Hybrid Water Heaters

Hybrid Water Heater Offers Endless Learning Potential

Sept. 5, 2018
Florida school system finds answers that ensure reliable hot water supply, reduce operating costs, and provide durability.


By Rinnai America Corporation, Peachtree GA

Like any other public school system, Pinellas County Schools in Florida operate on a tight budget and answer to a lot of vested parties, including a school board, parents and taxpayers. So, it’s no surprise that they’re always looking for ways to function more efficiently and effectively, to better serve students, save money and reduce time spent on equipment upkeep.

When water heating units started failing in Countryside High School, the county began searching for a dependable, efficient and serviceable solution for the school and its students and staff. What the county needed was a hot water source that didn’t have the same fallibility and short service life as the units they currently used. Moreover, they needed a system that offered redundancy, to avoid a complete loss of hot water during the school day.

Smarter Hot Water, Quick and Easy

For years, the Pinellas County School System, located in the Tampa Bay area of Florida, relied on traditional tank-style water heaters. However, over time, those responsible for maintaining and servicing these units realized their lifespan was shorter than they had expected — typically only six to eight years, at the most.

With the heat exchanger located on the inside of the unit, acidic condensate was consuming the tanks from the inside out, eventually causing the tanks to rupture. “With such a short life span, I knew there had to be a better alternative,” said Ty Crawford, in charge of maintenance for the school system. “We’ve been running Rinnai tankless products in other schools for about 10 years now, so we trust (them).”

“I’d heard about the Demand Duo,” Crawford continued, “and I thought it sounded like it might be the ideal solution for us. So I started looking into it.” It wasn’t long afterwards that Tempaco, an Orlando-based distributor of natural gas and propane products, installed three Rinnai Demand Duo hybrid units at Countryside High School. These direct replacement solutions were a fast, straightforward upgrade from the school’s tank-style units. And the successful installation has since led to more installations at other schools throughout the Pinellas County School System.

How It All Came Together

When it came to heating water, Pinellas County Schools were concerned with increasing equipment life and cutting costs – not only for the new water heater install, but also for the long-haul on energy usage.

It was Crawford who suggested Rinnai again to Tempaco, but this time he was interested in what the Demand Duo had to offer.

“The ease of installation was the first big factor for Pinellas County,” said Tempaco’s Lewis Johnson. Rinnai’s Demand Duo Hybrid Water Heaters feature connections similar to most tanks. So customers quickly can replace a standard tank and be operational again, with a minimum of disruption.

“They also liked the combination of tank-style and tankless technology, because that meant the heat source – the heat exchanger – was located outside the tank,” said Johnson. “And given the issues with their previous units, that was a huge factor.”

Savings From Day 1

According to Crawford, installed costs on the new units were about half the cost of sticking with the same units the school had previously used.

“The up-front price difference was huge,” said Crawford, “but what has really surprised us since then is how much we’re saving on gas every month.”

On average, Countryside High School saves close to 20% on their monthly utility bills since switching to the Demand Duo units. The commercial ENERGY STAR® certified tankless units offer 96% thermal efficiency, yet deliver more stable temperatures and more hot water than the previous system.

Crawford expects to reap more savings over the long run, thanks to the Demand Duo’s dependability and serviceability.

“They’re worth their weight in gold, because they’re so reliable and easy to maintain,” said Crawford. “I don’t have to babysit them all the time, like we did the old water heaters. I was spending a ton of money keeping the old units up and running.

“Rinnai even taught a free, on-site class for my shop people on maintaining and servicing the Demand Duo,” Crawford continued. “So, if the heat exchanger ever does fail, I can swap it out for a fraction of the cost of new water heaters. And with the redundancy of the units, we never lose hot water, even during servicing.”

More Schools, More Demand Duo Units

Since October of 2016, when the Countryside High School installation took place, the Pinellas County School System has replaced tank-style units in another seven schools with Rinnai’s Demand Duo Hybrid Water Heating Systems. Tempaco’s Johnson said that more Demand Duo installations are likely in the future for Pinellas Schools, as more old water heating systems fail in other schools.

“We’ve seen the track record with these units now,” said Crawford. “We simply don’t have issues with them. We’ve had zero problems — and not a single complaint from our schools — in the first year of use.”