Roberts Gorden CoRayVac CRV-B-2 User's Manual
Contents
1. 12 5 2 P mp Capacity elettriche 14 5 3 FlOW rte tette cache 14 SECTION 6 Radiant Tube and 15 6 1 Radiant Tube 15 6 2 15 6 3 Design Parameters 16 6 4 CRV Series Design 16 6 5 Tailpipe Design 18 SECTION 7 Example CRV Series System Layouts 21 7 1 Example System Layout Option 1 21 72 Example System Layout Option 2 22 7 3 Example System Layout Option 3 22 7 4 Example System Layout Option 4 23 7 5 Example System Layout Option 5 23 7 6 Example System Layout Option 6 24 77 Example System Layout Option 7 8 and 9 25 SECTION 8 Control Methods eene 26 8 1 ROBERTS GORDON System Control P N 02770002 sese 26 8 2 ROBERTS GORDON 26 8 3 SPST Transformer Relay P N 90417600 27 8 4 DPST Transformer Relay P N 904363002. 27 8 5 Pressure SWItch iue 27 SECTION 9 Air Supply System 28 9 1 Pressurlzed ice eco 28 9 2 2 28 9 3 Outside Air System Design 28 SECTION 10 ROBERTS GORDON ULTRAVAC Design Requirements eene 31 SECTION 11 CRV Series Equipment Specifications 32 11 1 Burner and Burner 32 11 2 Equipment ier Ei 32 2009 Roberts Gordon LLC All rights reserved No part of this work covered by the copyrights herein may be reproduced or copied in any form or by any means graphic electronic or mechanical including photocopying recording taping or information storage and retrieval systems without the written permission of Roberts Gordon LLC Printed in U S A TABLE FIGURES Figure 1 Assembly Overview Two Branch System Shown 3 Figure 2 Standard 6 Figure 3 One Side 6 Figure 4 Two Side Reflectors 6 Figure 5 Universal Shield Position 1 7 Figure 6 Universal Shield Posit
3. For the end burner the burner inlet flow consists of the end vent air and combustion air For all other Table 1 CORAYVAC Design Parameters burners the burner inlet flow consists the of the total of the end vent air plus the combustion gases from all upstream burners The requirement for minimum burner inlet flow is met if the total flow units entering the combustion chamber meets or exceeds the minimum as shown on Page 12 Table 1 5 1 Radiant Branch Flow The flow in a radiant branch consists of the end vent flow units plus the flow units of combustion air from all burners Page 13 Figure 14 shows a representation of flow units for various types of branches The limiting factor for maximum flow in the radiant sec tion has been determined experimentally in terms of the maximum burner inlet flow units that can be toler ated without degradation of combustion characteris tics at the last downstream burner If more than the maximum number of burners are installed per radiant branch the vacuum loss across the additional burners will increase appreciably This maximum flow in the radiant branch can be expressed for each burner firing rate by either a maxi mum number of burners per branch or the maximum number of flow units See Page 12 Table 1 Burner Model B 2 B 4 B 6 B 8 B 9 B 10 B 12A B 12 Input Btu R x 1000 20 40 60 80 90 100 110 120 Flow Units per Burner 2 4 6 8 9 10 12 12 RE
4. edes 28 Figure 28 Outside Air 29 Figure 29 Sample Layout for Pressurized Outside Air SYSIOMS ficient ete i ee EI aden ete 30 LIST OF TABLES Table 1 CORAYVAC Design Parameters 12 Table 2 Pump 14 Table 3 Pump Exhaust Requirements 14 Table 4 Allowable 17 Table 5 Operating Characteristics Condensing or Non Condensing 18 SECTION 1 CONCEPT The concept of CRV Series is easy to understand However it means discarding old ideas because CRV Series is a different kind of heating system CRV Series is a gas fired vacuum operated low intensity infrared heating system incorporating a pat ented incremental burner system Gas Fired means it uses clean burning Natural or Propane gas Vacuum Operated means that the pump draws all the products of combustion through the system and expels them outdoors Low Intensity means the radiant surfaces of the tubes do not glow red instead they operate at a lower temperature less than 900 F or 482 2 C and radiate heat at lower intensity per square foot of radiating sur face Area coverage is provided by long runs of 4 10 cm O D tubing which hang from the ceiling or roof supports Reflectors direct the radiant heat downward to occupied
5. An air supply free of dust and corrosive contaminants is essential for proper operation and best life expect ancy with any heating system With CRV Series there are two alternatives available to the designer for pro viding the air supply These are Room air a filter is standard for each burner Outside air system to duct air from an uncontami nated source The outside air system can be designed as a pressurized or non pressurized system The first alternative above is usable when the dust load is not excessive and there is no usage of corro sive contaminants such as solvents or vapors inside the building The outside air system must be used in all applica tions where corrosive contaminants may be present in the air even in trace amounts few parts per million It is important for designers and owners of heating systems to note that the presence of contaminants in the combustion air supply will greatly accelerate the rate of corrosion on tube surfaces and will shorten the useful life of the heating system This is true regard less of whether the heating system is CRV Series other infrared systems or conventional gas or oil fired equipment such as unit heaters central boiler plant etc With the unique vacuum powered burners the fuel air mix remains constant even if combustion air filters are dirty It can be expected that the use of an outside air system will reduce but not eliminate the potential for corrosion due
6. 15 m 5 3 Elbows EP 200 Up to 10 3 4 0 Elbows EP 200 Up to 25 7 6 m 5 Elbows EP 200 Up to 50 15 m 6 3 Elbows EP 300 Up to 10 3 m 6 1 Elbows EP 300 Up to 25 7 6 m 7 3 Elbows EP 300 Up to 50 15 m 8 3 Elbows SECTION 6 RADIANT TUBE AND TAILPIPE The main purpose of the tailpipe and the radiant tube is to provide sufficient tube surface to transfer the heat from the flue gases to the tube wall where it radiates from the tube Radiant tube is defined as the tubing between burners firing in a radiant branch plus the radiant tubing immediately following the last down stream burner Tailpipe is defined as all tubing between the radiant tube and the pump Most of the radiant heat supplied by each burner is released from the radiant tube the balance is released by the tailpipe The placement of radiant tube to corre spond to areas of major heat loss is the key to provid ing uniform comfort levels The use of adequate tailpipe is the key to high combustion efficiency and proper operation of the pump 6 1 Radiant Tube Length The considerations in the selection of the length of radiant tube include the following 6 1 1 Minimum Radiant Tube Length Provides for the highest level of intensity per length of radiant tube and good radiant heat uniformity between burners More tailpipe length is required to maintain operating efficiency and pump capacity 6 1 2 Maximum Radiant Tube Length Provides
7. For a single branch system the branch ends at the pump 2 1 Safety Safety is a prime consideration of CRV Series First there is a pre purge of the complete tube network prior to flame ignition Then to ensure that there will be no gas flow unless the pump is operating a pressure switch located at the pump must activate prior to igni tion After the pressure switch has closed there are two valves in series in each burner that must be ener gized as well as a zero regulator Additionally slow opening gas valves provide smooth ignition and enhance reliability Once the thermostat has been sat isfied the burners turn off and the pump continues to run for two minutes to purge the entire system of flue gases With CRV Series all equipment and controls are C S A design certified both as individual parts and also as a complete heating system Also individual electrical component parts are listed as applicable 2 2 Zero Regulator CRV Series uses a 10096 pre mix burner with the input dependent on system vacuum With no vacuum the zero regulator prevents gas flow When vacuum is present the burner fires and input increases as vac uum increases As the input increases the amount of air also increases Over the normal range of operating vacuum the gas air ratio is essentially linear This unique and patented feature provides optimum combustion conditions at all times Combustion condi tions are unaffected by fluctuations in
