than sixty feet from the water heater, it may become necessary to install a recirculation pump, in order to ensure that water reaches the fixture at required temperatures. Should it be shown by food service establishment planner to the satisfaction of the health authority that piping from water heaters can be effectively insulated to prevent significant heat loss before reaching fixtures, the requirement of a recirculation pump will not be necessary. 2. Water heaters shall be mounted in one of the following manners: A. On six-inch high, easily cleanable legs. B. On a four inch high coved curb base. All openings between the water heater and the base must be sealed in a watertight manner. C. On a properly finished and installed wall pedestal, positioned so that it is out of the work and traffic space. D. In an easily accessible location above a suspended ceiling. A permanently installed ladder will be required to access water heaters located above suspended ceilings; the ladder shall not be installed above food or utensil handling areas. Note: The Health Authority may allow alternate installation methods when a water heater is installed in an area separated from food and utensil handling areas, such as in a mechanical room. Local Building Codes should be consulted. 3. Common Mistakes Residential Water Heaters: Page K8 of K19

9 A. A common mistake with electric water heaters is the ordering and installing of a water heater with an upper element of 4500 watts, a bottom element of 4500 watts, and a total connected (or maximum) wattage of 4500 watts. On such a water heater only one element is operating at any one time. Many individuals do not observe the total connected wattage and assume that because each of the elements is 4500 watts their water heater has an input rating of 9000 watts. Water heater manufacturers have specific procedures for rewiring an electric water heater so that the upper and lower elements are operating simultaneously. Some manufacturers only permit rewiring in the factory. Field modifications will normally void warranties and any listings that the unit comes with. Prior to acceptance of a field modified water heater, the local health agency should ensure that the modifications were performed according to the manufacturer's recommendations and with the approval of the local building officials. The data plate on a field modified water heater must be changed to reflect the total connected wattage rating with both elements operating simultaneously. V. Instantaneous-Tankless-Water-Heaters: 1. Background: A. It is common for food service establishments to use appliances and equipment that utilize natural gas as a source of energy to operate. Equipment such as grills, deep fryers and water heaters commonly use gas to cook foods and to heat water. Over the recent years, the cost of natural gas and other energy resources coupled with rising food production cost has brought to bare an increase in the operational cost of most food service establishments. As a result, these establishments, existing and proposed, are searching to find ways to lower these costs so they can better compete in today s market. One of the ways food service establishments can cut operational cost is to utilize equipment and appliances that are energy efficient. B. Just like in the home, the cost of heating water is only second to that of operating air-conditioning. This pressure to reduce the cost of heating water within the home has created a need for innovation and as a result, industry has responded by developing a different kind of water heating appliance - one that only operates as result of demand, meaning it only heats water when it is requested to do so by the homeowner. And how does this new kind of water heating appliance reduce cost of heating water? The conventional water heater stores water in a tank and continuously consumes energy to maintain a set water temperature until the heated water is needed. The arrival of the instantaneous-tankless-water-heater only uses enough energy to heat water as it is needed; thereby, it utilizes far less energy than the traditional standard storage tank style water heater, providing the homeowner with substantial energy cost savings over time. It is this substantial energy cost savings that makes instantaneous-tankless-water-heaters attractive to current and prospective food service establishment operators and the industry has responded by manufacturing models for use in their establishments. Page K9 of K19

10 C. One of the advantages of an instantaneous-tankless-water-heater is its ability to provide a continuous supply of hot water. However, since the water passes through a heat exchanger, the water must flow through the unit slowly to assure proper heat transfer. Therefore, the quantity or rate at which the hot water is delivered can be significantly less than that provided by a storage-tank-style-water-heater. When hot water is utilized at several locations of the food facility at the same time, the flow of hot water to each fixture can be severely restricted. As a result and depending on the numbers and types of sinks and equipment utilizing hot water being present, more than one of these types of water heaters may be required to keep up with establishment demand for hot water. D. Instantaneous-tankless-water-heaters are designed to operate by injecting enough BTUs (British Thermal Units) into water as it flows by a heating coil or exchanger at a given rate. As such, their ability to meet demands placed on them for hot water depends on the design flow rates of equipment and fixtures utilizing hot water to operate properly. Therefore, it is imperative that instantaneous-tankless-waterheaters be sized to meet the peak hot water flow rate and volume demand of the hot water side of the potable water plumbing system of the proposed establishment. Once these systems have been designed to meet this stated peak demand in hot water, any future changes in equipment and fixtures, such as the act of removing aerators from faucets or the installation of a piece of equipment with a higher GPM rating by the establishment operator, will cause such systems to be undersized and a resulting inadequate hot water supply for the establishment. This occurrence of the lack of adequate hot water generation ability within the establishment will cause cleaning and sanitization problems for the establishment. To correct any under sizing effects due to an increase within the peak demand flow and volume rate of the hot water side of the establishment s potable water plumbing system, it may become necessary to increase the water heating system s design flow and volume rate to meet this new demand. The food service inspector must realize that it is the manufacturer of the food service equipment, such as warewasher and or fixtures that are installed on sinks, who determine the flow and volume rates for their equipment and fixtures. These manufacturer flow and volume rates are dependent upon the equipment and or fixture design and configuration as shipped from the manufacture and any changes made in the field could have an adverse effect on how the water heating system functions. Once an instantaneous-tankless-water-heater system has been properly designed by its manufacturer and or distributor and has been shown by the establishment s professional plans and specification preparer to meet the peak demand of the hot water side of the potable water system of the proposed food service establishment, close observation of changes made to fixtures and equipment is noted during inspections where such instantaneous-tanklesswater-heaters are installed. Page K10 of K19

