Sooner or later, every commercial building manager must consider an upgrade to their water heating system—whether because their current system has taken on wear and tear, the facility itself is expanding, or peak hot water needs have changed.
Among the many strategic decisions to make is the decision to choose tankless water heaters, conventional tank units, or in some cases, opt for both.
Thanks to advances in water heating technology, tankless heaters are increasingly viable in commercial spaces. At the same time, conventional tank units are as efficient and reliable as ever and may prove more than adequate for meeting a facility’s goals.
When assessing whether it makes sense to “go tankless” or stick with something conventional, there are a number of factors to consider.
Go with the Flow
One place to start is by ensuring the building can actually accommodate tankless units. The answer is almost always going to be yes, though there may be a few factors related to the age and plumbing infrastructure of the building that make tankless units less advisable.
One consideration is the building’s water flow. Flow rate doesn’t matter for conventional tank heaters, but it can have a significant impact on how tankless units perform.
In fact, most tankless heaters require a minimum flow rate in order to activate, and if they don’t meet this threshold, the unit simply won’t work. When multiple fixtures are used at once, the tankless unit must meet the combined flow rate demand, or else users will experience inconsistent temperatures or reduced water pressure.
This matters most in older commercial buildings that have outdated piping. For example, any kind of galvanized piping is going to be naturally flow-restrictive, which may make it impossible to run tankless units efficiently (at least not without a large-scale re-piping job).
While uncommon, some buildings may also have a hodgepodge network of different piping materials, such as cross-connectors that cause hot water to bleed into cold. Here again, getting tankless units to work may require significant updates to the building’s existing plumbing systems.
Handling Peak Demand
Another question for facility managers to ask: Are tankless heaters reliable enough to meet the building’s hot water needs?
This concern may loom especially large in facilities such as restaurants, hotels, and fitness centers—spaces where there may be especially high demands for hot water, and where any inconsistency in hot water availability could result in health code violations or other penalties.
Today’s tankless systems are robust enough to meet even the highest levels of hot water demand, which means they can work well in these and other types of commercial spaces. Having said that, there are a few technical considerations to bear in mind.
The first is that a water heating system needs to accommodate all levels of water demand, from zero to the absolute peak. That will require several tankless units. For example, in the standard commercial kitchen, it’s typical to have four to six tankless units to ensure consistent hot water delivery. The goal is to create redundancy, ensuring that if one unit is already working at its maximum capacity (or experiences any kind of failure), another unit can pick up the slack.
One potential problem is that, by designing a system for peak demand, there may be many parts of the day where the system is effectively overkill. This is where it might make sense to combine some tankless units with a storage tank, which can help to decouple the demand cycle from water storage.
Considering Costs
Facility teams will understandably have questions about the cost and long-term value of going tankless.
The cost of the unit itself is not a big factor, but installation costs may be more notable. Most buildings will need new venting to accommodate a tankless unit, though thankfully, the materials can be very inexpensive. A bigger issue is ensuring a gas line large enough to meet heating demand. Commercial spaces may already have a sizable gas line in place, but if not, this can be a significant expense.
In terms of system longevity, it’s standard for tankless units to have roughly eight-year warranties, though most units last for 12 to 15 years without major issues. This assumes regular upkeep, which can be more significant than with conventional tank heaters. More specifically, tankless units must be flushed and descaled regularly.
A final question: Will switching from a conventional tanked heater to a tankless help facilities uncover significant energy savings, potentially lowering monthly utility costs? If the tank unit that’s being replaced is old and out-of-date, the answer may be yes. However, modern storage tanks have become much more energy efficient than their predecessors, which means the energy savings between a brand-new tankless unit and a brand-new tanked unit are often very similar.
No One-Size-Fits-All Solution
For most commercial buildings, tankless water heating systems are a viable option. However, in determining whether they make more sense than conventional units (or even a hybrid approach), facility teams must assess the specific needs and goals of their space.