8. See capacity the following limitations of shared tailpipe Page 12 Table 1 for the rules for each burner apply model See Page 13 Figure 14 for example flow 4 10 cm tailpipe limited to maximum of 2 com unit calculations bined branches and length limited to maximum of Flow Units Per Branch 20 6 m See Page 14 Figure 15 for all other Branch 1 tailpipe considerations Branch 2 Branch 3 6 15 cm tailpipe limited to maximum of 4 com bined branches and length limited to maximum of Seld 100 30 Branch 6 When calculating required tailpipe length 1 3 m of 6 manifold tube is equivalent to 1 3 4 m of 4 Total System tailpipe Flow Units Failure to comply with the above parameters will result 16 4 Select pump model series for total system flow units EP 100 up to 66 flow units EP 200 up to 110 flow units EP 300 up to 224 flow units 5 See Page 14 Table 2 for altitudes greater than 2000 6 For each branch add the length of radiant tube after each heater Radiant Tube Length Burner TT ETAT After Each Burner Total Radiant Tube Length in Branch Repeat this calculation for each branch in the system 7 Divide the total radiant tube length in the branch by the number of burners in the branch to get the average radiant length per burner Average Radiant Length Per Burner Repeat this calculation for each branch in the system 8 Usi
9. cies positively or negatively Page 16 Figure 16 is presented as a guide to the designer for information only NOTE When accounting for the required tailpipe lengths during the design process it is important to verify that the tailpipe for each branch is at least equal to the specified minimum 15 CRV SERIES DESIGN MANUAL FIGURE 16 Tube Length vs Efficiency 3 0 25 5 9 20 6 1 5 5 1 0 83 84 85 86 87 88 89 90 Steady State Thermal Efficiency NOTE Thermal efficiency values shown do not include the contribution due to condensing conditions when operating in cyclic fashion To estimate cyclic efficiencies add 2 396 to the values obtained from the graph 6 3 Design Parameters in insufficient vacuum to burners When designing branches of 4 B 8 or larger burners 6 4 CRV Series Design Methods in series the following limitation to the pump capacity 1 Layout the system to suit the BTU input applies required Pump Model Series Maximum Loading 2 Calculate the system design for each branch EP 100 Not Allowed individually EP 200 1 Branch of 4 burners 3 Calculate the number of flow units per branch of EP 300 2 Branches of 4 burners burners Add the flow units for each branch For systems that are designed above 90 pump together to get the total system flow units
10. radiant heating systems is typically reduced as com pared to the calculated heat loss due to the radiant effects associated with a properly designed radiant heating system The ability of a radiant system to pro vide the advantages of these radiant effects rests largely with the ability of this system to establish a reserve heat capacity in the floor Without this reserve capacity radiant comfort cannot be achieved The exception is station heating spot heating applications where sufficiently high levels of direct radiation are received from the heater The height adjustment fac tor is a means to insure adequate floor level radiant intensity to charge the floor heat reservoir Proportionately larger wall surfaces also remove energy from the floor to a larger degree decreasing the heat reservoir The increased input capacity recommended by a height adjustment factor is not extraneous as com pared to the heat loss calculation Rather it is a real ization that in order to maintain radiant comfort conditions and the economic benefits a minimum radiant level must be maintained at the floor It is recommended that an adjustment to the heat loss of 196 per foot 3 per meter for mounting heights above 20 6 m be added up to 60 18 m Above this height additional correction overstates the BTU requirement as determined by the heat loss EXAMPLE 1 Given a building with a calculated heat loss of 350 000 Btu h wh
11. A B C D CRV B 2 4 20 48 20 11 51 122 51 CRV B 4 4 20 48 20 11 51 122 51 g CRV B 6 4 20 48 20 11 51 122 51 CRV B 8 4 20 48 20 11 51 122 51 CRV B 9 4 36 60 36 11 92 153 92 Y CRV B 10 4 36 60 36 11 92 153 92 CRV B 12 4 36 60 36 11 92 153 92 CRV B 12A 4 36 60 36 11 92 153 92 FIGURE 3 ONE SIDE REFLECTOR inches centimeters Model A B D A B D CRV B 2 4 12 56 20 11 31 143 51 CRV B 4 4 12 56 20 11 31 143 51 CRV B 6 4 12 56 20 11 31 143 51 CRV B 8 4 12 56 20 11 31 143 51 CRV B 9 4 12 60 42 11 31 153 107 CRV B 10 4 12 60 42 11 31 153 107 CRV B 12 4 12 60 42 11 31 153 107 CRV B 12A 4 12 60 42 11 31 153 107 FIGURE 4 TWO SIDE REFLECTORS inches centimeters Model A B D A B D CRV B 2 4 12 56 12 11 31 143 31 CRV B 4 4 12 56 12 11 31 143 31 CRV B 6 4 12 56 12 11 31 143 31 CRV B 8 4 12 56 12 11 31 143 31 CRV B 9 4 12 60 12 11 31 153 31 CRV B 10 4 12 60 12 11 31 153 31 CRV B 12 4 12 60 12 11 31 153 31 CRV B 12A 4 12 60 12 11 31 153 31 SECTION 3 CLEARANCES TO COMBUSTIBLES NOTE 1 All dimensions are from the surfaces of all tubes couplings elbows tees and crosses 2 Clearances and D can be reduced by 50 after 25 7 5 of tubing downstream from where the combustion chamber and the tube connect FIGURE 5 UNIVERSAL SHIELD POSITION 1 inches centimeters Model A B D A B D CRV B 2 4 12 12 12 11 31 31 31 CRV B 4 4 12 12 12 11 31 31 31 CRV B 6 4 12 12 12 11 3
12. CONSIDERATIONS FIGURE 11 Radiant Distribution Average Coverage H mounting height FIGURE 12 Radiant Distribution Increased Coverage mounting height FIGURE 13 Radiant Distribution Heavy Coverage mounting height y height above the floor level where overlap of radiant X 2H 2y output will occur 11 CRV SERIES DESIGN MANUAL SECTION 5 FLOW LOADING The patented CRV Series burner system allows a number of burners to be installed in series in the same radiant tube resulting in a long continuous radi ant emitting surface to give even heat distribution within the building To enable the burners to be correctly located within the system to maintain system operating vacuum and obtain design flue gas temperatures at the pump the design layout is based on a simplified flow principle using a flow unit The flow unit is defined as the amount of fuel air mix ture for a heat input of 10 000 Btu h This corre sponds to a flow rate of 1 83 cfm at 65 70 F For the purpose of design flow units enter the CRV Series system in one of two ways Through the burner Through the end vent plate Flow units exit the system as spent products of com bustion via the pump The purpose of the end vent air is to dilute the hot combustion gases at the burner thereby promoting uniform heating of the tube while avoiding excessive heating of the combustion chamber
13. Eo CRV B 9 4 18 56 18 11 46 143 46 CRV B 10 4 18 56 18 11 46 143 46 CRV B 12 4 18 56 18 11 46 143 46 CRV B 12A 4 18 56 18 11 46 143 46 FIGURE 9 BARRIER SHIELD inches centimeters Model A B C D A B C D A CRV B 2 4 12 12 12 11 31 31 31 A CRV B 4 4 12 12 12 11 31 31 31 Y CRV B 6 4 12 12 12 11 31 31 31 CRV B 8 4 12 12 12 11 31 31 31 vom CRV B 9 UNAPPROVED UNAPPROVED c CRV B 10 UNAPPROVED UNAPPROVED i CRV B 12 UNAPPROVED UNAPPROVED CRV B 12A UNAPPROVED UNAPPROVED FIGURE 10 PROTECTIVE GRILLE inches centimeters Model A B D A B D CRV B 2 4 20 48 20 11 51 122 51 CRV B 4 4 20 48 20 11 51 122 51 CRV B 6 4 20 48 20 11 51 122 51 p pl PE CRV B 8 4 20 48 20 11 51 122 51 CRV B 9 4 36 60 36 11 92 153 92 CRV B 10 4 36 60 36 11 92 153 92 CRV B 12 4 36 60 36 11 92 153 92 CRV B 12A 4 36 60 36 11 92 153 92 SECTION 4 AND DESIGN CONSIDERATIONS SECTION 4 SIZING AND DESIGN CONSIDERATIONS The building heat loss must be calculated in accor dance to accepted energy load calculation methods ASHRAE American Society of Heating Refrigeration and Air Conditioning Engineers offers in depth infor mation that is useful in calculating energy loads The CRV Series system input is determined in concert with the required radiant adjustment to heat loss and height adjustment factors 4 1 Radiant Adjustment to Heat Loss The practice of applying an
