CFLC ClearFire Condensing Boiler. Boiler Book 05/2018

Transcription

1 CFLC ClearFire Condensing Boiler Boiler Book 05/2018

2 Table of Contents FEATURES AND BENEFITS PRODUCT OFFERING DIMENSIONS AND RATINGS PERFORMANCE DATA List of Figures AluFer Inserts Burner service Premix Burner Technology Model CFLC Cutaway View CFLC Control Panel Model CFLC Dimensional Views CFLC Efficiency Curves Waterside Pressure Drop Condensate Piped Direct to Drain Condensate Treatment Tank - external Condensate Treatment Tank - internal Gas Piping Schematic Gas Header Piping Model CFLC Minimum Room Clearance Dimensions Vent Terminations Vertical Stack with Inside Combustion Air Vertical Stack with Direct Venting/Sealed Combustion Two Opening Outside Wall Method Two Opening Ducted Method One Opening Method Two Opening Engineered Method Optional Direct Vent/Sealed Combustion Kit Falcon pinout List of Tables U.S. Standard Dimensions Model CFLC Boiler Metric Dimensions Model CFLC Boiler Model CFLC Boiler Ratings (Sea Level to 2000 Feet) CFLC Efficiencies Model CFLC Boilers: Natural Gas, Estimated Emission Levels Noise Level (dba) measured 3 feet in front of boiler CFLC Flow Rates* CFLC Flow Rates* (Metric) Model CFLC Minimum Over Pressure Requirements (100% water) Model CFLC Water Chemistry Requirements Model CFLC Water Temperature Data (Non-Glycol) Glycol Application Guidelines - Model CFLC Model CFLC Maximum Condensation CFLC Max Condensation Model CFLC Minimum and Maximum Gas Pressure Model CFLC Minimum Required Gas Pressure Altitude Correction Altitude Correction for Input Capacity at Various Altitude Levels Room Air Requirements CFLC Combustion Air and Flue Venting Requirements Operating Conditions - Controller Operating Conditions - Display/Interface Operating Conditions - VFD Falcon control sequence (Central Heat)

3 MODEL CFLC Features and Benefits MODEL CFLC FEATURES AND BENEFITS Compact Firetube Design The Model CFLC boiler is a durable firetube condensing hot water boiler. The internal extended-heating surface tubes provide very high levels of performance in a compact space, offering over 6 square feet of heating surface per boiler horsepower, providing many years of trouble free performance. Advanced Technology Tubes are constructed from UNS S32101 duplex stainless steel with AluFer tube inserts (lower vessel) and carbon steel with rifled surface (upper vessel) for optimal heat transfer. Figure 1. AluFer Inserts Advanced Construction The extended heating surface design provides the ideal solution for the demands of a condensing boiler and helps to recover virtually all the latent heat of the flue gas. Each tube consists of an outer stainless steel tube (waterside) and the AluFer extended surface profile on the flue gas side. High Efficiency With the extended heating surface tubes the CFLC boiler will provide fuel to water efficiency of up to 99% at low fire and 95% at high fire. Ease of Maintenance The powder coated steel casing is designed for easy removal and re-assembly. As shown in Figure 2, the burner is hinged for simple opening for inspection of the burner cylinder, tubes and tube sheets. Figure 2. Burner service Quality Construction ISO 9001:2001 certified manufacturing process ensures the highest degree of manufacturing standards are always followed. ASME Code construction ensures high quality design, safety, third party inspection, and reliability, and is stamped accordingly. Premix Technology The burner utilizes Premix technology to mix both gas fuel and combustion air prior to entering the 3

4 MODEL CFLC Features and Benefits burner canister, with air leading during burner firing transitions. Combined with a variable speed fan, this technology provides very low emission levels, exceptionally safe operation, and nearly 100% combustion efficiency. Full Modulation The variable speed fan provides modulated firing for reduced on/off cycling, excellent load tracking, and reduced operating costs. The burner does not require mechanical linkage connections between the fuel input valve and air control. Instead, the microprocessor control positions the fan speed in accordance with system demand, and this determines the fuel input without mechanical device positioning - that is, linkage-less fuel/air ratio control. This eliminates linkage slippage, minimizes burner maintenance, and provides control repeatability. This is shown schematically in Figure 3. Figure 3. Premix Burner Technology Designed For Heating Applications The pressure vessel is designed for 160 psig MAWP (Max. Allowable Working Pressure) and is constructed of durable ASTM Grade Steel and Stainless Steel materials. Figure 4 shows the counter flow heat exchanger design that gives optimal heat transfer. The design also prevents hot spots, does not require a minimum flow for thermal shock protection, and does not require a minimum return water temperature. In fact, the design carries a 20-year thermal shock warranty. Because of its design characteristics, the Model CFLC is well suited for applications utilizing indoor/ outdoor reset controls, radiant floor heating, snow melt systems, ground source heat pump systems and systems that utilize variable speed circulating pumps. It may also be employed in standard hot water systems that require higher heated water at colder outdoor temperatures but then require minimum temperatures during warmer heating days, realizing fuel efficiency savings over traditional hot water boilers. While the design does not lend itself to the direct supply of potable water, a separate storage tank with an internal heat exchanger can be employed, as the microprocessor control permits domestic water programming. Therefore, the Model CFLC can service both hydronic heating and domestic water source heating. Dual Return Two return pipes - high and low temperature - allow condensing performance with as little as 10% return water at condensing temperature. 4

