Rinnai RX180I REU-NB2934FF-US vs Takagi T-H3-OS-N 1
The Rinnai RX180I REU-NB2934FF-US is the more efficient unit: UEF 0.98 versus 0.95 — about 3% less energy for the same hot water. At national average rates that works out to about $251/year for the Rinnai RX180I REU-NB2934FF-US against $258/year for the Takagi T-H3-OS-N 1 — a $7 annual difference. The Takagi T-H3-OS-N 1 sustains the higher flow (5.8 GPM vs 5.3 GPM under the DOE test).
| Rinnai RX180I REU-NB2934FF-US | Takagi T-H3-OS-N 1 | |
|---|---|---|
| Uniform Energy Factor (UEF) | 0.98 | 0.95 |
| Fuel | Natural Gas, Propane | Natural Gas |
| Max flow rate | 5.3 GPM | 5.8 GPM |
| Draw pattern | High | High |
| Annual gas use (natural gas) | 173 therms/yr | 178 therms/yr |
| Gas input rate | 180 kBTU/h | 199 kBTU/h |
| Max current draw | 4 A | 5 A |
| Vent type | Power Direct Vent | Power Vent |
| Recovery efficiency | 98 % | — |
| Smart / connected capable | No | No |
| Minimum activation flow | 0.1 GPM | 1 GPM |
| Annual propane use | 189.07 gal/yr | 194.53 gal/yr |
| Vent size | 2 | 3 |
| Height | 25.8 in | 22 in |
| Diameter | 11.4 in | — |
| Width | 18.5 in | 18 in |
| Depth | 11.4 in | 11 in |
| ENERGY STAR certified | Yes | Yes |
Frequently asked questions
Which costs less to run, the Rinnai RX180I REU-NB2934FF-US or the Takagi T-H3-OS-N 1?
The Rinnai RX180I REU-NB2934FF-US: about $251/year versus $258/year for the Takagi T-H3-OS-N 1 at national average rates — a $7 annual difference.
Are the Rinnai RX180I REU-NB2934FF-US and Takagi T-H3-OS-N 1 both ENERGY STAR certified?
Yes — every water heater in this database is drawn from the U.S. EPA ENERGY STAR certified water heater datasets.