14. SERIES DESIGN MANUAL 5 2 Pump Capacity The flow unit capacity of the pump is indicated on Page 14 Table 2 as a function of installed altitude When the CRV Series system is designed in accor dance with this set of instructions and is in proper operating condition a vacuum from 2 3 w c will be obtainable at each end vent i e at all burners Table 2 Pump Capacity There are a number of design requirements which if not met will reduce the vacuum obtainable and thereby the effective flow capacity of the pump These include Minimum Length of Tailpipe If less than the minimum length of tailpipe is provided per radiant branch there will be insufficient cooling of the com bustion gases and improper operation of the pump Line Loss Check for Tailpipe is applicable to sections of tailpipe which are common to two or more radiant branches i e shared lengths See Page 14 Figure 15 Excessive back pressure on discharge line of pump can be caused by partial blockage or too much flow for length See Section 5 3 1 More than maximum number of burners or flow units per radiant branch See Page 14 Table 2 Excessive number of elbow or tee fittings which increases vacuum loss 5 3 Tailpipe Flow Excessive flow loading in a single section of tailpipe can cause low vacuum and lower effective pump capacity For the pump to develop the proper vacuum the length of tailpipe must not b
15. adjustment factor to heat loss calculations for radiant heating systems is well known within the radiant heating industry having been used by manufacturers for over 25 years A number of studies have been conducted to identify the values of the adjustment factor in the range of 0 8 to 0 85 depending on efficiency higher efficiency uses lower factor This adjustment can be more thoroughly understood when considering the following radiant effect issues Infrared energy heats objects not the air Lower ambient temperatures reduce the amount of air infiltration Less air stratification with radiant heat Lower ambient air temperatures reduce the trans mission heat loss through walls and roof Elevated floor temperature provides a thermal reserve capacity Increased mean radiant temperature allows occu pants to perceive thermal comfort at the reduced air temperature Each of these issues impacts favorably on the reduc tion of the installed capacity of the radiant heating sys tem This fact together with the realization that the standard ASHRAE heat loss calculation methods particularly the transmission heat loss coefficients have been developed specifically for conventional hot air systems demonstrates the need for the heat loss adjustment factor In general a 80 adjustment factor should be used for CRV Series systems 4 2 Radiant Height Adjustment Factor As discussed above the installed input capacity of
16. areas Radiant refers to the heat radiated by the CRV Series system Because this heat is in the form of infrared rays it does not directly heat the air Instead the rays heat objects such as floors people walls cars machines tools etc The warm objects in turn heat the air through convection Incremental Burner System means that several burners can operate in series and fire into the same run of steel tube that carries the combustion gases from upstream burners Each of these burners in a radiant branch may have different firing rates also the space between burners may vary This allows the designer to match heat gain to heat loss for each area of the building Firing burners in series provides higher thermal and radiant efficiency In a properly designed low intensity radiant system the occupants should be barely aware of the radiant heat when the system is firing They will feel little or no change when the thermostat is satisfied and the sys tem is not firing This combines with warm floors warm walls and draft free operation to improve the mean radiant temperature of the space This is the key to the exceptional comfort and fuel efficiency provided by the CRV Series system SECTION 1 CONCEPT CRV SERIES DESIGN MANUAL SECTION 2 THE CRV SERIES SYSTEM A CRV Series system consists of one pump a control system and a number of burners see Page 3 Figure 1 It also includes an extended tube surface 4 10 cm stee
17. fuel pressure vacuum dirty air filters changes in atmospheric pres sure wind velocity or other climate conditions SECTION2 THE CRV SERIES Assembly Overview Two Branch System Shown FIGURE 1 o sneyxg eq edidjre edidjrey pue 12 pesn 10 jenbeuf seuoueJq seu 1no e 72 eaS peziuiunje Jo 10d eq snu 1991 peziuiunje JO 9 1 j euuiou s 152 99 JO 91 9 06 02 pue sieuinq Bulgn jueIpey 1 f Buyydnog eqnr ueipeH JequieuS uonsnquio2 young SUUS P D Sap pua BC Ts Ne SS pug gt J j0joo Jod 1 saung C Jeuung pug CRV SERIES DESIGN MANUAL 2 3 Fuel Savings and Comfort Space heating can be accomplished with l
18. model to ensure that result ing tailpipe lengths maintain intended operating char acteristic 6 5 5 Damper Couplings Damper couplings are needed n any tailpipe branch that carries less flow units than other tailpipe branches connected to the same pump unsymmetrical layouts with branches having the same number of flow units the damper cou pling is placed in every branch except for the longest branch The purpose of the damper coupling is to adjust the end vent vacuum down to the desired level These are to be placed in the tailpipe section and not the radiant branch The recommended location is before the first tee fitting or 10 40 from the end of the radiant pipe See Page 20 Figure 17 Page 23 Figure 21 Page 24 Figure 25 and Page 25 Figure 26 for placement examples SECTION 6 RADIANT TUBE AND TAILPIPE 19 CRV SERIES DESIGN MANUAL FIGURE 17 Possible Damper Coupling Locations 7 3 2 7 A pug 7 07 I Jedureq euoz a LON 20 SECTION 7 EXAMPLE CRV SERIES SYSTEM LAYOUTS SECTION 7 EXAMPLE CRV SERIES SYSTEM LAYOUTS Systems that are symmetrical are preferred because the vacuum available in the system branches are bal anced as a function of design damper couplings are not Where radia
19. to contamination In a way similar to the CRV Series pump system the design of the air supply system also involves consider ations of total flow units and acceptable combinations of duct lengths and diameters versus flow units car ried In certain circumstances it may be desirable to introduce an outside air blower to pressurize the sys tem A small positive pressure is desirable and neces sary to prevent the system from drawing in contaminated air 9 1 Pressurized For pressurized outside air supplies the outside air blower motor has a pressure switch that must be used Wire this switch in series with the pump pressure switch When using an outside air blower with a ROB ERTS GORDON System Control ROBERTS GOR 28 DON ULTRAVAC or relay transformer a separate load relay package is required Wire the control for the relay in parallel with the pump The outside air blower must have a separate 20 A 120 V power supply 9 2 Non Pressurized For a non pressurized outside air supply a 4 O D sin gle wall pipe duct may be attached to the burner and end vent For length and duct sizing requirements See Section 9 3 To prevent condensation insulate the outside air duct 9 3 Outside Air System Design Requirements 9 3 1 Non Pressurized 6 diameter duct must not exceed 90 27 m 4 diameter duct must not exceed 90 27 m Elbows are equivalent to 10 3 m of duct length See the CRV Series Installation Operation and Ser