5 MODEL CFLC Product Offering Figure 4. Model CFLC Cutaway View MODEL CFLC PRODUCT OFFERING Information in this section applies to condensing hot water boiler sizes ranging from 4,000,000 BTU input through 12,000,000 BTU input for operation on Natural Gas or LP Gas only. Installation is for indoor use only. Dimensions, ratings, and product information may change due to market requirements and product improvements. Therefore, use this information as a guide. Standard Equipment Equipment des cribed below is for the s tandard boiler offering: 1. The Boiler A. Each boiler size is designed for a Maximum Allowable Working Pressure (MAWP) of 160 psig (11 Bar), constructed in accordance with the ASME Code Section IV and bear the H stamp. Maximum Operating Pressure 144 psig. Maximum Allowable Working Temperature (MAWT) is 250 deg F (121 C); Maximum operating set point temperature 230 deg F (110 C). Minimum supply set point temperature is 130 deg F. There is no minimum return temperature. B. The insulated boiler is mounted on a base and enclosed in a powder coated steel casing. 5

6 MODEL CFLC Product Offering C. One hot water outlet and dual return provided. 2. Boiler Trim and Controls A. The following items are furnished: B. Probe Type Low Water Cutoff control, manual reset. C. High Water Temperature Cutoff, manual reset. D. NTC (negative temp. coefficient) sensor for hot water supply temperature. E. NTC sensor for hot water return temperature. F. ASME Safety Relief Valve 160 psig. (11 Bar) G. Temperature and pressure gauges. 3. Burner Control A. Falcon burner control - an integrated burner management and modulation control with a touch-screen display/operator interface. Its functions include the following: 1. Two (2) heating loops with PID load control. 2. Burner sequencing with safe start check, pre-purge, pilot ignition, and post purge. 3. Electronic ignition. 4. Flame Supervision. 5. Safety shutdown with time-stamped display of lockout condition. 6. Variable speed control of the combustion fan; Variable Speed Drive provided. 7. Supervision of low and high gas pressure, air proving, stack back pressure, high limit, and low water. 8. First-out annunciator. 9. Real-time data trending. 10. (3) pump/auxiliary relay outputs. 11. Modbus communication capability. 12. Outdoor temperature reset. 13. Remote firing rate or setpoint control 14. Setback/time-of-day setpoint 15. Lead/Lag for up to 8 boilers 16. Control circuit transformer B. Variable Speed Drive for combustion air fan 1. Compact packaged unit 2. Factory configured and wired for boiler application 6

7 MODEL CFLC Product Offering FALCON DISPLAY / OPERATOR INTERFACE LWCO RESET DEMAND SWITCH TRANSFORMER, 460/230/208V PRI TRANSFORMER, 115v/25v LWCO CONTROLLER FALCON CONTROLLER IGNITION TRANSFORMER TERMINAL TRACK Figure 5. CFLC Control Panel 4. Forced Draft Burner A. The burner is a Pre-mix design consisting of a unitized venturi, gas valve(s) with safety shutoff and proof-of-closure, blower/motor, and burner head. B. Full modulation is accomplished with a supplied variable speed fan for 5:1 turndown ratio. C. For near flameless combustion, the burner utilizes a Fecralloy-metal fiber head. D. Operating on Natural Gas, NOx emissions will be less than 20 PPM regardless of boiler size and the boiler is certified for California and Texas for Low NOx emissions. E. As an option, the burner is capable of direct vent combustion. F. Ignition of the main flame is by gas pilot, with UV scanner for flame supervision. G. To ensure adequate combustion air is present prior to ignition, and to ensure the fan is operating, a combustion air proving switch is furnished. H. A High Air Pressure Switch is provided to ensure burner lockout in case of excessive back pressure due to a blocked condensate drain or a blocked stack. I. For ease of maintenance and inspection, the blower/motor assembly is furnished with a hinge which permits the assembly to swing away. This provides access to the burner and electrode as well as the tube sheet and tubes. J. Air filter provided as standard. Additional filter media can be ordered. K. VSD-duty TEFC 3-phase tri-voltage motor. 5. Burner Gas Train - The standard gas train is equipped in accordance with culus certification and complies with ASME CSD-1. Each burner gas train includes: A. Low Gas Pressure Interlock, manual reset. B. High Gas Pressure Interlock, manual reset. C. ASME CSD-1 Test Cocks. D. Downstream manual ball type shutoff cock. E. Safety shutoff gas valve(s) with POC. 7

