Heat History

Global warming. Volatile organic compounds. Climate change. NOx emissions. Energy Star.

It wasn't that long ago that these terms were rarely if ever heard in the pool business, but these days, environmental concerns and fuel scarcities are perhaps some of the first things that come to mind when talking about pool heating. We often write about imminent regulations and the pressure to make ever-more-earth-friendly heating products. These are excellent - and necessary - goals, and we'll continue to track the industry's achievements in caring for the earth and conserving its resources. But here at AQUA Magazine, we're pool-half-full kind of folks, so this time we thought we'd look back a few years and celebrate the progress we've made so far.

When former managing editor Elissa Sard Pollack wrote "Heat Wave," in 1996, she asked service technicians to talk about the thennew features in heater design that they liked best. Ten years later, we asked Ed Penfield of Aqua Island Technologies to comment on those innovations and on heating progress made over the past decade. Penfield is a certified building professional, a certified service professional and vice chairman of the APSP Service Council.

The Way It Was

First, a little history. The use of natural gas for heating is a relatively recent development. Although ancient peoples were aware of this natural resource - especially when it seeped from fissures in the earth and ignited - they had no explanation for it and often considered it mysterious or divine. According to the Natural Gas Supply Association (and probably your high-school history teacher, too), one of these flames was found in ancient Greece on Mount Parnassus around 1,000 B.C.

The Greeks, believing the flame to be of divine origin, built a temple on the flame. This temple housed a priestess who was known as the Oracle of Delphi.

Still, two things had to happen before natural gas could be easily and safely used. Someone had to figure out how to deliver it to users, and someone had to figure out how to control the combustion.

According to naturalgas.org, the NGSA's web site, in 1885, Robert Bunsen invented what is now known as the Bunsen burner. His device mixed natural gas with air, creating a flame that could be safely used for cooking and heating. This invention opened up new possibilities for the use of natural gas, and the invention of temperature-regulating thermostatic devices allowed for better use of the heating potential of natural gas, allowing the temperature of the flame to be adjusted and monitored.

It wasn't until 1938 that the U.S. government first regulated the natural gas industry and an infrastructure for delivering the fuel began to reach homes. And it wasn't that long ago that a heated residential pool was quite an extravagance. Today, as we all know, heater sales and service comprise a noteworthy percentage of the industry.

Heat Then And Now

Some of the features that impressed service professionals in 1996 are considered standard on today's models.

Dual thermostats, electronic ignition, diagnostic lights, lighter and smaller heaters that are easy to install, improved access for servicing, and standardized parts were at the top of the list just a decade ago.

Dual Thermostats

1996: Because heaters are most often used for pool/spa combinations, it makes sense that they would come standard with two thermostats. But this hasn't always been the case. As recently as [1993] installers had to special-order kits if they wanted to offer their customers separate thermostats for the spa and the pool.

Dual thermostats are a real plus, says Rick Joslin, owner of Sunrise Pools of Naples, Fla. In addition to the obvious benefit of having two thermostats for the two bodies of water with different ideal temperatures, Joslin points out a servicerelated advantage. Evenscala figures on pools that don't have spas, if one of the thermostats needs to be replaced, the other one can serve as a backup so the pool can still be heated until the repair is completed."

2007: "When it comes to electronics, as far as I know, they all come with dual thermostats now," says Penfield. "Now there were some . I just took one out, what a monster . that had a toggle switch so if you're going to be gone, and you really don't want to heat the pool, but you don't want it to be too cold when you return, just flip the toggle to low. "But I didn't want to take this one apart because I thought it should go in a museum. They took the sensor probes and they soldered them in! This was just one of those Model Ts."

Lighter Heaters

1996: "When the MiniMax heater hit the market in 1991, it drew attention for several reasons, says Dale Coats, Purex/Triton's [now part of Pentair Water Pool and Spa] national training director. "Its lower profile makes it easier on retrofits because it fits in places other heaters don't, and it doesn't take two guys to install it."

Replacing the traditional sandstone fire brick insulating layer in most gas heaters has made several other models lighter in recent years, too. 'Heaters that used to weigh 350 pounds now weigh 150 pounds,' says Erwin Matulka of Precision Pool in Valparaiso, Neb. He says this change also allows PVC plumbing to be used in and out of the heater because the excess heat that would ordinarily be too much for PVC is absorbed. On a related note, heaters with the newer heat-absorbing linings do not require the pump to run for 20 minutes after the heater is turned off, which is necessary on older designs to prevent hot water from melting the pipe."

The 1996 story also notes that Sta-Rite held off coming to market with a heater until a plastic design could be achieved. Steve Peake, product manager for Sta-Rite, said that injectionmolded plastic was the company's core capability and people used to laugh at the idea of a plastic heater. But Peake said that plastic allows the heater to be lighter and more compact, noting that one person would be able to carry the new heater.

2007: In 1996, when gas prices ranged from a low of $1.27 per gallon to a high of $1.46 per gallon, the primary interest in lighter heaters was because of the ease of handling them in the field. With fuel prices double what they were a decade ago, shipping costs figure more prominently today.