20. 1 31 31 CRV B 8 4 12 12 12 11 31 31 31 CRV B 9 8 18 24 18 21 46 61 46 CRV B 10 8 18 24 18 21 46 61 46 CRV B 12 8 18 24 18 21 46 61 46 CRV B 12A 8 18 24 18 21 46 61 46 FIGURE 6 UNIVERSAL SHIELD POSITION 2 inches centimeters Model A B C D A B C D CRV B 2 4 24 48 24 11 61 122 61 CRV B 4 4 24 48 24 11 61 122 61 CRV B 6 4 24 48 24 11 61 122 61 CRV B 8 4 24 48 24 11 61 122 61 CRV B 9 4 36 48 36 11 92 122 92 CRV B 10 4 36 48 36 11 92 122 92 CRV B 12 4 36 48 36 11 92 122 92 CRV B 12A 4 36 48 36 11 92 122 92 FIGURE 7 UNIVERSAL SHIELD POSITION 3 inches centimeters Model A B D A B D CRV B 2 4 12 56 30 11 31 143 77 CRV B 4 4 12 56 30 11 31 143 77 CRV B 6 4 12 56 30 11 31 143 77 CRV B 8 4 12 56 30 11 31 143 77 CRV B 9 8 12 60 42 21 21 153 107 i CRV B 10 8 12 60 42 21 31 153 107 CRV B 12 8 12 60 42 21 31 153 107 CRV B 12A 8 12 60 42 21 31 153 107 CRV SERIES DESIGN MANUAL NOTE 1 All dimensions from the surfaces of all tubes couplings elbows tees and crosses 2 Clearances B C and D can be reduced by 50 after 25 7 5 m of tubing downstream from where the combustion chamber and the tube connect FIGURE 8 2 FOOT DECO GRILLE inches centimeters Model A B D A B D CRV B 2 4 12 48 12 11 31 122 31 CRV B 4 4 12 48 12 11 31 122 31 CRV B 6 4 12 48 12 11 31 122 31 CRV B 8 4 12 48 12 11 31 122 31 c
21. 2 combustion chamber 8 ae 50 i 20 gt Maximum Number of Burners per Branch 6 4 4 4 2 4 3 3 Maximum Number of Flow Units per Branch 18 26 39 52 33 60 56 56 Radiant Tube Length average distance between burners Minimum ft 10 12 5 20 20 20 30 35 35 Recommended ft 15 20 25 30 30 40 50 50 Maximum ft 20 25 85 45 50 60 70 70 Minimum Distance from Burner to Downstream Elbow ft 5 5 10 10 10 15 15 15 Suggested Minimum mounting Height ft 8 8 8 10 10 15 15 15 CRV 9 requires first downstream tube from burner to be aluminized heat treated 12 SECTION 5 FLow LOADING FIGURE 14 Burner Flow Units E Burner 1 Total Flow 10 2 10 3 Units End Vent Air Downstream Burner Downstream Burner BIG M i ow Units r Combustion Gas r Combustion Gas r Combustion Gas 10 Flow Units 10 Flow Units 10 Flow Units Coupling Burner 55 Burner Firing Rate Burner 1 Burner 2 Burner 43 Total Flow Btu h Flow Units Flow Units Flow Units Flow Units Units 5 TT gt Daan E 60 000 gt i 80 000 100 000 100 000 100 000 120 000 110 000 120 000 110 000 20 gt 5 120 000 110 000 120 000 100 000 gt C 80 000 13 CRV
22. CRV Series systems using the ROBERTS GORDON ULTRA VAC Controller See Page 31 Section 10 SECTION 8 CoNTROL METHODS Buildings today demand all sorts of control options indication of operating conditions The transformer based on the user s preference ULTRAVAC relay wiring diagram is shown in the CORAYVAC controls offer a host of communication options for Installation Operation and Service Manual P N integration with controls networks to best serve 127102NA individual needs BACnet Interface ULTRAVAC with other building management control platforms with our BACnet A pressure switch is required to confirm pump opera option tion on all systems TCP IP LAN Connect to ULTRAVAC via your local area network of computers Load ULTRAVAC software onto any computer on the network and control and view your heating system from your computer Dial into ULTRAVAC from anywhere the world via modem Supplied as standard on all central controllers RS 485 Hard wire ULTRAVAC directly to your computer There are references in this manual to various trademarks All trademarks mentioned herein whether registered or not are the property of their respective owners Roberts Gordon is not sponsored by or affiliated with any of the trademark or registered trademark owners and make no representations about them their owners their products or services Roberts Gordon LLC is not sponsored by or affiliated
23. EP 200 Series pump Layout to provide high system efficiency condensed radiant output and good uniformity of distribution Adjust the lengths as necessary for different input sys tems and to change the efficiency levels 24 This layout method is often used effectively in heatloss and perimeter heating applications FIGURE 24 Example System Layout Option 7 X 07 30 9 Y 180 9 55 l 30 negligible 9 m FIGURE 25 Example System Layout Option 8 30 9 m lt gt 30 lt 10 3 FIGURE 26 Example System Layout Option 9 SECTION 7 EXAMPLE CRV SERIES SYSTEM LAYOUTS Layout to provide condensed radiant output and good 30 9 m 30 9 m 2d 3m 9 m 5 7m1 l io 1 3 ve n Tailpipe 30 9 30 9 7 7 Example System Layout Option 7 8 and 9 These systems are for B9 burners only this burner is specially rated for 2 burners in series applications in the systems shown Option 7 is a 180 55 m straight system connected to an EP 100 pump Option 8 is a system connected to an EP 200 Series pump Option 9 is a system connected to an EP 300 Series pump These layouts show minimum allowed lengths Addi tional tubing may be added The distance between the burners can be varied from 30 9
24. If these lay outs are not suitable it is necessary to customize the layout for the CRV Series system to the individual building requirements For multiple branch systems always plan to connect the unshared tailpipe together as close to the pump as possible for better system efficiency 6 5 2 Shared Tailpipe Calculation System with EP 100 or EP 200 Series Pump See Page 14 Figure 15 for maximum permissible length of tailpipe for the number of flow units entering 18 the section of tailpipe If flow units entering a shared tailpipe system exceed 90 of pump capacity the length of 4 diameter tailpipe must not exceed 20 System with EP 300 Series Pump For shared tailpipe up to 115 flow units 4 diameter tailpipe can be used See Page 14 Figure 15 for max imum permissible length of tailpipe for the number of flow units entering the section of tailpipe Shared tailpipe greater than 115 flow units use 6 diameter tube Note that all tailpipe lengths for the pur poses of calculation are expressed in terms of 4 diameter tube Effective length 10 3 m of 6 15 cm diameter tube 13 4 m of 4 diameter tube 6 5 3 To Calculate the Total System Tailpipe Total unshared tailpipe shared 4 branch tailpipe effective length of shared 6 6 5 4 To Check Performance Criteria Total system tailpipe Total flow units Tailpipe ft flow unit Compare the results to Page 17 Table 4 and Page 18 Table 5 for the burner
25. ROBERTS GORDON CoRaulac Custom Engineered Gas Fired Low Intensity Infrared Heating System CRV B 2 CRV B 9 CRV B 4 CRV B 10 CRV B 6 CRV B 12 CRV B 8 CRV B 12A Design Manual designs must be installed in strict accordance with the CORAYVAC Installation Operation and Service Manual P N 127102NA Roberts Gordon LLC 1250 William Street Box 44 Buffalo New York 14240 0044 Telephone 716 852 4400 Fax 716 852 0854 Toll Free 800 828 7450 WWW rg inc com www radiantheaters com 2009 Roberts Gordon LLC Www corayvac com P N 127500NA Rev D 05 09 TABLE CONTENTS ii EAR 1 SECTION 2 The CRV Series 2 2 1 2 2 2 Zero 2 2 3 Fuel Savings and Comfort 4 SECTION 3 Clearances to Combustibles 5 3 1 Required Clearances to Combustibles 5 SECTION 4 Sizing and Design Considerations 9 4 1 Radiant Adjustment to Heat LOSS 9 4 2 Radiant Height Adjustment Factor 9 4 3 Selecting the 10 4 4 Radiant Distribution 10 SECTION 5 Flow Loading ener 12 5 1 Radiant Branch FIOW
26. RV SERIES DESIGN MANUAL SECTION 11 CRV SERIES EQUIPMENT SPECIFICATIONS The total heating system supplied shall be design cer tified by the CSA International per American National Standard ANSI 783 20 2 34 latest edition 11 1 Burner and Burner Controls 11 1 1 Burners shall be designed to operate simulta neously in series without adverse effects from com bustion gases from upstream burners 11 1 2 Burners shall be capable of firing on Natural Gas or LP Gas 11 1 3 Burners shall be supplied to fire at any one of the input firing rates as specified CRV B 2 20 000 Btu h CRV B 4 40 000 Btu h CRV B 6 60 000 Btu h CRV B 8 80 000 Btu h CRV B 9 90 000 Btu h CRV B 10 100 000 Btu h CRV B 12A 110 000 Btu h CRV B 12 120 000 Btu h When using ROBERTS GORDON ULTRAVAC con trols burner rates will modulate between 6096 and 100 rated input CRV B 2 and CRV B 4 are not avail able for use with ROBERTS GORDON ULTRAVAC controls 11 1 4 The design of burners supplied shall provide for maintaining a constant proportion of fuel gas to fil tered combustion air These conditions are met for burners in which the pressure of both the fuel gas and the combustion air are introduced at zero atmo spheric pressure and the flow of each is established by a vacuum on the downstream side of the flow metering orifices 11 1 5 To assure a high degree of fail safe operation the design shall preclude flow of gas if any or all o
