Earth-Friendly Pools
by John Watt
When building a green home, don't forget the backyard. Technology innovations that have led to efficiency gains throughout the home are now being adopted by Arizona swimming pool builders. Considering that the average swimming pool filter pump will use more electricity than any other appliance in the home, builders concerned with energy efficiency will want to take a good look at how Arizona's most essential backyard accessory is built.
With well over 300,000 pools, Arizona has more pools per capita than any state in the union-a swimming pool for every 20 residents. It's difficult to imagine building a high-quality home in Arizona without a pool in the backyard, but with continuously rising energy costs, potential state regulations and increased interest in making homes more environmentally friendly, there is an immediate need to lower the operating costs of pools. Fortunately, there are several opportunities to reduce pool energy usage and save home owners hundreds of dollars per year.
Pumping Out Energy Savings
In California, the recent California Energy Commission's Statewide Appliance Saturation Study determined that pool pumps are almost always the largest single electrical end-use appliance in a home. A study least year by the National Resources Defense Council (NRDC) examined pool usage in Phoenix and determined that the average pool owner spends roughly $350 each year on pool pumping.
The NRDC also found that upgrading to a variable speed pump reduces annual pumping costs by an average of $280, and further upgrading to a high efficiency heater delivered total savings of $390 per year. Building an entire home to Energy Star standards typically delivers annual savings of $509.
Most pool pumps have used single-speed motors, often with undersized plumbing and filters that strain the pump. Today's multi-speed pumps are increasingly common, and they provide options for greater efficiency. In fact, variable-speed pumps offer efficiency gains up to 90 percent over a single-speed motor.
In a typical one- or two-speed pump, motor speed is almost always locked at too high of a flow rate, which wastes energy. Automobiles provide a good analogy: It is more efficient to drive at 55 miles per hour than at 70 miles per hour, even if it means more time on the road. The best variable speed pumps can be programmed for the requirements of each pool task, which is anywhere from 400 rpm to 3,450 rpm. Some models feature a similar range but limit the pump's flexibility to six settings. This is still more efficient than typical pumps.
Because of this new technology, pool professionals have had to change the way they view pump power. The horsepower measure simply doesn't apply. A standard pump weighs in at one- or two-horsepower, while a variable speed pump is actually a zero- to two- or three-horsepower pump. This varies by manufacturer, granting that zero is only technically accurate if the pump isn't running; the low end is really a small fraction of a horse above zero.
When paired with automation software, the pump can automatically respond with additional power for cleaning, spa operations, waterfalls or fountains and then dial back the power for filtration duties. It doesn't matter whether the pool usage calls for one horse or three because the pump is programmed to adjust automatically.
The slower speeds are not only more energy efficient, they are quieter and better for associated equipment such as filters and chlorinators. The noise reduction has proven to be tremendously beneficial for homes in zero-lot-line neighborhoods where pool equipment may be located directly beneath the bedroom window of the homeowner, or worse, a neighbor's window.
Control Systems
Digital automation systems allow pool owners to schedule cleaning, filtration and temperature for pools and spas. Similar to automation systems found inside the home, pool control systems ensure that equipment will never be operated at a higher level than necessary or left running accidentally.
Homeowners can also program these systems to take advantage of off-peak utility rates or to optimize functions during times of heavy or light use. Interface options include wireless remotes, wall-mounted LCD touch screens or even iPhone applications.
Heaters
When former Vice President and environmental activist Al Gore renovated his Nashville home to meet the highest green building standards, one of the areas of top concern was his pool. In addition to many of the technology upgrades available, Gore utilized a geothermal heating system that was able to conduct heat from the ground into the water pipes to heat the pool. In many regions of the country, these ground source heat pumps are ideal alternatives to traditional heaters. An air source heat pump is a more efficient choice that can be found in Arizona.
Solar pool heating has also been shown to reduce heating costs significantly. Solutions range from rudimentary solar covers to photovoltaic cells, however, the most efficient options can be expensive.
Salt-Chlorine Systems
An automatic chlorine generator is another popular option, utilizing onboard electronics and automation technology. A chlorine generator converts ordinary table salt-roughly a teaspoon per gallon-into sodium and chlorine through a process known as electrolytic chlorine generation.
This amount of salt is lower than the human taste threshold but it allows the homeowner to forego the cost and risk of transporting, handling and storing chlorine in its standard chemical form.
The lower flow rates of a variable speed pump are compatible with a chlorine generator, as it is difficult to move water for skimming purposes while not creating enough motion for chlorine generation.
LED Underwater Lights
For pool lighting, LED pool lights are a much more energy-efficient option when compared with traditional incandescent and halogen pool lights. Also, LEDs are more durable and last longer than traditional incandescent bulbs.
Today's pool technology presents several opportunities for making pools more energy efficient and environmentally friendly. Offering greener pool options will allow home buyers to feel better about the choices they make, and they will enjoy the savings for years to come.
John Watt is a Regional Product Specialist for Pentair Water Pool and Spa based in Phoenix.
