Heat Pumps and Gas: North vs. South

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A homeowner has options for heating his pool — electric, solar, gas, heat pump or he can just wait until the summer sun takes effect — but for a good portion of the overall market, the choice comes down to the power and immediateness of gas versus the plodding efficiency and cost savings of a heat pump.

As with other components in a pool system, there's no single "best" solution for all applications; it's just a matter of finding the right heater for the particular job — or perhaps more accurately, for the particular family of swimmers. And that's where a thorough discussion with the customer becomes essential, a discussion which starts with thoughtful questions:

Why is the heater being purchased? Are we extending the season to get the kids out of the house on the first day of summer vacation? Or is the pool merely an adult party venue six weekends a year? Is energy efficiency a driving factor? What about initial cost?

It's incumbent on the seller to force the consumer to think through the purchase, while augmenting the process with the seller's own understanding of the technology, especially how the vagaries of the local climate will impact performance. Conditions like ambient temperature, humidity and length of swim season have a powerful influence on the eventual outcome of this deal. We asked two manufacturers' agents who work in the same products, one in the frozen North, and the other in the sunny South, how the heater story changes when the latitude drops.

Northern Approaches

The pool heating equation looks a lot different up North than along the sunny beaches of Florida.

Eric Gabrielson lives north of the Mason-Dixon line and sees the issue from a Yankee perspective; he works in New England for Raypak. His territory contains a healthy share of large, upscale gunite pools owned by suburbanites who make a very comfortable living in the city.

"These people aren't too concerned about what it's going to cost to heat their pool, they just want it hot, and right now, so it's a gas community. For them, it's not really a financial decision, it's a decision about making the pool the temperature they want, when they want. 'Gas will do that? OK, let's get a gas heater.'

"Some of these customers are only looking to use the pool three or four weekends a year — Memorial Day, Fourth of July, Labor Day, perhaps a graduation party. The gas heater makes it easy. They just flip a switch on Thursday or Friday, and it's ready for the party on Saturday. You use the pool on the weekend, and turn it off. Because a gas heater, properly sized for that homeowner's wishes, will have that water ready in 12 to 24 hours. That's what they want, and gas delivers it."

Now due to the local climate, the heat pump market is relatively small in Gabrielson's region. Heat pumps are at their best when there's a lot of ambient heat to pump, and above the 40th parallel, the potential for a cold snap or even an extended period of cool weather can suddenly turn a heat pump into a lukewarm pump. And there's nothing worse than turning on your heater, and then shivering in cold water next to an outlet cranking out tepid water.

In addition, the heat pump works better if it's not running 24/7, which shortens its life.

These problems limit the heat pump market somewhat, but there are still customers drawn by the heat pump's undeniable efficiencies in warm weather. These customers live beyond Gabrielson's gunite neighborhoods, in vinyl-liner territory, and look at heaters differently.

"These are budget-conscious customers who have spent their vacation money on their pool. So they're going to be out there the whole summer, June, July, August and September, and they want that pool to be at a set temperature and ready to go because that's their entertainment. That's their getaway. Weekdays, weeknights, weekends, all summer, they want that pool ready. The heat pump can be good for that situation, and that type of customer is ready to listen to a pitch for a heat pump."

While he can make a heat pump sale to a budget-conscious customer now and then, Gabrielson figures that gas will stay dominant in his area for the foreseeable future due to a variety of advantages. "Up here in the Northeast, we have a shorter season, and we often have bigger pools with a bigger surface area, and that means more heat loss due to evaporation. So these things make an argument for gas over heat pumps for many customers."

Southern Climes

Down in Florida, where Gabrielson's colleague TJ Redman works the heater market, the climate is much more favorable for heat pumps, and they grab a much larger share of the market.

With the bright sun beating down on the heat pump, warming its coils, the technology makes a more convincing case with greater efficiency and its ability to maintain a set temperature relatively cheaply.

For those customers, he says, "the pool is a big investment, and there are lots of days early in the swim season when you're looking outside, the sun is shining, birds are chirping in the trees, the kids are beating the dog and you're dying to get out there, but you stick your toe in the water, and you say, 'There's no way I am getting into that pool. It's just too cold.'"

Redman is thankful for the fact that people who live in a warm climate become sensitive to temperature and end up thinking about heating a pool above the temperature provided by the tropical sun.

