Rinnai RH180, Installation Fundamentals

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RH180 Sizing
Water Heating
Options
Max input (Btuh
/ Kwh)
Tank Capacity
(gal.)
Time of available
hot water (min.)
Time of available
hot water (min.)
Recovery time
(min.)
Showers In use
at one time
70⁰ temp rise 70⁰ temp rise 70⁰ temp rise
Electric Tank 4.5 Kw 40 21 10 88
Gas Tank
34,000 Btu 40 18 8 36
40,000 Btu 50 26 11 40
75,000 Btu 75 50 19 32
Rinnai RH180
Hybrid
Tank -Tankless
91,300 Btu 40 Continuous 11 16
Rinnai Tankless
Up to 199,000
Btu
N/A Continuous Continuous N/A
• Data is based on a 50⁰F inlet water temperature and a 120⁰F hot water set point (70⁰F rise).
•
Shower heads assumed to be 2.5 gpm mixed flow rate with 105⁰F at the fixture.
• Available hot water time and recovery time based on industry standard calculation methods
and Rinnai lab testing. Actual results may vary based on the application.