27. actor conduct at a minimum annual inspections of your ROBERTS GORDON equipment and perform service where necessary using only replacement parts sold and supplied by Roberts Gordon Further Information Applications engineering and detailed guidance on systems design installation and equipment performance is available through ROBERTS GORDON representatives Please contact us for any further information you may require including the Installation Operation and Service Manual This product is not for residential use 2009 Roberts Gordon LLC All rights reserved No part of this work covered by the copyrights herein may be reproduced or copied in any form or by any means graphic electronic or mechanical including photocopying recording taping or information storage and retrieval systems without written permission of Roberts Gordon LLC WWW rg inc com Printed in U S A P N 91037912 Rev H
28. at is the installed capacity required of a CORAYVAC system mounted at 30 9 m Installed Capacity Heat Loss x Radiant Adjustment x Height Adjustment For CORAYVAC systems a 80 radiant adjust ment factor is used The height adjustment is 1 per foot over 20 396 per meter over 6 meters or 1 10 CORAYVAC Installed Capacity 350 000 Btu h x 80 x 1 10 308 000 Btu h A 12 reduction in installed capacity vs a conventional heating system CRV SERIES DESIGN MANUAL EXAMPLE 2 Given a building with a calculated heat loss of 500 000 Btu h what is the installed capac ity required of a CRV Series system mounted at 50 15 m CORAY VAC Installed Capacity Heat Loss x Radiant Adjustment x Height Adjustment For CORAYVAC systems a 80 radiant adjust ment factor is used The height adjustment is 1 per foot over 20 396 per meter over 6 meters or 1 30 CORAYVAC Installed Capacity 500 000 Btu h x 80 x 1 30 520 000 Btu h Note in Example 2 if equipment had been convention ally sized based on thermal output only a nearly iden tical input requirement would result For mounting heights above 60 18 m no further correction is gen erally necessary if the floor level radiant intensity is sufficient to establish a reserve capacity hence radi ant comfort and the heat loss requirement is satisfied based on thermal output Due to the complexity of i
29. at section Duct Design Rules System should be designed so that the blower is positioned closest to the highest flow require ments end vents When a duct is carrying more than 40 flow units it must be at least 6 diameter Blower P N 90707501 Performance 112 Flow Units One outside air blower is required per each EP 100 or EP 200 series pump and two outside air blowers may be required for each EP 300 series pump Outside air blowers cannot be shared between two separate CRV Series systems FIGURE 28 Outside Air Blower SECTION 9 AIR SUPPLY SYSTEM 29 CRV SERIES DESIGN MANUAL FIGURE 29 Sample Layout for Pressurized Outside Air Systems lt NOTE up to 10 3 m from blower 6 Duct inlet can be neglected for pressure drop 4 Duct calculations ue 30 SECTION 10 ROBERTS GORDON ULTRAVAC DESIGN REQUIREMENTS SECTION 10 ROBERTS GORDON ULTRAVAC DESIGN REQUIREMENTS CRV B 2 and CRV B 4 are not available for use with ROBERTS GORDON ULTRAVAC controls CRV Series systems designed with minimum radiant tube lengthshall have 1 5 2 0 per flow unit of tailpipe length OR CRV Series systems with recommended radiant tube length shall have 1 2 1 5 per flow unit of tailpipe length 31 C
30. celain All heat exchanger tubing connections shall be made with stainless steel coupling assemblies Standard couplings will be used in radiant sections Lined cou plings will be used in tailpipe sections 11 2 4 Outside Air When specified in contaminated environments the system shall be capable of supplying air from the out side to each burner and end vent for the support of combustion Attach this information to wall near the ROBERTS GORDON heater ROBERTS GORDON Infrared Heating Read the Installation Operation and Service Manual thoroughly before installation operation or service Know your model number and installed configuration Model number and installed configuration are found on the burner and in the Installation Operation and Service Manual Write the largest clearance dimensions with permanent ink according to your model number and configuration in the open spaces below OPERATING INSTRUCTIONS 1 STOP Read all safety instructions on this information sheet 2 Open the manual gas valve in the heater supply line 3 Turn on electric power to the heater 4 Set the thermostat to desired setting TO TURN OFF THE HEATER 1 Set the thermostat to off or the lowest setting Fire Hazard IF THE HEATER WILL NOT OPERATE TO ENSURE YOUR SAFETY FOLLOW THESE INSTRUCTIONS TO SHUT DOWN YOUR HEATER Keep all flammable objects liquids and vapors the minimum required clearances to combustibles away from heat
31. e excessive for the 14 Installed Altitude Maximum Flow Units Feet Above Meters Above pp 00 EP 200 EP 300 Sea Level Sea Level Series Series 0 2000 0m 609m 66 112 224 2001 3000 610m 914m 63 105 215 3001 4000 915 1219 60 100 206 4001 5000 1220 m 1524 57 95 197 5001 6000 1525 m 1828 m 54 90 188 6001 7000 1829 2134 51 84 180 7001 8000 2135 m 2438 48 80 170 8001 9000 2439 m 2743 m 45 75 161 number of flow units carried the tube See Figure 15 Readings for length and flow when plotted on the graph must fall on OK side to avoid excessive vacuum losses FIGURE 15 Vacuum Loss Curve for 4 Shared Tailpipe 130 Length of Tailpipe Section feet 100 110 120 0 30 40 50 60 70 80 90 Maximum Flow Units per Single Tailpipe Section NOTE For 6 15 m tailpipe length is limited to a maximum of 100 30 m See Page 16 Section 6 3 for more details Lengths shown include allowance for 1 elbow every 50 15 m deduct 15 of length for each additional elbow used per 50 15 m length 5 3 1 Pump Exhaust Length Requirements The tube length on the exhaust side of the pump is considered excessive if not within the following condi tions Table 3 Pump Exhaust Requirements Pump Series Exhaust Tube Length Exhaust Tube Diameter EP 100 Up to 25 7 6 m 4 3 Elbows EP 100 Up to 50
32. ects must be away from the heater to prevent serious fire hazards Combustibles are materials which may catch on fire and include common items such as wood paper rubber fabric etc Maintain clearances to combustibles at all times for safety Clearances for all heater models are located on the burner assembly and on Page 6 Figure 3 through Page 8 Figure 10 in this manual Check the clear ances on each burner for the model heater being installed to make sure the product is suitable for your application and the clearances are maintained Read and follow the safety guidelines below Keep gasoline or other combustible materials including flammable objects liquids dust or vapors away from this heater or any other appli ance The stated clearances to combustibles represents a surface temperature of 90 F 32 C above room temperature Building materials with a low heat tolerance such as plastics vinyl siding can vas tri ply etc may be subject to degradation at lower temperatures It is the installer s responsibil ity to assure that adjacent materials are protected from degradation Maintain clearances from heat sensitive equipment and workstations Maintain clearances from vehicles parked below the heater Maintain clearances from swinging and overhead doors overhead cranes vehicle lifts partitions storage racks hoists building construction etc In locations used for the storage of combustible materials sig
