Enviroment: Local
Commercial Tankless Water Heater

Commercial Water Heating Solutions

Sometimes the difference between "open for business" and "closed for repairs" is the reliability of a water heating system.

That's why for decades, a full spectrum of commercial applications - from retrofit to new construction and light to heavy - have trusted Rinnai Tankless Water Heaters. Because the system configures to your needs and to every kind of space, every usage demand is the perfect Rinnai fit - and that makes it easy to do business.

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How a Rinnai tankless water heater works

When the need for hot water arises by turning on a shower, washing machine, dishwasher or faucet, cold water enters the Rinnai Tankless Water Heater from the inlet pipe at the bottom of the model. The PC board is then signaled to activate the flame igniter or ignition.

A combustion fan turns on to allow oxygen into the burner to ignite the flame as the gas control valve opens at a low frequency. Once an adequate flame is present the igniter stops sparking — beginning the next sequence of operation in a matter of seconds.

Water is heated as it passes through the coils of the copper heat exchanger, and exits from the hot water outlet pipe to travel through the pipes of the home or business to the water fixture where hot water is needed. Condensing models use the latent heat of exhaust to preheat incoming cold water. The colder the inlet water, the higher the efficiency and the more condensate is generated. The water is preheated as it passes through a secondary stainless steel (latent) heat exchanger, capturing any extra heat (or latent heat) before it escapes into the vent system.

The gas valve and blower automatically adjust the incoming gas and oxygen to meet the water heating demands. If the demand is small, the Rinnai Tankless Water Heater can use a smaller flame and less gas. If the demand is greater, the flame can expand across the width of the entire burner to heat more water. The tankless water heater adjusts as needed to ensure the temperature set point is maintained. A digital controller allows the user to choose the desired temperature.

As the hot water fixture shuts off, cold water stops entering the tankless water heater and the flame extinguishes. The combustion fan continues to operate at a low speed for a short period of time. This allows the exhaust of any leftover combustion gases in the system.

How condensing technology works

As illustrated in the diagram below, condensing appliances use the latent heat of exhaust to preheat incoming cold water. The colder the inlet water, the higher the efficiency and the more condensate is generated.

How modulation works

The chart below demonstrates the efficiency that a fully modulating tankless system can provide. The chart generally shows the gas usage of a traditional boiler compared to that of a Rinnai Tankless Water Heater.* Peaks represent the tankless unit meeting user demands, and valleys represent saved energy in between.

*The comparison is not based on data from a specific installation.

How a tankless rack system works

Rinnai’s Tankless Rack System (TRS) is designed to supply a packaged water heating solution as a fully-assembled system. The TRS includes preassembled water and gas connections and manifolds under the tankless water heaters that are properly sized to maintain optimum performance.

Tankless technology provides an endless supply of hot water and the Tankless Rack System provides the ability to link multiple units together, giving redundancy ensuring the business remains open 24/7/365.

All of the water heaters on the TRS can be electronically connected using the multi-system control board. When operating, multiple tankless water heaters linked together with multi-system controls are designed to supply equal amounts of hot water. They will also rotate occasionally to ensure equal usage among the entire system.

On initial water flow 1 to 3 units will start up based on the configuration of the main multi-system control board. Once the flow rate is determined, the multi- system control board will cycle additional units on or off as needed.