Swimming Pool Energy Audit: Taking Stock of Inefficient Equipment

—3 ways to cut your pool’s power consumption and save on operating costs

Swimming-pool ownership brings fun, healthy personal rewards, and you shouldn’t let concerns about energy bills dampen any enjoyment from those terrific benefits.

Why? It’s relatively easy to improve your pool equipment’s energy efficiency. By putting some effort into reviewing the systems on your existing pool, you may find some key opportunities to do so.

Likewise, if you are planning on building a new pool, then making informed choices about the components to purchase will deliver similar benefits.

To get the biggest boost, focus on model choices for your pump, heater, and lighting system. Strategically upgrading aging equipment can make your pool kinder to the environment and more economical to operate.

1. Your pool pump 

An integral piece of technology that creates water flow, the pump serves as the heart of your pool’s equipment system. This vital organ controls circulation and filtration, as well as functions such as spa jets, water features, and some kinds of automatic pool cleaners.

In the process of making all this happen, the pump consumes electricity. In fact, your pool pump likely uses three times as much electricity as your refrigerator. Depending on what part of the country you live in, your pool pump may add $300—or even up to $1,000—or more per year to your energy bill.

If your current unit is what’s known as a single-speed model, then going forward you have better options. If it’s coming due for retirement and you’re looking to cut utility bills, consider replacing it with a different kind of model that gobbles less energy.

To understand more, let’s look at traditional single-speed models versus multi- or variable-speed ones. Single-speed pumps operate at only one setting—no matter what function they are performing. As a result, they require a lot of power.

Here’s the reason: Not all pool functions require the same amount of water flow. For example, spa jets require high pressure and minimal flow. But functions like circulation and filtration call for higher flow at lower pressure levels. That’s where multi- and variable-speed pumps can help save electricity.

A multi-speed pump has two settings. As needed for the particular function, it can switch between high and low speeds. When the pump runs on low, it uses only the minimum amount of energy needed. So this is how the savings occur.

An even better upgrade option is a variable-speed pump. With an infinite number of speed levels, it delivers maximum efficiency.

This versatility allows the variable-speed pump to adjust the water flow to precisely the speed needed to run each function. Most have built-in timers that allow you to create a schedule that addresses the different pool functions.      

Replacing your pool pump with a multi- or variable-speed model is a very smart move for both your budget and the environment. Now, the initial purchase price will cost more than a one-speed pump. However, over time, the savings on your monthly utility bills will make it more than worth it.

2. Your pool’s gas heater

Gas heaters are great for warming pool water to comfortable levels and for quickly firing up a spa to a relaxing temperature. If you’re looking to add a heater or replace an older one (or, if you are choosing one for a new pool), you have two key factors to keep in mind.

First and foremost, is the heater’s rating for thermal efficiency. This rating measures how effectively the heater uses gas to generate heat. Top-brand heaters typically offer a thermal efficiency of 82 to 84 percent.

When shopping for an energy-wise unit, look for one with an efficiency rating in this range. Also, check that the rating is backed up by third-party certified testing; it should say so on the box in the manufacturer’s product description.

The second factor is the unit’s size—which relates to its power output. You measure the size—or power—of a heater in units called BTUs (British Thermal Units). For pool heaters, the typical range for BTUs is 150,000 to 400,000.

Your heater size—measured in BTUs—is critical, as it will affect how long the unit will need to run to achieve the desired temperature. And in some cases, an undersized unit—explained below—can waste energy.

First, when determining the proper size heater for a pool, you want to consider the pool’s size regarding its surface area. For example, a pool that’s 15 feet wide and 30 feet long (a fairly small one) contains a surface area of 450 square feet.

To reach the desired temperature in a reasonable amount of time, a typical 450-square-foot pool (with no spa) requires a heater that’s 150,000 BTUs.

But try using this heater on a pool that’s a little larger—say 550 square feet—and you could have problems: It may never achieve the desired temperature.

That’s right; a greatly under-sized model will run and run without ever getting the job done. So, you need a heater that’s the right size for your pool. That means it’s large enough to produce the needed heat output efficiently.

Spas change the heating equation as well. If your pool has a spa, your heater needs to be larger. Because spa users will want the water hotter (around 100 to 104 degrees Fahrenheit) and for it to heat faster, spas require more powerful units. Average-size pools with a spa typically require a model that’s at least 250,000 BTU.

Keep in mind that other factors beyond pool size affect how much power your heater needs. A low-humidity climate is one. Dry air speeds up water evaporation, which causes up to 70 percent of a pool’s heat loss.

Another variable is an often-windy backyard. Like dry air, wind cools pool water and speeds evaporation. In fact, a 7-mile-per-hour wind can cause enough heat loss to triple the energy demand on a heater!

The lesson here: Never shop for the cheapest heater. Rather, seek the one with both a high thermal efficiency rating and the proper size (BTU power) appropriate for your particular pool and spa. Doing so will ensure that it achieves the needed heat output with less energy use and in a shorter amount of time.

3. Your pool lighting

Are you still relying on old-fashioned incandescent or quartz halogen light bulbs in and around your swimming pool? (Or, are you in the process of building a new pool and choosing a lighting system for it?)

Well, you have several great reasons to opt for LED (Light Emitting Diodes) illumination instead of traditional light bulbs.

First and foremost, LED technology offers superb energy efficiency. In the last few years, LEDs have come onto the market for home use, and today, they have made it to the backyard and pool as well.

LEDs clobber incandescent lighting when it comes to electricity consumption. White LEDs create the same light output as an incandescent bulb (colored LEDs are somewhat lower) while using 50 to 75 percent less energy! It’s no wonder their popularity has skyrocketed. 

Yes, the initial cost of a 40-watt LED light runs more than a typical 300-watt incandescent bulb or halogen light. However, the lower-wattage LED lights can save up to eight times as much in annual electric bills compared to incandescent lights—five times as much compared to halogens.

The second advantage to LEDs is their longevity. LED lights use semiconductor technology with a lifespan that far exceeds their incandescent or halogen counterparts. They last for tens of thousands of hours before replacements are needed!

Because you won’t have to change burned-out bulbs as frequently, you will save money—not only on the bulbs but on the cost of hiring pool techs to replace them.

Another benefit of LED lighting is the visual drama it produces. They bathe your pool, spa, and water features with blues, reds, whites, greens, golds, and magentas. Best of all, LEDs deliver stunning impact in your backyard and do so using less energy than traditional pool lighting.

Peace of mind—for Mother Nature and your wallet

An audit of your existing equipment can help you make new technology choices that make your pool “greener” in a good way.

Ensuring that your pool’s pump, heater, and lighting and are energy efficient may take a few hours of research and shopping, and it will certainly require an upfront investment. But in the big picture, this will be time and money well spent.

Modernizing key pool components will deliver better performances with lower power use. That’s better for the environment and on your bottom-line operating costs.

If you’ve got the right equipment in place, you have no reason to worry about anything when kicking back at the pool—except maybe how many hot dogs to toss on the grill, and if you have enough buns.