8 DIMENSIONS AND RATINGS Optional Equipment For option details, contact the local authorized Cleaver-Brooks representative. In summary, here are some of the options that can be provided with the boiler: A. Condensate neutralization tank assembly - consists of neutralizing media, filter, and PVC condensate holding tank. B. Direct vent kit for direct vent combustion. C. Outdoor temperature sensor for outdoor reset, frost protection, or warm weather shutdown. D. Header temperature sensor for multiple boiler Lead/Lag operation. E. Auxiliary Low Water Control (shipped loose) for field piping by others into the system piping. F. 100 db Alarm Horn for safety shutdown (replaces standard Falcon alarm). G. Relays for output signal for burner on, fuel valve open. H. Stack thermometer (shipped loose - for field installation by others). I. Stack temperature limit-sensor. J. Auto air vent. K. Boiler drain valve. L. Gas pressure relief valve M. Gas pressure gauge N. Water isolation valves O. Circulating pumps P. Seismic anchoring provisions For options not listed here, consult your authorized Cleaver-Brooks representative. DIMENSIONS AND RATINGS For layout purposes, the overall dimensions for the Model CFLC are shown in Table 1 (US Dimensions) and Table 2 (Metric Dimensions) including the various pipe connection sizes for supply and return water, drain, and vent. The performance ratings for the boiler are shown in Table 3. Altitude Relative to the ratings shown, installation of the boiler above 2000 feet elevation will result in input capacity reduction. Please refer to Table 16 for input ratings of the boiler at various elevations. PERFORMANCE DATA Efficiency The Model CFLC is a full condensing boiler realizing efficiency gain at variable operating conditions. With its true counterflow arrangement and AluFer firetube extended heating surface technology, the CFLC is designed to extract the latent heat of condensation over a greater range than other designs. The nominal point of condensation is approximately 130 F (54.4 C). The ClearFire, due to its more efficient heat transfer design and lower stack temperature, is able to capture the latent heat of condensation over a broader range. Fuel-to-water efficiency is relative to specific operating conditions. The most significant contributing factor for condensing performance is to operate with return water temperatures below 130 F. Operating efficiency will be greater in the condensing mode of operation as noted above, yet with its inherently greater heat transfer surfaces and superior pre-mix burner, the ClearFire s efficiency under traditional non-condensing hot water conditions is also outstanding. Table 4 shows the guaranteed efficiencies at various operating conditions and firing rates for Natural Gas. It should be noted that the efficiency is exceptional at high fire and low fire versus other designs where high efficiency is realized only with low fire or minimal firing rates and low temperature returns. 8

9 PERFORMANCE DATA Figure 6. Model CFLC Dimensional Views 9

10 Table 1. U.S. Standard Dimensions Model CFLC Boiler PERFORMANCE DATA ITEM DIMENSIONS (inches) A Overall Height B Overall Width C Overall Depth D Casing Height F Casing Depth G Gas Connection to Floor H Gas Connection to Boiler Centerline J Gas Connection to Front of Boiler K Air Inlet Venturi to Floor L Air Inlet Centerline to Boiler Centerline M Air Inlet Centerline to Front of Boiler N Stack Connection to Floor P Stack Connection to Boiler Centerline Q Stack Connection to Front of Boiler R Control Panel Projection S Return Connections to Floor T Supply Connection to Floor U Supply Connection to Front of Boiler V Floor to Drain Connection CONNECTIONS (inches) AA Water Return, 150# RF Flg BB Water Supply, 150# RF Flg CC Boiler Air Vent, NPT DD Boiler Drain, NPT 1-1/2 1-1/2 1-1/2 1-1/2 1-1/2 1-1/2 EE Flue Gas, Nominal OD FF Combustion Air Option* 10 or or or or GG Gas Connection, NPT /2 2-1/2 2-1/2 2-1/2 HH Condensate Drain, FPT 1-1/4 1-1/4 1-1/4 1-1/4 1-1/2 1-1/2 JJ Relief Valve 160# Setting 1-1/4 1-1/4 1-1/4 1-1/2 1-1/2 2 CLEARANCES (inches) MM Overhead NN Front PP Rear QQ Side *Direct vent connection size based on duct layout. Contact local C-B representative with questions. Dimensions are approximate. Do not use for construction or installation; refer to appropriate Dimensional Diagram for the specific boiler. 10

11 PERFORMANCE DATA Table 2. Metric Dimensions Model CFLC Boiler ITEM DIMENSIONS (mm) A Overall Height B Overall Width C Overall Depth D Casing Height F Casing Depth G Gas Connection to Floor H Gas Connection to Boiler Centerline J Gas Connection to Front of Boiler K Air Inlet Venturi to Floor L Air Inlet Centerline to Boiler Centerline M Air Inlet Centerline to Front of Boiler N Stack Connection to Floor P Stack Connection to Boiler Centerline Q Stack Connection to Front of Boiler R Control Panel Projection S Return Connections to Floor T Supply Connection to Floor U Supply Connection to Front of Boiler V Floor to Drain Connection CONNECTIONS (inches) AA Water Return, 150# RF Flg BB Water Supply, 150# RF Flg CC Boiler Air Vent, NPT DD Boiler Drain, NPT 1-1/2 1-1/2 1-1/2 1-1/2 1-1/2 1-1/2 EE Flue Gas, Nominal OD FF Combustion Air Option* 10 or or or or GG Gas Connection, NPT /2 2-1/2 2-1/2 2-1/2 HH Condensate Drain, FPT 1-1/4 1-1/4 1-1/4 1-1/4 1-1/2 1-1/2 JJ Relief Valve 160# Setting 1-1/4 1-1/4 1-1/4 1-1/2 1-1/2 2 CLEARANCES (mm) MM Overhead NN Front PP Rear QQ Side *Direct vent connection size based on duct layout. Contact local C-B representative with questions. Dimensions are approximate. Do not use for construction or installation; refer to appropriate Dimensional Diagram for the specific boiler. 11