In time, this hot-water-delicacy even claims the state's many immigrants from the North, he says. "I don't care if your last name is Claus, and you moved down here from the North Pole, if you live down here long enough, your blood starts to thin, and you become more sensitive to cold. Your expectations start to rise on what temperature that water needs to be before you can get in it."

"And that's when they turn to us," he says with an audible smile, "the heater people."

When they do, customer education about heater technology is crucial. In that process, Redman is especially adept at building knowledge through simple, everyday concepts.

The purchase of a heater is very much like the consideration of what car to buy, he says. And while few consumers would get all the way to the sales manager's office before thinking about two doors versus four, or sedan versus SUV, without some guidance, a pool owner may move on impulse toward a friend or neighbor's solution without thinking the purchase through, or asking introspective questions such as:

When it comes to a heater, do I want a Trans Am or a hybrid?

"Trans Am versus Toyota Hybrid — that's one way to put the concept across," he says. "Whether I'm talking in one of my classes or at a trade show or just sitting one on one with a customer, I make sure to use concepts they already understand.

"I like to say, 'We need to get up to 60 miles an hour. That's how fast you want to go. We can do it in a Trans Am, or we can do it in a Hybrid.' In the Trans Am family, mom and dad get home on Friday, and they say, 'Let's do some swimming this weekend.'

"That's a Trans Am, gas heater family, not a heat pump, Toyota Hybrid family. You can't turn on your heat pump on Friday and expect to be swimming on Saturday. Not going to happen."

The Hybrid family, on the other hand, is out there using the pool every day, he says. They might have a kid on the swim team, or maybe they're using the pool for therapy, and they want that temperature constant. If they try to heat that pool with gas, they can really burn through some money fast.

The analogy extends to budget attitudes as well. "Gas prices are not as important to the Trans Am owner," Redman adds. "More than anything else, that customer just wants to get to 60 miles an hour as fast as possible. It's worth it to that owner. The Toyota hybrid owner needs to get to 60 but doesn't care so much about how fast — that customer just doesn't want to pay too much at the pump."

In summary, Redman says, neither system is the savior of the pool; they both have their place. And whether you live in snow country or beach sand country, "the best thing a dealer can do to avoid an unhappy customer is just talk to the customer before you ever get to the quote, find out what their realistic budget is, what they're expectations are and what they're looking to do," he says. "These are the basic questions that need to be asked so the customer ends up with what they need."


Comparing Heat Pumps and Gas Heaters

Heat pumps:

  • Higher initial cost
  • Longer heat up time, heat output affected by ambient temperature and humidity
  • Lower energy cost
  • Highest efficiency (usually between 500 to 600 percent)

Gas heaters:

  • Lower initial cost
  • Very quick heat up time (dependent on heater size), heat output is always constant regardless of conditions
  • Higher energy costs
  • Lower efficiency (82 to 94 percent)


There's a Hole In The Bucket

The pool heating process may be likened to many things, but it resembles nothing so much as a bucket — a bucket of heat. And one can think of the desired swimming temperature as a level mark on the inside of the bucket.

The forces that warm the pool — sunshine, hot summer air, and a pool heater, work like faucets, pouring heat in, raising the level of heat. Sunshine and ambient temperatures are just dripping faucets; it will take them a long time to reach the mark. A gas heater is an open tap: it fills the bucket quickly, while a heat pump produces a reduced stream.

But all the buckets leak. Every single one. They all leak heat through convection and conduction and radiation, but especially evaporation. And it may occur to some to wonder why — why does evaporating water, a liquid simply changing state, steal so much heat from a pool? It's because of a physical property called the "latent heat of evaporation."

A liquid water molecule doesn't just get warmer and warmer in a linear fashion and then leap into the air as a gas. It sits as a liquid and gathers a large amount of heat energy for a sudden transformation to the vapor state. That latent heat it gathers comes from the pool.

It's why evaporating water on your skin feels so cold. That evaporating drop is sucking heat out of your body the same way it sucks heat out of a pool.

This is important because the right heater for a job partially depends on the measures that will be taken to reduce evaporation. If less heat is leaking out of a pool, less needs to be added to make up the difference and keep the total heat at the level mark.

Because evaporation is so important to pool heat, one of the The biggest drivers of heat loss is wind. A pool in a windy location will have much greater pool heater demand than a pool in a generally calm location, as that wind works like a blow-dryer to promote evaporation. This is an often-overlooked factor in the pool heater calculation.


Comments or thoughts on this article? Please e-mail [email protected].

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