11 2. General Sizing and Installation Requirements: A. If utilized instead of the traditional storage tank type water heaters and/or whether configured in single or combined units, instantaneous-tankless-water-heaters and associated distribution systems shall be sized appropriately. They shall be sized so as to be capable of generating a supply of hot water at a temperature of at least 140 Fahrenheit to all sinks, janitorial facilities, and other equipment and fixtures that use hot water, at all times. This hot water supply being generated must meet or exceed the peak hot water flow and volume rate demand, expressed as GPM (Gallons per Minute), throughout the food service establishment. Hot water at a temperature between 100 and 110 Fahrenheit shall be provided to each hand-washing lavatory through a mixing valve or combination faucet. Peak hot water flow and volume rate demand of the hot water side of the potable water plumbing system is defined as being equal to the combined total of the manufacturer s design flow and volume rate specification(s) for each piece of equipment and fixture at the potable water plumbing system s designed operating pressure in psi (pounds per square inch) utilizing hot water within the proposed establishment. B. When sizing instantaneous, tankless style water heater systems, special consideration must be given to certain fixtures, such as, pre-rinse nozzles at three compartment sinks and warewashers, mop sinks or hosebibbs, used for cleaning operations whereby hot water is used in flushing or rinsing operations. For such described fixtures, a minimum of 1 GPM will be used for each such fixture when calculating the peak demand flow and volume rate of the hot water side of the establishment s potable water plumbing system. Should more specific gallon per minute (GPM) flow and volume rate be listed within the manufacturer s specification documentation for fixtures and equipment that is greater than the minimum 1 GPM, then the greater figure will be used in sizing the water heating system. (Note: Hand lavatories and hand sinks must receive at least ½ GPM flow rate.) The following example is provided to explain how this sizing criterion is applied: (Example #1) Assume: 1 Three compartment Sink 2.0 GPM 2 Hand 0.5 GPM 1.0 GPM 1 Janitorial Sink 1.0 GPM 1 Vegetable Sink 2.0 GPM Total Peak Demand (6. 0 GPM) Page K11 of K19

12 In the Example #1, it is possible that one instantaneous-tankless-water-heater could be provided in order to supply a total peak flow and volume demand of not less than 6.0 GPM with a N-132 Model Unit. (Example #2) Assume: 1 Three compartment sink 2.0 GPM 5 Hand ½ GPM 2.5 GPM 1 Janitorial sink 1.0 GPM 1 vegetable sink 2.0 GPM 1 Warewasher (rated at 3.6 GPM) 3.6 GPM Total Peak Demand (11.1 GPM) In the Example #2, a bank of units consisting of two or more instantaneous-tanklesswater-heaters would have to be provided in order to supply a total peak flow and volume demand of not less than 11.1 GPM. C. To insure whether or not instantaneous-tankless-water-heater systems will meet hot water peak flow and volume demand throughout the food service establishment, food service plans for review must be provided with the water system manufacturer's specification sheets. These sheets must indicate the graphical performance curve(s) based on specific models, the degree rise (defined as 140 Fahrenheit water at equipment and fixtures) minus the degree Fahrenheit temperature of incoming water to the establishment at the coldest season of any year, as reported by the local water authority and gallons per minute flow rates. See Figure K-1 for an example of an instantaneous-tankless-water-heater performance flow chart. Further and in conjunction with the required graphical representation of model performance, a spreadsheet indicating numerical values for flow rates per model must be included within the instantaneous water heater specification documentation. (See Figure K-2 for an example). Page K12 of K19

