The T-H2, Takagi's Greenest Model has an Average Efficiency of 92% with Natural Gas Est. and 95% with Propane Est. . At A ?T Of 60deg. F In Warmer Areas - Where The Winter Ground Water Is 60ºf And With The Output Set At 120deg. F - The Unit Will Provide 6.1 Gpm, Or 366Gph. In Other Areas Where The Input Temperature May Be 40deg. F Or Less, You Can Expect A Flow Rate Of About 4.6 Gpm Or 276 Gph The T-H2 Can Provide At Least Three Showers' Worth Of Water Simultaneously Along With One Appliance At Input Temperature Of 60ºf Or Greater The T-H2 Can Be Vented With PVC, Providing 0 Clearance For DV Installations. PVC Venting Can Be Used In All Applications And 3" Exhaust Venting Is Coming Soon. This State-Of-The-Art Tankless Water Heater Uses Not One, But Two Heat Exchangers To Maximize The Unit'S Energy Efficiency, Resulting In The Higher-Than-Average Efficiencies Stated Above.
From the Manufacturer
The T-H2, Takagi's greenest model, is the 2nd Generation High Efficiency Tankless unit with an average efficiency of 92% with natural gas (estimated) and 95% with propane (estimated). High efficiency, condensing model. Llow emission, low Nox. Easy-ling up to 4 units. Overheat cut-off fuse.