warm thoughts


Written on: May 9, 2022


As tankless water heaters have become common in homes across the country, the idea of using them in commercial buildings still gives pause to some engineers and architects.

But as the design community learns more about tankless technology designed for commercial applications — and how the technology has evolved from its residential roots — that hesitation is giving way to enthusiasm, manufacturers say.

“Now the technology and the products have evolved so much, more and more installers are saying, ‘Yeah, why wouldn’t I choose a tankless water heater, because they have much better efficiency?’” says Jon Nelson, commercial business manager for the Northeast region at tankless manufacturer Rinnai. “You’re talking something that’s 97 percent thermally efficient. That’s amazing.”

With its ability to provide significant energy cost savings for facilities, as well as redundancy in the event a unit goes down, tankless water heating is gaining attention for a variety of building types. Make sure you’re aware of these seven factors that set commercial tankless water heating apart — and likely make it a viable option for your next project.

1. Commercial tankless units provide higher output temperatures.

Commercial-grade tankless water heaters are typically set to a 140-degree-Fahrenheit set point temperature out of the box, but they can be set to a max temperature as high as 185 degrees (compared with 140 degrees for a typical residential unit). “That 185 degrees is going to be hugely beneficial in healthcare applications,” Nelson says, “as well as restaurants that need it for their local operating code.”

2. Tankless rack systems easily combine multiple units.

The trend toward using banks of multiple tankless water heaters for commercial applications is quickly picking up steam, says Rich Fox, Northeast territory sales manager for tankless manufacturer Navien. “It provides redundancy and installation advantages,” he says. The manufacturer’s Ready-Link manifold systems allow contractors to mount multiple units on a wall or rack in multiple configurations, using a commercial application guide for example setups.

For its Sensei commercial units, Rinnai also offers about 15 predesigned rack systems in various configurations where the tankless water heaters are mounted, pre-piped, and live fire tested at the factory to save installation time on the jobsite. The tankless racks can also be common vented, where each of the tankless units shares a 6-inch flue gas vent and air intake vent, reducing the number of penetrations in the wall of the property.

Intellihot’s larger commercial tankless water heaters are an alternative option for large hot-water loads, combining multiple modules within a single high-capacity unit to offer redundancy with capacity up to 3 million Btu per hour.

3. Commercial tankless water heaters are designed to last longer.

While tankless water heaters are known for their long lifespan compared with tank-style units, manufacturers made their commercial models even tougher. Commercial units generally use stainless-steel heat exchangers with longer durability, and rack systems are engineered for commercial environments so building operators can expect longer life for their equipment.

4. You can combine tankless and tank-style water heating.

Although tankless water heating is growing in popularity, commercial tank-style units are still predominant in the industry. Products such as Rinnai’s Demand Duo can be used to upgrade those tanks and provide greater first-hour hot-water delivery. Rather than relying on a heating coil inside the tank, these units create hot water in tankless units strapped to the tank, providing the efficiency of tankless water heating with the storage capacity of an additional tank.

5. Tankless technology runs on propane and natural gas.

By consuming clean propane on site with extremely high efficiency, tankless water heating can reduce a building’s carbon footprint compared with electric options that use grid electricity from less-efficient coal- or gas-fueled power plants. Buildings without access to natural gas lines can run their tankless equipment with propane — and units can be adapted to run on natural gas if the building converts later.

6. Manufacturers can help design your tankless system.

Tankless water heater manufacturers offer a variety of design assistance in the form of tools you can use on your own or engineering assistance customized to your project. Navien’s NaviSizer app, for example, allows designers to develop system specs based on the details of their commercial project. Rinnai’s plumbing engineer team can take the details of the project and recommend good/better/best options based on the building’s hot-water demand.

7. Tankless product is available.

Nearly every product category has been hit with supply chain issues, and tank-style water heaters have seen repeated price increases in the past two years. That’s why the most exciting part of the conversation Nelson has with potential customers is the ready availability of tankless product. If there’s not already product in stock, Rinnai can get units to a project in 17 business days. For projects ready to move forward now, propane tankless water heating is an option that can provide the energy efficiency and redundancy building owners are seeking.