American ATHR-180M 1 (MTHR-180M 1) vs Friedrich FDTGH-S10I
The Friedrich FDTGH-S10I is the more efficient unit: UEF 0.96 versus 0.95 — about 1% less energy for the same hot water. At national average rates that works out to about $255/year for the Friedrich FDTGH-S10I against $258/year for the American ATHR-180M 1 (MTHR-180M 1) — a $3 annual difference. The American ATHR-180M 1 (MTHR-180M 1) sustains the higher flow (5.3 GPM vs 5.2 GPM under the DOE test).
| American ATHR-180M 1 (MTHR-180M 1) | Friedrich FDTGH-S10I | |
|---|---|---|
| Uniform Energy Factor (UEF) | 0.95 | 0.96 |
| Fuel | Natural Gas, Propane | Natural Gas, Propane |
| Max flow rate | 5.3 GPM | 5.2 GPM |
| Draw pattern | High | High |
| Annual gas use (natural gas) | 178 therms/yr | 176 therms/yr |
| Gas input rate | 180 kBTU/h | 180 kBTU/h |
| Max current draw | 5 A | 2 A |
| Vent type | Power Vent, Power Direct Vent | Direct Vent |
| Recovery efficiency | 97 % | 98 % |
| Smart / connected capable | No | No |
| Minimum activation flow | 1 GPM | 0.4 GPM |
| Annual propane use | 194.53 gal/yr | 192.35 gal/yr |
| Vent size | 3 / 2 | 2 |
| Width | 17 in | 18.1 in |
| Depth | 16 in | 13.6 in |
| ENERGY STAR certified | Yes | Yes |
Frequently asked questions
Which costs less to run, the American ATHR-180M 1 (MTHR-180M 1) or the Friedrich FDTGH-S10I?
The Friedrich FDTGH-S10I: about $255/year versus $258/year for the American ATHR-180M 1 (MTHR-180M 1) at national average rates — a $3 annual difference.
Are the American ATHR-180M 1 (MTHR-180M 1) and Friedrich FDTGH-S10I both ENERGY STAR certified?
Yes — every water heater in this database is drawn from the U.S. EPA ENERGY STAR certified water heater datasets.