In my last post I debated the merits of tankless vs a high efficiency tank style water heater. Well, after talking it through with the client we decided to specify the AO Smith Vertex 100 for a new home we’re building to the highest 5 Star Austin Energy Green Building standards. This is a pretty amazing machine wrapped in an old-school body. It’s a typical looking 50 gallon tank but achieves 96% thermal efficiency.
It has a 100k BTU gas input (most tank units are 40k) so it’s about 50% as much gas input as the 200k BTU Rinnai tankless I usually install. They claim it can run 4 gallons per minute of hot water indefinitely. That makes sense because the tankless units can usually handle 8 gallons per minute endlessly. But, with 50 gallons of standing hot it would be really hard to run out of hot water. As a side benefit with a tank style heater you’ll still have hot water even if the power goes out. With the tankless unit at my house when power goes out I don’t have hot water as it needs electricity to spark the gas burner and run the electronics. This unit won’t fire if power is off but it will have 50 gallons standing at the ready. In a bigger emergency like a tornado or earthquake where city water is interrupted this could also be beneficial to have 50 gallons of water to drink if the tank was drained.
Lastly, compared to the cost of two tankless units this Vertex 100 is about 2/3rds the cost. It’s a great choice for my clients family of 4. I’ll be sure to review it post-install.
If you decide this is the water heater for you, help support my blog by buying your AO Smith Vertex 100 from Amazon. -Matt Risinger