12 PERFORMANCE DATA Table 3. Model CFLC Boiler Ratings (Sea Level to 2000 Feet) Description Units Input Max. BTU/Hr. 4,000,000 5,000,000 6,000,000 8,000,000 10,000,000 12,000,000 KCAL/Hr. 1,008,000 1,260,000 1,512,000 2,016,000 2,520,000 3,024,000 Natural Gas (1000 Btu/ft3) FT3/Hr Natural Gas M3/Hr Output at 130/80 F [54/27 C] 100% BTU/Hr. 3,760,000 4,700,000 5,640,000 7,520,000 9,400,000 11,280,000 Firing KCAL/Hr. 947,520 1,184,400 1,421,280 1,895,040 2,368,800 2,842,560 BHP KW Output at 180/140 F [82/60 C] 100% BTU/Hr. 3,520,000 4,400,000 5,280,000 7,040,000 8,800,000 10,560,000 Firing KCAL/Hr. 887,040 1,108,800 1,330,560 1,774,080 2,217,600 2,661,120 BHP KW MAWP PSI BAR MAWT F C Operating Temperature, Max. F C Water Content Gallons Liters Weight w/o Water (Shipping) Pounds 7,450 7,800 9,800 10,500 15,300 16,100 Kg Operating Weight Pounds 10,743 10,918 14,460 14,760 22,562 22,928 Kg Fireside Heating Surface ft ,123 1,454 1,885 2,223 m Waterside Heating Surface ft m Standby Heat Loss BTU/Hr 8,000 10,000 12,000 16,000 20,000 24,000 Watts Fan Motor Size 20ppm NOx HP Fan Motor Size 9ppm NOx HP Operating Voltage, Fan A Volts/Ph/Hz 460/3/60 460/3/60 460/3/60 460/3/60 460/3/60 460/3/60 Control Circuit B Volts/Ph/Hz 115/1/60 115/1/60 115/1/60 115/1/60 115/1/60 115/1/60 Incoming Power (Ampacity) Amps Flue Gas Mass 100% Firing lb/hr ,798 9,064 11,330 13,596 (Natural Gas) kg/h Notes: A. Consult Cleaver Brooks for alternate voltage requirements. B. Single point 3-phase power requirement; control circuit transformer is provided as standard 12

13 PERFORMANCE DATA ClearFire Efficiencies The table below, and the series of graphs following it, show the operating efficiencies of each size Model CFLC boiler, including radiation losses. As the Model CFLC is a fully condensing boiler, maximum efficiency is obtained when operating within the condensing mode, utilizing the latent heat of condensation. Table 4. CFLC Efficiencies Return Water Temperature deg F (deg C) Boiler % Firing Size Rate (20) (27) (38) (49) (55) (60) (72) 20% % % % % % % % % % % % % % % % % % % % % % % % Conditions: Natural gas firing 35% excess air Relative Humidity = 50% Combustion air temperature = 80 0 F R & C Loss = 0.2% of rated capacity 13

14 PERFORMANCE DATA Figure 7. CFLC Efficiency Curves % Firing Rate 96 % Firing Rate Efficiency % Efficiency % [15] 80 [27] 100 [38] 120 [49] 140 [60] 160 [72] [15] 80 [27] 100 [38] 120 [49] 140 [60] 160 [72] Return water temperature deg F [C] Return water temperature deg F [C] % Firing Rate 96 % Firing Rate Efficiency % Efficiency % [15] 80 [27] 100 [38] 120 [49] 140 [60] 160 [72] [15] 80 [27] 100 [38] 120 [49] 140 [60] 160 [72] Return water temperature deg F [C] Return water temperature deg F [C] % Firing Rate 96 % Firing Rate Efficiency % Efficiency % [15] 80 [27] 100 [38] 120 [49] 140 [60] 160 [72] [15] 80 [27] 100 [38] 120 [49] 140 [60] 160 [72] Return water temperature deg F [C] Return water temperature deg F [C] 14

