Solar Heating – Is It Worth It?

Solar heating, is it worth it? A loaded question really. As with everything related to pools, pool design, pool surface type, sanitation options, filtration options, auto cleaners and heating options, they all rely on customer expectations and the economics of realising these expectations for the outcomes to be achieved.

I will address all of the above in future blogs as we have with pool heating in general. We did not consider solar an option in the pool heating blog, as it is not a stand-alone system that can offer acceptable commercial swimming water temperature during winter. Solar heating is sometimes marketed in conjunction with gas or electric heating as a boost to the main heating systems.

You can significantly reduce swimming pool heating costs by installing a solar pool heater. They're cost competitive with both gas and heat pump pool heaters, and they have very low annual operating costs. Actually, solar pool heating is the most cost-effective use of solar energy in many climates.

How it Works

Most solar pool heating systems include the following:

A solar collector - the device through which pool water is circulated to be heated by the sun

A filter - removes debris before water is pumped through the collector

A pump - circulates water through the filter and collector and back to the pool

A flow control valve - automatic or manual device that diverts pool water through the solar collector.

Pool water is pumped through the filter and then through the solar collector(s), where it is heated before it is returned to the pool. In hot climates, the collector(s) can also be used to cool the pool during peak summer months by circulating the water through the collector(s) at night.

Some systems include sensors and an automatic or manual valve to divert water through the collector(s) when the collector temperature is sufficiently greater than the pool temperature. When the collector temperature is similar to the pool temperature, filtered water simply bypasses the collector(s) and is returned to the pool.

Solar pool collectors are made out of different materials. The type you'll need depends on your climate and how you intend to use the collector. If you'll only be using your pool when temperatures are above freezing, then you'll probably only need an unglazed collector system.

Unglazed collectors don't include a glass covering (glazing). They are generally made of heavy-duty rubber or plastic treated with an ultraviolet (UV) light inhibitor to extend the life of the panels. Because of their inexpensive parts and simple design, unglazed collectors are usually less expensive than glazed collectors.

These unglazed systems can even work for indoor pools in cold climates if the system is designed to drain back to the pool when not in use. Even if you have to shut the system down during cold weather, unglazed collectors may be more cost-effective than installing a more expensive glazed collector system.

Glazed collector systems are generally made of copper tubing on an aluminium plate with an iron-tempered glass covering, which increases their cost. In colder weather, glazed collector systems—with heat exchangers and transfer fluids—capture solar heat more efficiently than unglazed systems.

Therefore, they can be used year-round in many climates. Glazed collectors also can be used to heat domestic hot water year-round.

Both glazed and unglazed collector systems should include freeze protection if they'll be used in colder conditions.

Selecting a Solar Pool Heater

A solar pool heating system usually costs between $4,000 and $4,500 to buy and install. This provides a payback of between 1.5 and 7 years, depending on your local energy costs. They also typically last longer than gas and heat pump pool heaters. Your actual cost and payback depend on many factors. Therefore, before you purchase and install a solar pool heating system, you should do the following:

Evaluate your site's solar resource

Determine the correct system size

Determine the correct orientation and tilt for the collector

Determine the system's efficiency

Compare system costs

Investigate local codes, covenants and regulations

Evaluating Your Site's Solar Resource

Before you buy and install a solar pool heating system, you first need to consider your site's solar resource. The efficiency and design of a solar pool heater depend on how much of the sun's energy reaches your building site.

Solar pool heating systems use both direct and diffused solar radiation. Therefore, even if you don't live in a climate that's warm and sunny most of the time -- like the south of the country -- your site still might have an adequate solar resource. Basically, if your building site has unshaded areas and generally faces north, it's a good candidate for a solar pool heating system.

Billabong Pool Service & Supply can perform a solar site analysis.

Sizing a Solar Pool Heater

Sizing a solar swimming pool heating system involves many factors:

  • Pool Size
  • Length of Swimming Season
  • Average Regional Temperatures
  • Desired Pool Temperature
  • Site’s Solar Resource
  • Collector Orientation and Tilt
  • Collector Efficiency
  • Use of a Pool Cover

Your Billabong Pool Service & Supply solar system consultant uses worksheets, aerial photography and computer programs to help determine system requirements and collector sizing.

The University of N.S.W. states that the collector square meter-age should be 100% of the pool's square meter-age to provide the best value for money and an efficient system, as most people would like to use outdoor pools 8 – 9 months per year. The use of a solar or thermal pool cover is strongly recommended.

In cooler, cloudier areas, or where the collector placement is not in the optimal compass setting or optimal tilt, you may need to increase the ratio between the collector area and the pool surface area. Adding collector square meters may also lengthen the swimming season.

You'll also want a properly sized pool pump for a solar system. If you're replacing a conventional pool heating system with a solar system, you may need a pump larger than your current one or a separate, smaller pump to move the pool's water to and through the collectors.

Siting a Solar Pool Heating System's Collector

Collectors can be mounted on roofs or anywhere near the swimming pool that provides the proper exposure, orientation and tilt toward the sun. Both the orientation and tilt of the collector will affect your solar pool heating system's performance. Our Billabong Pool Service & Supply consultant will consider them while evaluating your site’s solar resource and sizing your system.

Installation and Maintenance

The proper installation of a solar pool heating system depends on many factors. These factors include solar resource, climate, local building code requirements and safety issues. Therefore, it's best to have a qualified solar thermal systems contractor install your system.

After installation, properly maintaining your system will keep it running smoothly for 10–20 years. Consult your contractor and read your owner's manual for maintenance requirements. Your collector should require little maintenance if the pool's chemical balance and filtering system are checked regularly. Glazed collectors may need to be cleaned in dry climates where rainwater doesn't provide a natural rinse.

Screening Potential Solar Heating Contractors

Before hiring a solar heating contractor, ask shortlisted candidates the following:

Q. Does your company have experience installing and maintaining solar pool heating systems?

A. Choose a company that has experience installing the type of system you want and servicing the applications you select.

Q. How many years of experience does your company have with solar heating installation and maintenance?

A. The more experience, the better. Request a list of past customers who can provide references.

Q. Is your company licensed or certified?

A. While there is no governing body controlling Solar Heating installation. Confirm that your contractor has all the necessary insurances. A QBSA licence No. (For Queensland) is the minimum requirement for installations with a cost in excess of $3500.00. Your contractor’s affiliation with swimming pool industry bodies like SPASA should also be considered, as they can tell you about any complaints against the licensed contractors. Billabong Pool Service & Supply meet all the above criteria.

As with all of our blogs, we hope that it has been informative and it is of assistance to you. Feel free to visit or contact our Billabong Pool Service & Supply offices in Noosa, Maroochydore and Caloundra or through our webpage www.billabongpoolservice.com.au to get the best advice on solar heating for your pool.

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