ENVO WH-AZ02-199-NGI vs LOCHINVAR TK-510CX3 1**: which uses less energy?
At the high draw pattern the ENVO WH-AZ02-199-NGI and the LOCHINVAR TK-510CX3 1** use the same energy, 209 therms a year each, on the same federal test. Both are filed as a gas tankless unit, so the comparison holds; what separates them is below. Enter your ZIP to price either one on your own rate.
Side by side
Compared within one class only: models filed as a gas tankless unit at the high draw pattern.
| Figure | ENVO WH-AZ02-199-NGI | LOCHINVAR TK-510CX3 1** |
|---|---|---|
| UEF (Uniform Energy Factor) | 0.81 | 0.81 |
| Energy use per year (therms) | 209 | 209 |
| Max flow (GPM) | 4.9 | 5 |
| Installed cost range | $1,698–$2,632 | $1,698–$2,632 |
| ENERGY STAR certified | not matched | not matched |
What it costs to run
Reliability
Not published: Reliability, failure rates and each model’s actual warranty term.
The registries these figures come from certify energy performance under a federal test; none of them records how long a unit lasts or how often it fails, so this page does not rank the two on reliability.
What is here instead:
- The filed efficiency, capacity and tank size of both models, side by side below.
- The actual warranty term is printed in each model’s documentation, not in any registry.
Which should you pick?
- Pick the ENVO WH-AZ02-199-NGI if its price or availability suits you — on energy the two are level.
- Pick the LOCHINVAR TK-510CX3 1** if you run more fixtures at once: it lists 5 GPM against 4.9.
- Neither if you need more than 5 GPM at the same time — neither unit lists more. Check how to size a tankless unit by GPM.
Each model on its own
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ENVO WH-AZ02-199-NGI
Its filed figures, class position and running cost on your ZIP.
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LOCHINVAR TK-510CX3 1**
Its filed figures, class position and running cost on your ZIP.