A non-condensing tankless water heater is considered more efficient compared to the conventional tank-equipped type, but a condensing model is the most efficient of all, such as the Rinnai RU98EN. It is one of the most powerful water heaters from Rinnai categorized under Ultra series, featuring 0.95 energy factor, 9.8 GPM, and an easy-to-use temperature controller.
Main Features and Benefits
1. Condensing Water Heater – As mentioned earlier, the Rinnai RU98EN is a condensing tankless water heater, which is considered the most efficient model compared to others currently available. In a combustion process, fuel is burned thus it produces hot gases. In this case, hot gases are used for heating the water. With a non-condensing model, some of the hot gases are simply pushed through the vents to the outside, therefore wasted.
A condensing tankless water heater, such as the RU98EN, transfers the exhaust gases to heat the incoming water. In other words, energy optimization is much better.
2. Two Heat Exchangers – In order to operate as a condensing water heater, the Rinnai RU98EN uses two heat exchangers; one is made of steel, while another is made of copper. The stainless heat exchanger is used for recapturing the heat produced by the combustion process. The copper-made one uses pre-heated water to deliver optimum heating process above the gas burner. Cold water is already pre-heated before it flows through the primary burner, allowing for optimum heating process. According to the manufacturer, the RU98EN reaches energy factor of 0.95 for either natural or propane gas. [Read more...]
It features a compact design measuring at 15-inch x 24-inch x 4-inch and weighing only around 20 pounds, but this tankless water heater brings separate gas and water controls as well as a digital display for temperature on the front. With such controls and indicator, you can manually adjust water flow and the intended temperature precisely. The appliance also has 0.5 inch NPT inlet and outlet as well as gas connections. The Eccotemp FVI-12-NG starts by an electronic ignition that requires a minimum of 40 PSI.
The V65EN uses a direct electric ignition device that requires a minimum flow rate of 0.4 GPM to light the burner. The maximum pre-set temperature range starts from 98 to 120 degree F, but you can use the provided temperature control to widen the range from to a maximum of 140 degree F.
The heating element will transfer heat directly to the water and it shuts down instantly after you are done using it. The cooling process is as well very quick, meaning there is only minimal overshoot to prevent inefficient use of energy.
In terms of energy efficiency, this appliance is smartly equipped with all-copper heat exchanger. Copper is one of few materials with high thermal conductivity, meaning it has an excellent ability to conduct heat. When used for heat exchanger, copper is better than other common metals such as stainless steel and aluminum. In fact, copper has a higher thermal conductivity compared with all other metals except silver. Since heat can pass through copper very quickly, less energy is required to produce hot water.