How does HWAT technology drive sustainability in commercial buildings and safety and convenience for occupants
The following is a Q&A with Bob Silva. Bob is a marketing manager for nVent Thermal Management with more than 20 years of experience in operations, sales, product management and marketing for electric heat trace products.
For those who are not familiar with the term, what is HWAT?
Hot Water Temperature Maintenance—HWAT—systems are a technology solution used to create a single-direction hot water delivery system that can drive efficiency, safety and water savings for customers. HWAT systems are deployed in multi-family, condominium and residential housing, as well as in hotels, offices, hospitals, schools and other commercial and institutional buildings.
An HWAT system consists of sensors at the site of hot water heaters, an electronic controller to control water temperature, and insulation and self-regulating heating cables on water pipes to maintain hot water temperature to points of use. This system can deliver instant hot water as soon as building occupants turn on the tap, all but eliminating wasted water used while people wait for hot water to heat up.
How do HWAT systems bring sustainability to hot water distribution?
Traditional hot water systems recirculate water through a circulation loop and then unused water is returned to the water heater and reheated to keep it hot enough to meet the needs of building occupants. Recirculation systems require that water heater temperatures are at least five degrees above the desired temperature coming out of the faucet since water loses heat as it recirculates through pipes. This overheating process wastes energy. HWAT systems keep water temperature consistent throughout the system without recirculation. Eliminating recirculation loops also saves materials in construction.
A key component of the HWAT system is the HWAT controller. In addition to providing flexible temperature control, the controllers provide energy savings by intelligently using only the power that is necessary to maintain temperatures. Additionally, self-regulating heating cables are inherently efficient, because they do not carry a current when cable temperatures reach a certain point—this means that cables cannot run and consume energy when they are not necessary.
What additional benefits do HWAT systems bring building occupants?
In addition to energy savings, HWAT systems make submetering easier since the system is one-way. This makes it easier for individuals to track and address their individual water consumption. Additionally, HWAT temperature control systems can effectively maintain the temperatures required for your building services Legionella risk management program. For additional information for the proper design, installation, operation, maintenance and management of your building water systems to minimize the risk of Legionella Disease see ASHRAE 188-2018 and CIBSE TM13: 2013.
Alongside the sustainability, efficiency and safety reasons to implement HWAT, these systems are also simply very convenient. Who wouldn’t want instant hot water? Not having to sit around and wait for your sink or shower to heat up not only saves water but also creates a more positive day-to-day experience for building occupants.
What makes nVent HWAT systems stand out compared to alternatives?
We are a leader in self-regulating heating technology. We patented and produced the first commercially available self-regulating heat-trace cable, and we have a legacy of expertise in the field. Additionally, our monitoring and control technology is utilized everywhere from clean fuel production to ice melting. Our experience with the underlying technologies that make up these systems is crucial to being able to advise our customers on the best solutions for their specific needs. As a result of our expertise and our broad portfolio, our solutions are easy to specify, safe and extremely reliable. Our heating cables, components and controls are designed and certified as a system to optimize installation and performance.