15 Emissions Table 5. Model CFLC Boilers: Natural Gas, Estimated Emission Levels POLLUTANT UNITS CO ppm A <10 lb/mmbtu <0.007 NOx SOx HC/VOC PM ppm A <20 B lb/mmbtu <0.024 ppm A <1 lb/mmbtu <0.001 ppm A <4 lb/mmbtu < ppm A - lb/mmbtu <0.01 A. ppm levels are given on a dry volume basis and corrected to 3% oxygen (15% excess air). B. Optional 9 ppm NOx available. Noise Level The Model CFLC is exceptionally quiet at all operating levels, does not require any sound level modifications to provide ultra low noise levels, and is virtually vibration free. Thus, it is very suitable in applications that demand low noise levels. Table 6 shows the noise levels of the CFLC at various firing rates. Table 6. Noise Level (dba) measured 3 feet in front of boiler 20% Firing Rate 50% Firing Rate 100% Firing Rate CFLC CFLC CFLC CFLC CFLC CFLC Boiler Information The Model CFLC boiler is designed for service in any closed hydronic system and can be used to augment any hot water system. It can be put into operation as a single stand-alone unit with 5:1 turndown or in multiple units for larger turndown and capacity. Clearfire boilers may be utilized in water heating systems with no minimum return temperature and supply temperatures from 130 F (55 C) to 230 F (110 C). Because the Clearfire is a full condensing boiler, low return water temperature (below the dewpoint) restrictions do not apply. In fact, the lower the return the better the fuel savings. Variable temperature differentials can be designed to make use of changing outdoor conditions and thus, the Clearfire is not restricted to a nominal 20 F (10 C) differential. The boiler is designed to 15

16 withstand thermal stresses with supply and return temperature differences up to 100 F (55 C; 100% water only), without the use of a boiler-circulating pump, blend pump, or minimum water flow conflicts with the Delta T limit specified earlier. Flow Rates and Pressure Drops To maintain rated capacity of the boiler, recommended flow rates should not be exceeded as the flow will remove the heat beyond the capacity of the boiler. Tables 7 and 8 can be used to determine the full boiler output relative to system temperature drop and the corresponding system pump flow. Knowing the flow rate, the pressure drop through the boiler can be found in Figure 8. Table 7. CFLC Flow Rates* System Temperature Drop Deg F Boiler Size Flow Rate GPM Recommended Flow Rates relative to temperature drop so as not to exceed boiler output capacity *Flow rates based on 94% nominal efficiency Table 8. CFLC Flow Rates* (Metric) System Temperature Drop Deg C Boiler Size Flow Rate m3/hr Recommended Flow Rates relative to temperature drop so as not to exceed boiler output capacity System Operating Parameters To prevent water flashing to steam within the boiler or system, hot water boilers must operate with proper over-pressure. System over-pressure requirements are shown in Table 9. Note: The ASME Code Section IV limits the maximum setting of the excess temperature control to 250 F (121 C) for hot water boilers. This is to ensure that water temperature will not reach the boiling point (steaming) and therefore, so as not to exceed the maximum limit of this control and in compliance with the Code, the operating set point limit of 230 F (110 C) is set for normal boiler operation. While proper overpressure is required, a means to relieve excess pressure at or beyond the design pressure of the boiler must be provided. As boiler water is heated, expansion occurs. And this expansion must be accounted for either with an expansion tank (air filled) or with a bladder type tank. These devices permit the water pressure to expand outside of the boiler and not impact the pressure vessel or pressure relieving device. But, in accordance with Code, each boiler is equipped with an ASME approved safety relieving device should pressure build-up occur. Refer to boiler dimension diagrams for safety relief valve information. Air Venting The elimination of entrained air is required. It is recommended that each unit be piped to an expansion tank. If this is not possible, then an auto air vent should be provided on the vent connection of the boiler. The caveat in using an auto vent is that free oxygen can be introduced to the vessel as the boiler cools, or in some instances the vent can become plugged. The hydronic system, in addition to individual boilers, should be provided with a mechanism for the elimination of air. 16

17 Hot Water Piping The CFLC can be used in primary flow or primary-secondary arrangements. The large water volume firetube design makes the CFLC a low-flow tolerant boiler. Variable speed or on/off pumps may be employed in the piping scheme. Example schematic diagrams of typical hydronic piping systems can be found on the Cleaver-Brooks web site. Table 9. Model CFLC Minimum Over Pressure Requirements (100% water) Outlet Water Temperature Minimum System Pressure ( F) ( C) PSIG Bar

18 CFLC 4000 CFLC 5000 Pressure PSI Pressure PSI Flow rate GPM Flow rate GPM CFLC 6000 CFLC 8000 Pressure PSI Pressure PSI Flow rate GPM Flow rate GPM CFLC CFLC Pressure PSI Pressure PSI Flow rate GPM Figure 8. Waterside Pressure Drop Flow rate GPM 18