13 FIGURE K Flow Chart FIGURE K-2 N-132M N-084 N-069M N-063S Flow Rate (GPM) gpm FIGURE K Temperature Rise (F) Page K13 of K19

14 FIGURE K-2 Temp Rinse N-132M N-084 N-069M N-063S Page K14 of K19

15 D. It should be noted that by examining the typical performance graph in Figure K-1 and the chart in Figure K-2, that each unit model of instantaneous-tankless-waterheaters tend to drop-off in hot water production (gallons per minute flow and volume rate) at various rates with each increase in degree rise variation. This dropoff in hot water production with each increase in degree rise variation per unit model is why you must know what the lowest temperature of incoming water to the unit or bank of units is at the coldest time of the year. Without this degree rise temperature determination, the water heating system cannot be correctly sized. It is strongly recommended that planers of these stated water-heating systems consult with the local water distribution authority servicing the location of the proposed food service establishment to document the incoming water temperature entering the establishment. In areas of Georgia where there is no water distribution system authority to consult with and or where an approved well is utilized as the establishment s potable water supply, it may become necessary to rely on published ground water data or actually measure incoming water temperature at the establishment. In these stated cases where wells are utilized for water supply to the proposed establishment, an engineer, an architect, a master plumber or well driller contractor, all licensed by the State of Georgia, will need to verify and document the incoming water temperature to the establishment and this documentation must be included within the food service plans and specifications upon submittal to the health authority for review. E. Food facilities that install an automatic warewashing machine that utilizes a large quantity of hot water may be required to provide an instantaneous-tankless-waterheater exclusively for the warewashing machine or incorporate a hot water recirculation system from the water heating system to the warewasher. instantaneous-tankless-water-heaters shall not be substituted for ware washing machine booster heaters for hot water sanitizing. ANSI/NSFI (American National Standards Institute/National Sanitation Foundation International) listings are used to determine the minimum GPM hot water demand for automatic warewashing machines - see Figure K-3 or while on the Internet, click onto for an example of such listings. Should these stated listings not be available for a particular make and model of warewashing machine or other equipment utilizing hot water, it shall be the responsibility of the food service plans preparer to provide the manufacturer s specification sheets giving the equipment design GPM flow rate operating requirements for hot water. Page K15 of K19

16 FIGURE K-3 HOBART CORPORATION WORLD HEADQUARTERS 701 SOUTH RIDGE AVENUE TROY, OH </TD< tr> Facility: DANVILLE, KY STATIONARY RACK DISHWASHING MACHINES Final Rinse (20 psi) Operating Time Model Rack Size Flow Usage (seconds) Footnotes Number Width gpm gph Wash Rinse Dwell Single Tank Chemical Sanitizing Door AM-14 20x [4] [5] [6] [7] AM-14 20x [4] [5] [6] AM-14C 20x [4] [5] [6] AM-14C 20x [4] [5] [6] [7] AM-14F 20x [4] [5] [6] AM-14F 20x [4] [5] [6] [7] AM-14T 20x [4] [5] [6] AM-14T 20x [4] [5] [6] [7] AM-14TC 20x [4] [5] [6] [7] AM-14TC 20x [4] [5] [6] LT-1 20x [4] [6] [4] Optional tabling and shelving fully complying with NSF Standard 2 may be provided. [5] Unit specified must have letter "L" following serial number on machine data plate. [6] Final rinse must contain 50 ppm minimum available chlorine. [7] Models with a shorter wash cycle (reduced 12 seconds) require a minimum wash temperature of 130 F. Page K16 of K19

17 3. Recirculation Pumps: A. The term cold water sandwich effect is a term that is used to describe the introduction of cold water into the hot water supply line during frequent on/off operation of an instantaneous-tankless-water-heater. The cold-water sandwich effect, when present, appears as a momentary drop in hot water temperature as it is discharged from a hot water supply outlet (i.e. restaurant hand lavatories, mop sinks, warewashing machines, etc.). This phenomenon is present in the operation of all instantaneous-tankless-water-heaters and it is a direct result of their operating principles used to heat water. B. The development of instantaneous-tankless-water-heaters required a departure from the common tank type storage water heater. Tank type water heaters heat a stored volume of water slowly over a long period of time (approximately 1 hour) and then maintain this stored water at a high temperature until used. It is the elimination of stored water from hot water systems that has resulted in the cold-water sandwich effect. C. For a better understanding of why a cold-water sandwich effect exists with instantaneous-tankless-water-heaters, the operating principles and safety mechanisms involved in their operation must be understood. The basic operation of all instantaneous-tankless-water-heaters as follows: (1.) Water flow sensor senses water flow through the heater. (2.) Burner ignition is initiated resulting in the production of hot water. (3.) Water flow and temperature is monitored and used to adjust the flow of gas to the burner, so that the outlet set point temperature is maintained. (4.) When water flow ceases, the water heater shuts off. To maintain a safe ignition sequence, steps (A) and (B) typically take up to 10 seconds. During this ignition sequence, a small amount of cold-water flows through the water heater. When hot water usage is stopped briefly and then started up again, this ignition sequence is repeated, and the small amount of cold water that passes through the water heater forms a cold water sandwich. It is this sequence of operations with these water-heating systems that cause a brief cold-water discharge at sinks and equipment until the unit has caught-up with the hot water demand at the point of discharge(s) from within the hot water side of the potable water plumbing system. It should be noted that the cold-water sandwich effect cannot be removed completely from instantaneous, tankless style water heater systems. The safety standards developed to insure the safe operation of water heaters require a delay in the ignition sequence of all gas Page K17 of K19

