Sizing Guide - Rheem RTEX 8 Instructions D'installation Et Guide D'utilisation

6- SIZING GUIDE

The chart below indicates maximum temperature rise for a given flow rate
+ Temperature electronically limited setting on adjustable thermostat on front cove
MAX
ACTIVATION
FLOW FLOW
GPM
kW GPM (LPM)
(LPM)
8 .3(1.1) 5(18.9)
11 .3(1.1) 5(18.9)
13 .3(1.1) 5(18.9)
18 .3(1.1) 7(26.5)
24 .3(1.1) 7(26.5)
27 .3(1.1) 7(26.5)
36 .3(1.1) 8(30.9)
To ensure the optimal temperature output and overall performance of your tankless water heater you may
require a flow regulator. These flow regulators are installed on the outlet connection of your tankless water
heater and limit the maximum volume coming out of your unit to a specified flow rate to prevent the exit
temperature from becoming too cool. To learn more about flow regulators or find out how to purchase one for
your tankless water heater contact Manufacturer's national service department at 1-(800)-374-8806.
Steps for Choosing a Flow Regulator
1. Find your heater input in the chart on the left
2. Choose the column with the inlet water temperature closest to your geographical location
3. Take the GPM or gallons per minute you find and match it with the corresponding flow regulator on the
right
Inlet Water Temperature GPM(LPM)
40°(4°C)
8kW
1.0 (3.7)
11kW 1.0 (3.7)
13kW
1.0 (3.7)
18kW
2.0(7.6)
24kW
2.0(7.6)
27kW 2.0(7.6)
36kW
3.0(11.4)
*Selection based on inlet temperature above and outlet temperature of 105°F (41°C)
1(3.8) 1.5(5.7) 2(7.6)
GPM(LPM) GPM(LPM) GPM(LPM) GPM(LPM) GPM(LPM) GPM(LPM) GPM(LPM) GPM(LPM) GPM(LPM)
55(31) 36(20) 27(15)
77(43) 50(28) 38(21)
89(49) 59(33) 44(24)
+ 82(46) 61(34)
+ + 82(46)
+ + 92(51)
+ + +
FLOW REGULATOR – OPTIONAL
50°F(10°C) 60°F(16°C)
1.0 (3.7) 1.0 (3.7)
1.0 (3.7) 1.5 (5.7)
1.0 (3.7) 1.5 (5.7)
2.0(7.6) 2.0(7.6)
2.0(7.6) 3.0(11.4)
3.0(11.4) 4.0(15.1)
4.0(15.1) 5.0(18.9)
MAXIMUM TEMPERATURE RISE °F (C°)
3(11.4) 4(15.1) 5(18.9)
18(10) 14(8) 11(6)
25(14) 19(11) 15(8)
30(17) 22(12) 18(10)
41(23) 31(17) 25(14)
55(31) 41(23) 33(18)
61(34) 46(26) 37(21)
82(46) 61(34) 49(27)
Part
70°F(21°C)
Number
1.5 (5.7)
ECO IFR-
2.0(7.6)
1-2
2.0(7.6)
3.0(11.4)
4.0(15.1)
ECO IFR-
3-4
5.0(18.9)
5.0(18.9)
6(22.7) 7(26.5) 8(30.3)
9(5) 8(4) 7(4)
13(7) 11(6) 9(5)
15(8) 13(7) 11(6)
20(11) 18(10) 15(8)
27(15) 23(13) 20(11)
31(17) 26(14) 23(13)
41(23) 35(19) 31(17)
Maximum Flow
Connection Size
Rate GPM(LPM)
1.0 (3.7) 1/2"
Compression
1.5 (5.7) 1/2"
Compression
2.0(7.6) 1/2"
Compression
2.0(7.6) 3/4" NPT
3.0(11.4) 3/4" NPT
4.0(15.1) 3/4" NPT
4.0(15.1) 3/4" NPT
7