33. er Set the thermostat to off or the lowest setting Some objects will catch fire or explode when placed close to Turn off electric power to the heater heater Turn off the manual gas valve in the heater supply line ils i 4 pid Failure to follow these instructions can result in death injury installation and service gas lire eaung equipment or property damage Maintain clearance to the side and clearance below the heater from vehicles and combustible materials Roberts Gordon LLC Roberts Gordon Europe Limited Service Telephone 44 0 121 506 7709 1250 William Street Unit A Kings Hill Business Park Service Fax 44 0 121 506 7702 P O Box 44 Darlaston oad Wednesbury E mail uksales 9 rg inc com Buffalo NY 14240 0044 USA Wes Midlands WS10 7SH UK E mail export 9 rg inc com Telephone 716 852 4400 Slephone 144 01212067700 44 0 121 506 7701 716 852 0854 Toll Free 800 828 7450 Installation Code and Annual Inspections All installation and service of ROBERTS GORDON equipment must be performed by a contractor qualified in the installation and service of equipment sold and supplied by Roberts Gordon and conform to all requirements set forth in the ROBERTS GORDON manuals and all applicable governmental authorities pertaining to the installation service and operation of the equipment To help facilitate optimum performance and safety Roberts Gordon recommends that a qualified contr
34. ess input capacity when a radiant heating system is utilized rather than with a conventional convective heating system Why is this so A conventional convective heating system such as a unit heater or central furnace works by heating the air which then indirectly heats the area and occupants CRV Series utilizes infrared energy to heat objects people and surfaces directly not the air The warm objects and floor create a heat reservoir which then re radiates to the surroundings and also heats the air by convection The radiant energy received by the occupants directly from the heater or indirectly from the surroundings via re radiation serves to increase the mean radiant temperature MRT of the space In a manner similar to direct sunlight the increased MRT allows the occupant to perceive a comfort condition at a reduced air temperature The resulting reduced air temperature within the space provides the following fuel saving advantages Reduced stratification of air in the space Reduced transmission heat loss due to lower tem perature inside than assumed design condition Reduced air change heat loss to the extent that exfiltration through cracks or openings near the roof will be decreased because of decreased stack effect Decreases the actual degree days experienced SECTION 3 CLEARANCES TO COMBUSTIBLES 3 1 Required Clearances to Combustibles Clearances are the required distances that combusti ble obj
35. f the following abnormal conditions occur in the non firing mode 1 Main valve fails in open position 2 Vacuum pump motor fails to operate 3 Power fails 11 1 6 To further assure a high degree of safety the system will be under negative pressure at all times during operation to preclude the possibility of the escape of combustion gases inside the building 11 1 7 The burner control assembly will include a zero regulator 11 1 8 All burners shall be pre wired with a grounded electrical cord and plug 32 11 2 Equipment 11 2 1 Burner Each burner assembly shall consist of heavy duty cast iron burner heads pre wired gas controls with electronic three try direct spark ignition and combus tion air filter 11 2 2 Pump The pump model supplied will vary with the capacity of the system See the pump technical specification sheet or the installation operation and service manual for product description and specification The pump shall be acoustically isolated from the sys tem with a flexible connector with temperature rating of 350 F minimum The motor in the vacuum pump shall be secured with rubber mounts for acoustical isolation 11 2 3 Heat Exchanger Radiant tubing between burners and 10 70 down stream of last burner shall be of 4 O D steel or heat treated aluminized tubing As an option the balance of the tubing shall be 4 O D steel tubing with an internal and external coating of acid resistant por
36. ferent input sys tems and to change the efficiency levels 21 CRV SERIES DESIGN MANUAL FIGURE 20 Example System Layout Option 3 FIGURE 19 Example System Layout Option 2 40 40 12 12 m 10 3m q peat T 12m 40 12 m 40 12m 7 2 Example System Layout Option 2 Six B10 burners at recommended radiant tube length 1 2 flow unit tailpipe the recommended pump for this system is an EP 200 Series pump Layout will minimize up front equipment cost of tubing by implementing minimum tailpipe length Layout will exhibit minimum system efficiency Adjust the lengths as necessary for different input systems and to increase the efficiency levels 22 30 9 30 9 lt 40 12m 6 Tailpipe 50 15m 7 3 Example System Layout Option 3 Twelve B10 burners at minimum radiant tube length and 1 56 flow unit tailpipe the pump for this system is an EP 300 Series Pump All shared tailpipe is 6 diameter Layout will provide maximum radiant intensity between burners Layout will exhibit minimum system efficiency Adjust the lengths as necessary for different input systems and to increase the efficiency levels FIGURE 21 Example System Layout Option 4 SECTION 7 EXAMPLE CRV SERIES SYSTEM LAYOUTS FIGURE 22 Example System Layout Option 5 30 I lt 6 Tailpipe 9m I 7 4 E
37. he aim of this distribution is to provide average or lighter than average radiant intensity and works well for general building heating See Page 11 Figure 11 The distance between radiant branches can vary between 2 5 to 4 or more times the mounting height This distribution is commonly used in applications such as warehouses and lower heat loss areas of a building Lighter coverage can be used in areas where occu pant traffic is low 4 4 2 Radiant Distribution Increased Coverage The aim of this distribution is to provide continuous radiant intensity See Page 11 Figure 12 The distance between radiant branches is about 2 times the mounting height This distribution is commonly used in areas bordering high heat loss areas or areas requiring increased radi ant intensity to achieve occupant comfort 4 4 3 Radiant Distribution Heavy Coverage The aim of this distribution is to provide increased radi ant intensity in areas that range from sedentary work to spot heating for loading docks See Page 11 Figure 13 The y dimensions in the diagram is the height above floor level where overlap of the radiant output will occur In practice y 6 1 83 m is commonly used in areas where occupant comfort doing sedentary work is an important factor In loading bays spot heating and areas of high heat loss the horizontal distance x between branches can be as little as 0 5 times the mounting height SECTION 4 SIZING AND DESIGN
38. ion 2 7 Figure 7 Universal Shield Position 3 7 Figure 8 2 Foot Deco 8 Figure 9 Barrier Figure 10 Protective Grille Figure 11 Radiant Distribution Average Coverage 11 Figure 12 Radiant Distribution Increased Coverage 11 Figure 13 Radiant Distribution Heavy 11 Figure 14 Burner Flow 2 2 2 13 Figure 15 Vacuum Loss Curve for 4 Shared Tailpipe 14 Figure 16 Tube Length vs 16 Figure 17 Possible Damper Coupling Locations 20 Figure 18 Example System Layout Option 1 21 Figure 19 Example System Layout Option 2 22 Figure 20 Example System Layout Option 3 22 Figure 21 Example System Layout Option 4 23 Figure 22 Example System Layout Option 5 23 Figure 23 Example System Layout Option 6 24 Figure 24 Example System Layout Option 7 24 Figure 25 Example System Layout Option 8 24 Figure 26 Example System Layout Option 9 25 Figure 27 Air Supply System Capacity by Duct Length and 2