18 water heaters. In addition, electric type, instantaneous-tankless-water-heater systems too can experience this cold-water sandwich effect due to the time it takes the heating elements to be energized and reach heating temperatures. (5.) It is for the cold water sandwich affect that where fixtures are located more than sixty feet from the water heater, a recirculation pump with reserve tank may be considered as part of the instantaneous-tankless-water-heater system installation, in order to ensure that water reaches the fixture at a temperature of at least 140 F. This requirement is applicable to all applications, unless the instantaneous-tankless-water-heating system designer can satisfactorily incorporate other means within the system design to insure a constant flow of hot water at each hot water discharge point within the hot water side of the potable water plumbing system at the plumbing system s design operating pressure. On a case- by-case basis, it may be more practical to install a separate, water heater for high hot water flow demand equipment. In other cases, it may be more practical to install a separate, smaller instantaneoustankless-water-heater at remote fixtures, such as for restroom hand sinks. 4. Installation Requirements: A. The installation of instantaneous-tankless-water-heaters must follow the following guidelines: (1). instantaneous-tankless-water-heater systems are site fixture and specific in their design; therefore, they must be designed based on equipment and fixtures specified to be installed within the proposed or for those already installed within existing food service establishment. (2). Where feasible, instantaneous-tankless-water-heaters should be located in an area of the food facility separated from all food and utensil handling areas in such a way it will not impede routine cleaning of the establishment or harbor vermin. They must be installed in a location that facilitates the ease of access to the unit or units for servicing and monitoring. (3). Instantaneous-tankless-water-heaters must be installed according to any applicable codes or laws (Federal, State, Local, etc.). (4). Instantaneous-tankless-water-heaters must be designed and built according to standards set by American National Standards Institute (ANSI) accredited certification programs and others as per applicable plumbing or building codes or laws (Federal, State, Local) this will be determined by the water heating installation passing applicable building and or plumbing inspections. Page K18 of K19

19 (5). Instantaneous-tankless-water-heaters are properly sized when the total GPM of a single unit or the combined GPM of several units (bank of units) is equal to or exceeds the peak hot water flow and volume, expressed as GPM (Gallons per Minute), demand throughout the food service establishment at the designed operating pressure of the establishment s potable water plumbing system. (6). A Flow Meter shall be permanently installed adjacent to or incorporated within the designed instantaneous-tankless-water-heater unit or units so as to provide a means to monitor the flow rate in gallons per minute (GPM) within the food service establishment s hot water side of the potable water plumbing system. The flow meter must give a numerical readout of the flow of water as it passes through the instantaneous-tankless-water-heater. The flow meter must be durable and capable of maintaining its accuracy and of withstanding the design operational temperatures and design pressures of the hot water side of the potable water plumbing system. The purpose of this flow meter is to ensure the continued compatibility of the water heating system with the hot water peak demand flow and volume rate of the establishment. (7). In the event of the replacement of a tank type water heater; or during the planning of a new proposed food service establishment with an instantaneoustankless-water-heater system; or where no data is available for existing fixtures and equipment that uses hot water, the health authority may request a report from an engineer, architect or master plumber who is licensed to do work in the State of Georgia. Within this report, the licensed professional will list each fixture and piece of equipment utilizing hot water by common name, make and model along with its corresponding flow rates in gallons per minute. In addition, said report will give the total combined gallons per minute flow rate of listed fixtures and equipment utilizing hot water at the establishment s potable water system s designed operating pressure expressed as pounds per square inch (PSI). The report will be generated on the design professional s letterhead and it will bare the designer s name, title, date of report and his State of Georgia professional license number. Page K19 of K19