19 Water Treatment Cleaver-Brooks ClearFire condensing boilers are suitable for heating systems without significant oxygenation capacity. Systems with continuous oxygenation capacity due to unknown or unseen leaks must be equipped with a system separation or pretreatment device. Closed loop hydronic systems should incorporate air separation, dirt elimination, and air venting. Clean, soft water is generally the best heating medium for filling and make-up water in systems utilizing the Model CFLC. If the water available from the main system is not suitable for use, then demineralization and/or treatment with inhibitors is necessary. Treated filling and make-up water must be checked at least once a year or more frequently if so specified in the application guidelines from the inhibitor manufacturer. Those parts of the boiler in contact with water are manufactured with both ferrous materials and corrosion-resistant stainless steel. The chloride content of the heating water should not exceed 30 ppm and the ph level should be between 8.3 to 10.5 after six weeks of operation. To maintain the boiler's efficiency and prevent overheating of the heating surfaces, the values in Table 10 should not be exceeded. Water make-up during the lifetime of the boiler should not be greater than 3 times the system volume. A water meter should be installed on the makeup line to monitor makeup water volume. Should the system require flushing or cleaning after installation of the CFLC, take care that no particulate matter reaches the boiler during the cleaning process. Note: Corrosion and sludge deposits in old systems must be removed prior to installation of a new boiler. Table 10. Model CFLC Water Chemistry Requirements Parameter Limit Means of control Glycol 25-50% Glycol fill/mixing station ph Buffering agent Nitrates 50 ppm Sulfates 50 ppm Chemical additives Chloride < 250 ppm Oxygen < 0.1 ppm Air separator/eliminator Specific Conductivity < 3500 mmho/cm Total Hardness < 10 ppm Softener Table 11. Model CFLC Water Temperature Data (Non-Glycol) Minimum inlet temp. 33 o F Maximum operating supply set point temp. 230 o F Maximum design temp. 250 o F Minimum supply set point temperature 130 o F Max allowable Delta T 100 o F 19

20 Glycol The Model CFLC boiler may be operated with a solution of glycol and water. Where glycols are added, the system must first be cleaned and flushed. Correct glycol selection and regular monitoring of the in-use concentration and its stability is essential to ensure adequate, long-term freeze protection, as well as protection from the effects of glycol-derived corrosion resulting from glycol degradation. Typically, ethylene glycol is used for freeze protection, but other alternatives exist, such as propylene glycol. Glycol reduces the water-side heat capacity (lower specific heat than 100% water) and can reduce the effective heat transfer to the system. Because of this, design flow rates and pump selections should be sized with this in mind. Generally, corrosion inhibitors are added to glycol systems. However, all glycols tend to oxidize over time in the presence of oxygen, and when heated, form aldehydes, acids, and other oxidation products. Whenever inadequate levels of water treatment buffers and corrosion inhibitors are used, the resulting water glycol mixture ph may be reduced to below 7.0 (frequently reaching 5) and acid corrosion results. Thus, when ph levels drop below 7.0 due to glycol degradation the only alternative is to drain, flush, repassivate, and refill with a new inhibited glycol solution. The following recommendations should be adhered to in applying ClearFire model CFLC boilers to hydronic systems using glycol: 1) Maximum allowable antifreeze proportion (volume%): 50% antifreeze (glycol) 50% water 2) Glycol minimum temperature rating 300 deg F (149 deg C). 3) Maximum allowable boiler outlet/supply temperature: 200 deg F (93 deg C). 4) Minimum water circulation through the boiler: a) The minimum water circulation must be defined in such a way that the temperature difference between the boiler outlet/supply and inlet/return is a maximum of 40 deg F (22 deg C), defined as DT (Delta T). A DT Limit algorithm should be enabled in the boiler controller. b) Independent from the hydraulics of the heating system, constant water circulation through each boiler is required. (Requires a dedicated boiler pump if in a primary/secondary loop arrangement.) Refer to table below for minimum boiler circulation rates. 5) Minimum over-pressure at the boiler: For outlet temperatures up to the maximum of 200 deg F (93 deg C), a minimum operating pressure of 30 psig (2.1 bar) is required. 6) ph level should be maintained between 8.3 and 10.5 Table 12. Glycol Application Guidelines - Model CFLC Minimum required boiler circulation rate (gpm) at maximum firing rate ClearFire System ΔT ( F) Model-Size ΔT = 10 ΔT = 20 ΔT = 30 ΔT = 40 CFLC CFLC CFLC CFLC CFLC CFLC