39. l tubing covered by highly efficient reflectors to direct the radiant heat downward to the floor The tubing nearest the burners radiates with the most intensity and is called radiant tube This should be located over areas with the greatest heat loss The rest of the tubing surface located between the radiant tube and the pump radiates with less intensity and is called tailpipe This can be located in areas with lower heat loss While it is important to locate radiant tubes over areas with high heat loss such as the perimeter of the build ing it is not essential to cover all areas directly with radiant heat Center areas away from external walls and other areas of low heat loss can be adequately heated without direct coverage as long as the input of the system is adequate for the total building heat loss However to achieve the highest degree of comfort and fuel savings it is recommended that the CRV Series system be located to provide as complete and even a distribution as is practical In addition several different reflector and shield configurations are available to direct the radiant heat to or away from desired areas Page 3 Figure 1 illustrates the components of a typi cal CRV Series system The system shown is a four burner system composed of two branches A branch consists of a single run of tubing including an end burner followed by any burners downstream A branch ends at a tee or a cross where other branches connect
40. m to 20 6 m but the overall system lengths must remain the same Layout will minimize upfront equipment cost of tubing by implementing special shortened minimum tailpipe lengths uniformity of distribution Layout will exhibit minimum system efficiency 25 CRV SERIES DESIGN MANUAL SECTION 8 CONTROL METHODS DANGER Electrical Shock Hazard Disconnect electric before service or maintenance More than one disconnect switch may be required to disconnect electric to the unit Control must be properly grounded to an electrical source Failure to follow these instructions can result in death or electrical shock A WARNING Explosion Hazard Turn off gas supply to heater before service Failure to follow these instructions can result in death injury or property damage There are several methods of controlling CRV Series systems The options are as follows 8 1 ROBERTS GORDON System Control P N 02770002 The ROBERTS GORDON System Control is an electronic controller designed for the control of CORAYVAC VANTAGE NP multiburner only systems The System Control is capable of giving four zones of burners temperature control and power The control will also give power output to as many as two pumps provided that the load is not greater than 20 A and 1 For additional electrical specifications see the System Control Installation Operation and Service manual P N 10091601NA 26 Elec
41. ng the average radiant length per burner Calculated in Step 7 See Page 17 Table 4 to select the allowable tailpipe lengths per flow unit Table 4 Allowable Tailpipe Lengths SECTION 6 RADIANT TUBE AND TAILPIPE Burner Model B 2 B 4 B 6 B 8 B 9 B 10 B 12 B 12A Radiant Tube Length average distance between burners Minimum ft 10 12 5 20 20 20 30 35 Recommended ft 15 20 25 30 30 40 50 Maximum ft 20 25 35 45 50 60 70 Tailpipe length per flow unit Minimum ft 1 2 1 2 1 2 1 2 1 2 1 2 1 2 Recommended ft 1 5 1 5 1 5 1 5 1 5 1 5 1 5 Maximum ft 2 5 2 5 2 5 2 5 2 5 2 5 2 5 Maximum ft for EP 100 only 1 7 1 7 1 7 1 7 1 7 1 7 1 7 tailpipe lengths only be used if radiant tube length is recommended or greater 17 CRV SERIES DESIGN MANUAL EXAMPLE 3 B 10 Radiant Tube vs Tailpipe Length For a B 10 burner system of 200 flow units and an average of 40 radiant tube length per burner See Page 17 Table 4 for the tailpipe lengths per flow unit that can be used and the corresponding operating characteristic From Table 4 we can use between 1 2 per flow unit and 2 5 per flow unit when the average radiant length per B 10 burner is 40 By multiplying the number of flow units in the system 200 flow units by the mini mum tailpipe length from the chart 1 2 per flow unit we see that we will need a minimum of 240 of tailpipe for this sy
42. ns must be posted to specify the maximum permissible stacking height to maintain required clearances from the heater to the com bustibles Signs must be posted adjacent to the heater thermostat In the absence of a thermo stat signs must be posted in a conspicuous loca tion Consult local Fire Marshal Fire Insurance Carrier or other authorities for approval of proposed installation when there is a possibility of exposure to combustible airborne materials or vapors SECTION 3 CLEARANCES TO COMBUSTIBLES Hang heater in accordance to the minimum sus pension requirements If the radiant tubes must pass through the building structure be sure that adequate sleeving and fire stop is installed to prevent scorching and or fire hazard AWARNING Fire Hazard Keep all flammable objects liquids and vapors the minimum required clearances to combustibles away from heater Some objects will catch fire or explode when placed close to heater Failure to follow these instructions can result in death injury or property damage CRV SERIES DESIGN MANUAL NOTE 1 Alldimensions are from the surfaces of all tubes couplings elbows tees and crosses 2 Clearances B C and D can be reduced by 50 after 25 7 5 m of tubing downstream from where the combustion chamber and the tube connect FIGURE 2 STANDARD REFLECTOR inches centimeters Model A B C D
43. nstallations with mounting heights over 60 18 m it is advisable to contact Rob erts Gordon for further information regarding the spe cific application 4 3 Selecting the Burners The number of burners and input for each must be specified in the design layout The following factors should be considered when selecting burner input Heat gain and distribution required Mounting height Flow loading restrictions Length of radiant branches Distance required between burners Desired radiation intensity In general lower burner inputs can be used for lower mounting heights and where lower heat gains are required Higher burner inputs are used primarily with higher mounting heights and where high heat gain is required The number of burners required can be calculated by dividing the input rating of the selected sizes into the 10 calculated CRV Series system required installed capacity 4 4 Radiant Distribution Radiant heat distribution at occupant level must be considered in the burner and design selection process Distribution of heat between radiant branches at floor level is more critical at the perimeter of buildings This is where the heat loss is highest Therefore it may be possible to combine different applications of distribu tion within the same building The following figures show three different applications of rules to determine distribution 4 4 1 Radiant Distribution Average Coverage T
44. nt tube lengths are variable in a single branch the average length shall be used to determine the total radiant tube length Tailpipe will begin after the last radiant tube following the last burner in the branch CRV Series is most effective when there are at least 3 burners in the radiant branch To assist with the selection of burners and system designs the following figures show system layouts that have been used extensively with CRV Series since 1962 Designing systems using these layouts will mean altering the dimensions to suit the individual building Generally shared tailpipe reduces the available sys tem vacuum See Page 14 Section 5 3 for shared tailpipe design rules LEGEND CORAYVAC Burner Pump Damper Radiant Tube Tailpipe 6 Tailpipe FIGURE 18 Example System Layout Option 1 20 6 20 k EEE 20 6 m lt gt l l L 10 Gm 7 1 Example System Layout Option 1 Six B10 burners at minimum radiant tube length and 2 5 ft flow unit tailpipe the recommended pump for this system is an EP 200 Series pump This system provides maximum radiant intensity on the left and right and adds supplemental radiant effects through the center creating very even radiant effects over the coverage area Layout to provide high system efficiency condensed radiant output and good uniformity of distribution Adjust the lengths as necessary for dif