"Lighter ones are definitely a benefit," says Penfield. "Having the insulation block, which was a 21.2-inch block, like a fire brick, gave the heaters a lot of weight." Another problem Penfield recalls was breakage. "They never quite got the packaging down," he says. "When they arrived they would be broken and then you'd have to reorder. Today thermoplastics are designed into front and rear headers.

That, along with the addition of using refractory material, has made the heaters lighter. It's nice because you can lift them up and do something with them by yourself." Penfield figures that heaters have lost about as much weight as they are going to. "I don't know how they could go much lighter than they are."

Electronic Ignition

1996: "When it first hit the market [around 1990] electronic ignition had had its share of bugs to work out. Many service techs who were comfortable working with millivolt ignition where scared to work with live 110- or 220-volt systems.

Matulka says, 'With electronics you have to have a little more upstairs to work on them, but they're easier to work on. They may seem complicated, but the diagrams are easy to follow.'" 2007: "When you look at electronic ignition today, there are some designs that are much better than others," says Penfield. "Some have a spark ignition and some have an actual heated rod that causes ignition. A lot of times the rods can have problems; they warp or they are damaged and shut the systems down. There are advantages to electronic ignition. They make it nicer for the system, but not so much in longevity."


1996: "The new Sta-Rite heater boasts unprecedented service access because the top comes off . . . on Raypak's latest models, for example, the pilot light can be removed for inspection or replacement with a single screw. And only two screws need to be removed to release the burner tray." 2007: "The access to the equipment is much better, today" says Penfield. "The gas valve and the electronics are very accessible, it's easy to get in and work on components. But when it comes to replacing the exchanger itself, you might as well buy yourself a new heater." Not only is it difficult to access, but materials costs are such that it's not economical to replace it.

Heating The 21st Century

In 2007, manufacturers are continuing to make refinements and improvements and to respond to new regulations. Changes since 1996 often have to do with environmental and resource concerns, and changes to other parts of pool systems.

"Many pools are using salt chlorine generation, it's recommended that you use a cupro-nickel exchanger with salt water. Cupro-nickel exchangers are now out there and available and probably more [manufacturers] will be going with cupronickel or titanium."

New, Improved


Technological and cultural changes in the past decade have also had an effect on Penfield's customers.

"I have some customers who don't even have a salt-water pool, and they request cupro-nickel," he says. "They search the Internet and somehow they run across information like this. They are a lot more knowledgeable than they used to be."

While a well-informed customer is generally a good thing, it doesn't always work out that way. "They look at the Internet, they get somewhat educated that way, maybe just enough to get in trouble," says Penfield. "If there is a problem on a warranty issue, they have to call the people they bought it from. If I am a warrantee station for that particular model, then they may be eventually calling me. But that's the trend."

Men Asking For Directions?

Penfield has noticed another customer trend that surprises him. "I can't tell you how often I'll have someone - a male - tell me that he's just not mechanically inclined," says Penfield. "He'll say, 'I don't get it, I don't even want to mess with it.' Or 'I don't like maintenence. I don't want to maintain anything at all, so I want you to do it.' These are guys talking.

"They are more willing to admit that they don't understand, and they want somebody else to take care of it," says Penfield. " I have a customer who is a veterinarian. He says he doesn't understand his pool and he doesn't want to do the maintenance. But I'm sure he can do surgery on a dog a lot better than I could. He's OK with not wanting to deal with it. He has his own specialized area. The world has changed that way."

Penfield's Picks

Penfield shared few favorite features that are available on 21st century heaters. "Power venting. Say you are working with an undersized heater and you have to put a new, larger one in. You're going to have to change the whole flue system if it's not power vented," he says, adding that smaller flue sizes, more-controlled burn and usually higher efficiency are other benefits of power venting. "You can retrofit easier with less expense for your customer."

With new new systems come new problems, and a new service challenge that Penfield sees is condensation on the super-efficient units. "The heaters in the '60s and '70s and '80s would be eaten away from the inside-out by aggressive pool water," he says. "Now, a lot of times, the damage is coming from the outside-in. That all started with the efficiency race.

"Because they are so tightly designed, everything has to be at its optimum level: gas supply, fresh air and combustion air venting, flue size and location. It has to be closely watched. The old ones didn't have efficiency, but you could put them in and they'd just run and run and run."

What's Next?

Penfield has a few ideas for the next wave of pool heating systems. "Maybe they make this and I don't know about it, but I would like to see a hybrid gas heater/heat pump for a pool," he says. "They make them for residential heating.

"You'd run off the heat pump until it can't produce an adequate amount of heat and shuts down. Then it would kick in and use the gas, and you've got the best of both worlds. "The other thing is that in some places it may get cold in the winter where you need the gas heat a little bit, but it gets hot in the summer, and you could reverse the system and chill the water."

Check back in 2016 to see if Penfield gets his wish.

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