21 Notes/Limitations: 1. Glycol concentration limit of 25%-50%. Minimum required system operating pressure is 30 psig. 2. Maximum system operating temperature of 200 F. Maximum ΔT of Circulation rates correlate with boiler output based on 92% nominal efficiency. 4. Standard altitude (<2000' ASL). Contact C-B for high altitude applications. 5. Pumps should be sized based on system design ΔT and minimum required flow rates. 6. At minimum firing rate, the minimum circulation rate should correspond to the boiler's turndown. Condensation As the Model CFLC boiler is a full condensing boiler, condensation will develop during startup of a cold boiler or at any time when the return water temperature is below the dew point or approximately 132 F (55.5 C). The condensation collects in the flue gas collection chamber from the tube surfaces and from the stack. As prescribed by local codes, this condensate may be discharged directly to the drain or treated using an optional treatment assembly. Figure 9 depicts piping without the treatment assembly and Figure 10 shows the optional treatment assembly. Table 13 shows the amount of condensation that will form when the boiler operates in full condensing mode. Table 13. Model CFLC Maximum Condensation Boiler Size Gallons per Hour Liters per Hour *Boiler maximum in full condensing mode *Based on 68 F (20 C) return water temperature * ph of The condensate generated during normal boiler operation must be removed in accordance with local codes and regulations. The condensate can be piped to a local treatment system or run into the optional condensate treatment assembly. The water trap must be filled with water prior to commissioning and checked or refilled at each required maintenance interval. The condensate occurring during operation in both the boiler and the flue gas pipeline should be neutralized and piped to a safe drain. The conditions for the discharge of condensates into public drain systems are determined by the local authorities and municipalities. Condensate leaving the boiler normally has a ph of 4-6. The responsible authority will inform you if a higher ph value is required for condensate piped to drain. The CFLC neutralization system contains the granulate NEUTRALAT, a natural compound which acts to increase the ph of the condensate flowing through it. The neutralization system comprises the plastic neutralization tank with condensate inlet, granulate chamber and condensate outlet. 21

22 BOILER REAR WARM WATER RETURN DRAIN COLD WATER RETURN CONDENSATE DRAIN A CONDENSATE TRAP IS PIPED WITHIN THE BOILER. Figure 9. Condensate Piped Direct to Drain Note: To ensure compliance with regulations, it is important to contact the responsible authorities prior to the planning and execution of the boiler installation. Condensate flow of 20 to 80 GPH can be expected depending on boiler size and return water temperature. Condensate tank setup options (1) Condensate direct to drain - The condensate is piped directly to a drain through the piping and water trap supplied during installation (see Figure 9). Piping is to be a minimum of 1-1/4 NPT. (2) Condensate to treatment tank - The condensate is held in a condensate tank(s) under or near the boiler. The condensate is neutralized as it passes through a bed of granular material. The neutralized condensate is then piped to the drain. To install the system, assemble the tank and fittings per instructions supplied with tank. Neutralization media are already installed in tank. For CFLC 4000/5000 the tank must be installed external to the boiler (Figure 10). For sizes the tank(s) may be mounted internally or externally. Install the condensate tank cover and connect tank to boiler condensate discharge. Pipe to an appropriate drain. 22

23 Figure 10. Condensate Treatment Tank - external SIZE SIZES 10,000-12,000 Figure 11. Condensate Treatment Tank - internal The neutralization media will require periodic replacement, to be determined by ph analysis of condensate. If condensate is too acidic (ph is below acceptable value) the neutralization media should be replaced. The number of condensate treatment tanks required depends on the total amount of condensate produced by the system. As a general rule, CB recommends one tank per boiler for sizes 4,000-8,000 and two tanks for sizes 10,000-12,000. Gas Fuel Connections The local Gas Company should be consulted for the requirements for installation and inspection of gas supply piping. Installation of gas supply piping and venting must be in accordance with all 23

24 applicable engineering guidelines and regulatory codes. All connections made to the boiler must be arranged so that all components are accessible for inspection, cleaning, and maintenance. A drip leg should be installed in the supply line before the connection to the boiler. The drip leg should be at least as large as the gas piping connection on the boiler. See Figure 12 and Figure 13 for piping suggestions. TO GAS TRAIN As required As required As required Gas header - size for boiler room capacity and to minimize pressure loss Same or larger than boiler gas connection size Drip leg required for any vertical run of piping Figure 12. Gas Piping Schematic Consideration of volume and pressure requirements must be given when selecting gas supply piping. Connections to the burner gas train must include a union so that the burner may be opened for inspection and maintenance. A. Gas supply connection is at top of the boiler. B. Table 14 shows the gas pressure required at the inlet of the gas line. C. Table 15 shows the correction factors for gas pressure at elevations at 2000 feet and higher above sea level. 24

25 From Meter Gas Header Piping, Typical Header Pipe Manual Shut Off Gas Strainer Regulator See Note 1 Relief Valve See Note 5 NOTES: 1. Dedicated gas pressure regulator required for each boiler if gas supply greater than max. pressure in Table Refer to local fuel gas codes when applicable. 3. Header to be sized for room capacity. 4. Provision required for measuring gas supply pressure at boiler. 5. Overpressure protection required if gas supply pressure > 5 psig. Figure 13. Gas Header Piping 25