45. stem Likewise by multiplying the number of mum tailpipe length from the chart 2 5 per flow unit we see that maximum system tailpipe length is 500 Tailpipe length range for a B 10 burner system with 200 flow units and an average radiant tube length of 40 is 240 500 The length of the tailpipe will determine whether the system is condensing or non condensing Given a certain radiant tube length and tailpipe length using Table 5 flow units in the system 200 flow units by the maxi the operating characteristic can be determined Table 5 Operating Characteristics Condensing or Non Condensing Tailpipe Length per Flow Unit Minimum Recommended 1 7 ft flow unit Maximum Radiant Tube Length average distance between burners Minimum N A NC Borderline Recommended NC Borderline C Maximum Borderline C C N A Not Allowed Condensing C Condensing 6 5 Tailpipe Design Method Given the overall length of tailpipe for the system the following section provides the method for ensuring the design will function correctly Total tailpipe includes 1 elbow 507 6 5 1 Rule of Thumb Unshared Calculations Total tailpipe 10 Optimum unshared Number of branches tailpipe per branch Select a pump discharge location and plan the route of the tailpipe For example system layouts See Page 27 Figure 18 through Page 25 Figure 26 for different pump and system efficiency requirements
46. the lowest level of intensity per length of radi ant tube and consequently the largest span between burners The radiant intensity will be reduced slightly for the last 5 10 2 3 m of radiant tube before the next burner The length of radiant tube required varies according to the burner input Consideration has been given to the use of a standard 10 3 m length of tube or lengths that can be cut from same without waste See Page 12 Table 1 When positioning radiant tube to give the required radiant distribution it is important to consider Clearances to combustible materials Lighting equipment and other suspended objects 6 2 Tailpipe Tailpipe provides a low level of radiant intensity per length The length of tailpipe for systems can be varied according to the flow units in the system and the designed radiant length Longer lengths of tailpipe will attain higher operating efficiencies and therefore con densation will occur SECTION 6 RADIANT TUBE AND TAILPIPE Page 16 Figure 16 relates the effect on system ther mal efficiency of variations in radiant and tailpipe lengths The chart was created based on test data obtained in accordance with methodology developed by the National Bureau of Standards NBSIR 80 2110 and recommendations on flue loss calculation con tained in ANSI Z83 20 CSA 2 34 latest edition Actual installation variables gas BTU content air tem perature and operation cycle etc may effect efficien
47. tronic 24 Vac thermostats and mechanical ther mostats with heat anticipator can be used The sys tem control offers a 24 Vac power supply to power electronic thermostats Roberts Gordon offers a selection of low voltage thermostats approved for use with the system control A System Control operated system has two minutes post purge pump operation to completely exhaust products of combustion from the system A system control provides indication of power to the pump and zones and indicates the status of the pressure switch with lights The System Control is ETL listed in accordance with UL873 Standard for Temperature Indicating and Regulating Equipment 8 2 ROBERTS GORDON ULTRAVAC The ROBERTS GORDON ULTRAVAC is a micro processor based control package designed for modu lating control of CRV Series heaters based on outdoor temperatures The controls offer full modulation between 60 and 100 of system maximum rated input This controller is capable of giving control outputs to one pump and three heating zones The controller also features inputs which are used for indoor and out door signal condition monitoring System status and settings are viewed and altered from a PC not supplied running ROBERTS GOR DON ULTRAVAC Software ROBERTS GORDON ULTRAVAC Software requires a PC not supplied running Windows 95 or higher with a Pentium class processor and at least 64k of RAM Special design requirements apply for
48. vice Manual P N 127102NA for ducting installation details 9 3 2 Pressurized Systems 6 diameter duct must not exceed 120 36 m total per system 4 diameter duct must not exceed 120 36 m per radiant branch See the CRV Series Installation Operation and Service Manual P N 127102NA for ducting installation details FIGURE 27 Air Supply System Capacity by Duct Length and Diameter NOTE For capacity requirements larger than shown use 8 duct 140 120 2 100 A 7 80 5 t 60 e 40 20 4 0 0 50 100 150 200 250 Straight Duct Length feet 9 3 3 Pipe sizing To size each section of pipe proceed as follows Calculate the required flow units at each outlet of the supply system Measure the longest run of pipe from the blower to the most remote outlet Use only this distance in Figure 27 or the next longer distance if the exact distance is not shown This is to provide assurance that the pressure drop to the most remote outlet will not exceed 0 25 w c when all outlets are supplied See Figure 27 find the intersection point on the graph for the appropriate duct length and number of flow units The duct size above this intersection point indicates what size duct work should be used Proceed in a similar manner for each outlet and each section of duct For each section of duct determine the total flow unit capacity sup plied by th
49. with BACnet 8 5 Pressure Switch A pressure switch is also required on the inlet duct of a non pressurized air supply 8 3 SPST Transformer Relay P N 90417600K The transformer relay can be used to control an EP 100 or EP 201 pump CORAYVAC system The single pole relay can only be used to control one zone of burners The electrical circuit is a 120 V AC 20 A supply The transformer 24 V AC output for the ther mostat is rated at 40 V A Thermostats used with the transformer must not exceed this power requirement A transformer relay operated system will not give any post purge pump operation to completely exhaust products of combustion from the system or provide indication of operating conditions The transformer relay wiring diagram is shown in the CORAYVAC Installation Operation and Service Manual P N 127102NA 8 4 DPST Transformer Relay P N 90436300 The transformer relay can be used to control an EP 100 or EP 201 pump CORAYVAC system The double pole relay can only be used to control two zones of burners The electrical circuit is a 120 V AC 20A sup ply The transformer 24 V AC output for the thermostat is rated at 40 VA Thermostats used with the trans former must not exceed this power requirement A transformer relay operated system will not give any post purge pump operation to completely exhaust products of combustion from the system or provide 27 CRV SERIES DESIGN MANUAL SECTION 9 AIR SUPPLY SYSTEM
50. xample System Layout Option 4 Nine B10 burners at recommended radiant tube length and 1 58 flow unit tailpipe the pump for this system is an EP 300 Series Pump All shared tailpipe is 6 diameter Layout will exhibit nominal system efficiency Adjust the lengths as necessary for different input systems and to increase the efficiency levels DEC Qc rS 70 21 m 1 7 5 Example System Layout Option 5 Six B10 burners at minimum radiant tube length and 1 5 flow unit tailpipe the pump for this system is an EP 200 Series pump 23 CRV SERIES DESIGN MANUAL Layout to provide minimum system efficiency Adjust the lengths as necessary for different input systems and to increase the efficiency levels This system is generally accompanied by an addi tional system as shown so that the radiant output of the additional system supplements the lack of radiant intensity from the tailpipe of the first system This lay out method is used in high heatloss and perimeter heating applications FIGURE 23 Example System Layout Option 6 10 3 m 1 100 30 lt 1 10 3 m 7 6 Example System Layout Option 6 Six B10 burners at minimum radiant tube length and 2 3 unit tailpipe the pump for this system is an
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