Hot Water System Design Manual Plumbing schematics for single and multiple Rinnai tankless water heaters in use with domestic systems, recirculation, and storage tanks.
Table of Contents Certifications................................................................ 3, 4 Non-condensing Water Heaters Rinnai Accessories ......................................................... 4 Drawing MSB Kits for Connecting Multiple Water Heaters ........ 5 WH1 1 Basic Piping................................... 29 Model Applicability .......................................................... 6 WH2 2 Basic Piping................................... 30 Water Quality and Scale .....
Certifications Indoor Water Heaters Trade Name CSA Listing V53i, RV53i........... REU-VB2020FFU-US-(N, P) R50LSi .................. REU-VA2019FFUD-US-(N, P) * R75LSi, RL75i ...... REU-VB2528FFUD-US-(N, P) * R75LSi .................. REU-VA2528FFUD(A)-UC-(N, P) * R75LSi .................. REU-VA2528FFUD(A)-US-(N, P) * R75LSi .................. REU-VA2528FFUD-US-(N, P) * R94LSi, RL94i ...... REU-VB2735FFUD-US-(N, P) * R94LSi .................. REU-VA2535FFUD-UC-(N, P)* R94LSi ..................
Certifications R98LSiASME R98LSeASME R R98iASME C98iASME R98eASME C98eASME These models are built in accordance with the requirements of the ASME Boiler and Pressure Vessel Code and received the Certificate of Authorization from the National Board. The heat exchanger has the NB and the HLW stamps. Rinnai Accessories Multiple Unit Connections (refer to model applicability) MSB Controller: The MSB kits can electronically connect up to 25 water heaters and allows them to function as one hot water source.
MSB Kits for Connecting Multiple Water Heaters Water Heater PC board Each bank is controlled by an MSB-M control board. These boards are connected to each other with MSB-C2 cables. One MSB-M is the controlling or master MSB-M for the entire system.
Model Applicability (Accessories) Outdoor Model Pipe Covers Electronic Connection Remote Controllers PC-20-W (white) [6] [1] Recess Boxes V53e, RV53e RGB-20-U PCD01-SM2 (silver) R63LSe2 R75LSe, RL75e, R94LSe, RL94e [2] RGB-25-U or RGB-25U-MSAL (with moisture seal flange) PCD03-SM2 (silver) RGB-32 PC-32-W (white) PC-32-G (gray) [2] RGB-CTWH PCD07 [2] Venting Type Integrated Condensate Collector R98LSe, R98LSeASME RC80HPe, RC80e, RC98HPe, RC98e [2] EZConnect™ [5], MSA-2, MSB Indoor Mo
Water Quality and Scale The rate of scaling increases with temperature and usage because calcium carbonate and other scaling compounds lose solubility (fall out of solution) at higher temperatures. For example, for every 20°F over 140°F, the rate of scale increases by a factor of 2 (See figure below). Reference target water quality levels below and treat the water if these levels are exceeded.
Pump Sizing for Circulation 1. Use the chart below or one appropriate for your conditions to determine the heat loss in the length of the hot water supply and return piping. For example, 100 ft of 1-1/2 in bare copper tubing results in a heat loss of 5300 Btu/h. Approximate Heat Loss from Piping at 140 ºF Inlet, 70 ºF Ambient * Nominal Size, in. Bare Copper Tubing, Btu/h-ft 1/2 in. Glass Fiber Insulated Copper Tubing, Btu/h-ft 3/4 30 17.7 1 38 20.3 1-1/4 45 23.4 1-1/2 53 25.4 2 66 29.
Tank Water Heaters in a Circulation Loop The following applies when using a tank water heater (gas or electric) to provide heat for a circulation loop. Drawing WH1-RGE is an example. The heat output of the tank must be equal to or greater than the calculated circulation loop heat loss. (Reference page 7, Step 1 on calculating heat loss).
Vent Termination Clearances TERMINATION Clearance in Ref.
Vent Termination Clearances Ref Description Canadian Installations US Installations A Clearance above grade, veranda, porch, deck, or balcony 12 inches (30 cm) 12 inches (30 cm) B Clearance to window or door that may be opened 36 inches (91 cm) 12 inches (30 cm) C Clearance to permanently closed window * * D Vertical clearance to ventilated soffit, located above the terminal within a horizontal distance of 2 feet (61 cm) from the center line of the terminal * * E Clearance to unventila
Additional Clearances These clearances are to supplement the clearances specified in ANSI Z223.1 which are currently in the FFU (indoor) and W (outdoor) manuals. They apply to all water heater models. Local codes supersede these recommendations. General Recommendations • Avoid termination locations near a dryer vent. (See TB-46 for more information.) • Avoid termination locations near commercial cooking exhaust. W (Outdoor) Models 36" 12" (0.
Additional Clearances Termination of FFU (Indoor) Models 60" (1.52 m) vertically between Rinnai terminals (0.91 m) to ventilated 36" or unventilated soffit or eve vent; or to a deck or porch 12" (0.30 m ) to an inside corner 12" (0.61 m) to wall or parapet (0.30 m) between Rinnai terminals at same level 24" INSIDE CORNER (1.52 m) between Rinnai terminals at different levels 60" 12" 13 (0.
Pump Sizing for Storage Tank Application The following applies when using Rinnai tankless water heaters to recover a storage tank. Drawing WH1-BC is an example. Rinnai Tankless water heaters have a pressure loss which must be considered in the system design. Reference the pressure loss curve for the Rinnai model being used to determine the pump size for the desired recovery rate. For recommended pump sizes use the table below.
Pressure Loss Curves - Non Condensing Models R94LSi/e RL94i/e R63LSe R75LSi/e RL75i/e R50LSi 45 R98LSi/e R98LSi/eASME 100 80 30 70 25 60 50 20 40 15 30 10 Pressure Loss (ft head) 90 35 20 5 10 0 0 0 1 2 3 4 5 6 7 8 9 10 11 Water Flow (gpm) 45 40 90 35 80 30 70 60 25 50 20 40 V53e RV53e 15 30 10 20 V53i RV53i 5 Pressure Loss (ft head) 100 Pressure Loss (psi) Pressure Loss (psi) 40 10 0 0 0 1 2 3 4 5 6 Water Flow (gpm) 15 R-TRWH-E-02 Rev D
Pressure Loss Curves - Condensing Models RC98HPi/e RC98i/e Pressure Loss (ft head) Pressure Loss (psi) ) RC80HPi/e RC80i/e Water Flow (gpm) 16 R-TRWH-E-02 Rev D
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R-TRWH-E-02 Rev D Connect pump outlet hose (H1) to the cold water line at service valve (V2). Connect drain hose (H3) to service valve (V1). Pour 4 gallons of undiluted virgin, food grade, white vinegar into pail. Place the drain hose (H3) and the hose (H2) to the pump inlet into the cleaning solution. Open both service valves (V1 and V2) on the hot water and cold water lines.
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R-TRWH-E-02 Rev D © 2011 Rinnai America Corporation 8/2011