26 For proper and safe operation, each CFLC Series boiler requires a stable gas supply pressure. See table below for pressure requirements. Table 14. Model CFLC Minimum and Maximum Gas Pressure Gas Supply Pressure (at gas regulator outlet) Natural Gas 20ppm Natural Gas 9ppm Propane Gas pilot Boiler size Min ( WC) Max* ( WC) Min ( WC) Max* ( WC) Min ( WC) Max ( WC) pressure ( WC) *Listed max. pressures are without the use of a step-down regulator. The CFLC can accommodate higher supply pressures with the addition of an upstream regulator: CFLC >1/2 psig requires step-down regulator >5 psig requires overpressure protection CFLC >2 psig requires step-down regulator >7 psig requires overpressure protection When an upstream regulator is installed, required minimum pressures will be higher due to the pressure drop across the regulator. Actual gas pressure should be measured when the burner is firing using a manometer at the upstream test port connection on the main gas valve. For a multiple unit installation, gas pressure should be set for a single unit first, then the remaining units should be staged on to ensure that gas supply pressure drop is not more than 7" w.c. and never below the required pressure. Fluctuating gas pressure readings could be indicative of a faulty supply regulator or improper gas train piping to the boiler. Refer to Tables 2-6 and 2-7 for gas piping recommendations. To measure pilot gas pressure, use the test port on the pilot solenoid valve. Table 15. Model CFLC Minimum Required Gas Pressure Altitude Correction Altitude in Feet Correction Factor Altitude in Feet Correction Factor To obtain minimum required inlet pressure, select altitude of installation and multiply the pressure shown in Table 15 by the correction factor corresponding to the altitude listed above. 26

27 Table 16. Altitude Correction for Input Capacity at Various Altitude Levels Natural Gas 700' ASL CFLC MBTU/hr CFLC CFLC CFLC CFLC CFLC Ratings assume 35% excess air, 80 F combustion air Blower speed adjustments should be made to match performance and local conditions accordingly. For minimum gas pressure requirements, corrections for altitude should be made per Boiler Book Table 16. Natural gas heating value of 1000 BTU/SCF assumed. Boiler Room Information The boiler must be installed on a level non-combustible surface. If the surface is not level, piers or a raised pad, slightly larger than the length and width of the boiler base dimensions, will make boiler leveling possible. Installing the boiler on a raised pad or piers will make boiler drain connections more accessible and will keep water from splashing onto the boiler whenever the boiler room floor is washed. Note: The pad or piers must be of sufficient load bearing strength to safely support the operating weight of the boiler and any additional equipment installed with it. Approximate operating weights are shown in Dimensions and Ratings. Leveling Once the boiler is placed, it must be leveled side to side and front to back using the supply and return nozzles for horizontal and vertical positions. If shims are required to level the boiler, the weight of the boiler must be evenly distributed at all points of support. Clearances The boiler must be installed so that all components remain accessible. Clearance height above all CFLC boilers is 36.Under special circumstances, alternate clearances may be feasible. Contact your C-B authorized representative for assistance. 27

28 Figure 14. Model CFLC Minimum Room Clearance Dimensions Venting Connections - General Proper installation of flue gas exhaust venting is critical for efficient, reliable, and safe operation of the CFLC boiler. The boiler s appliance category is a major factor determining venting system design. Definitions: Boilers are divided into four categories based on the pressure and temperature produced in the exhaust stack and the likelihood of condensate production in the vent. Category I. A boiler which operates with a non-positive vent static pressure and with a vent gas temperature that avoids excessive condensate production in the vent. Category II. A boiler which operates with a non-positive vent static pressure and with a vent gas temperature that may cause excessive condensate production in the vent. Category III. A boiler which operates with a positive vent pressure and with a vent gas temperature that avoids excessive condensate production in the vent. Category IV. A boiler which operates with a positive vent pressure and with a vent gas temperature that may cause excessive condensate production in the vent. 28

29 Depending on the application, the Model CFLC may be considered Category II, III, or IV. The specifying engineer should dictate flue venting as appropriate to the installation. CFLC condensing applications will typically utilize Category IV venting. For additional information on boiler categorization, see appropriate ANSI Z21 Standard and the latest edition Standard of National Fuel Gas Code or in Canada, the latest edition of CSA Standard B149 Installation Code for Gas Burning Appliances and Equipment, or applicable provisions of local building codes Flue Venting System Design The flue venting should be supported to maintain proper clearances from combustible materials. Flue venting should be supported by the building structure. The maximum load that the boiler flue connection can support is 500 lbs. Use insulated vent pipe spacers where the vent passes through combustible roofs and walls. Vent material should be appropriate for the Appliance Category. Application-specific information will further determine the material selected. For Category II, III & IV appliance categories, Cleaver-Brooks highly recommends that the flue system be Listed to standard UL 1738 Special Gas Vent and be installed in accordance with the National Fuel Gas Code (NFPA 54) or ANSI Z21.47/ CSA 2.3. Type B Vent shall not be allowed for positive pressure (forced draft burner) or condensing vent systems. Draft calculations should be performed for any condensing boiler flue system. It is good practice to perform calculations at several operating conditions to ensure draft tolerances are maintained. For best performance, individual, through-the-roof vertical flue venting is recommended for CFLC boilers. Cleaver-Brooks recommends vertical straight flue (no loss) or velocity cone flue termination. Figure 15. Vent Terminations Note: Traditional rain caps should not be used, as moist, condensing flue gases can be directed downward toward the building and air intakes. In cold climates and freezing ambient temperatures, rain caps can lead to ice formation, air intake blockage, and flue blockage that result from condensing water vapor in the flue gases. 29