Published by United Media Group, Melbourne Pool & Outdoor Design Magazine, Issue 11.
Without a cover, your pool will lose water and heat while gaining dirt and debris. Rachael Harrington looks at the options available to cover all bases. Given your pool is a considerable investment, it is important that you get the most out of it, and reduce further costs. A pool cover will not only benefit your hip pocket, but the environment too. Plus, the variety of options available means you’re sure to find something that suits you, your pool and your budget.
WHY COVER UP?
A pool cover is a simple and effective way to reduce water evaporation in your swimming pool. According to the Swimming Pool and Spa Association of New South Wales (SPASA NSW), an average pool can lose up to 5mm of water every day to evaporation. This equates to approximately 1.5 metres per year in the Sydney metropolitan area. Evaporation most commonly occurs at night time, when the ambient air temperature drops below the temperature of the water in the pool.
You can save water by significantly reducing the evaporation of your pool by using a pool cover. According to SPASA NSW, regular use of a cover can potentially reduce evaporation by 95 per cent.
As well as preventing water loss, a pool cover can also prevent heat loss from occurring. Heat transfer is an inevitable consequence of contact between objects of differing temperatures, like a pool and the outside air. Thermal insulation reduces heat conduction, where internal energy from a region of higher temperature flows to one of lower temperature. SPASA NSW has found that 90 per cent of heat loss is from the surface of a pool. Covering a pool’s surface can therefore save money by reducing pool heating costs by up to 50 per cent. It can even increase the pool temperature by 6-8°C in pools that receive sunlight, therefore extending your swimming season.
A pool cover will not only keep your pool full and warm, but it will keep it clean. Debris commonly found in pools, such as dirt, leaves and insects, can be blocked by a well-fitting pool cover. This reduces the workload on your cleaning system and reduces the need for any manual cleaning. Improving the water quality by keeping out debris and reducing the amount of chlorine lost to the sun’s UV rays will also save on the cost of pool chemicals.
HOW DO COVERS DIFFER?
Bubble Covers/Solar Blankets
Perhaps the most well-known type of pool cover is the bubble cover, also known as a solar blanket. These covers float on the surface of a pool and are usually made from a synthetic polyethylene material. Resembling a heavy-duty form of bubble wrap, these covers allow maximum solar energy to penetrate the pool and warm the water, with the air-filled bubbles on the cover working as an insulating layer to prevent warmth from being lost. It will also reduce the loss of water in the pool due to evaporation.
Solar blankets are available in a variety of colours and a wide range of sizes and shapes. If a pool is unusually shaped, solar blankets can be cut to fit. As these covers need to be removed regularly, a roller or hideaway system is advisable.
Another type of covering available is the thermal blanket. These are designed to insulate pools overnight by reducing evaporation and heat loss.
Thermal blankets are designed to endure higher temperatures, made with an inner layer of foam and an outer layer of hard-wearing bonded laminates. They are lightweight, flexible and durable. Thermal blankets claim to eliminate over 90 per cent of water loss through evaporation and last for around ten years.
Sunlight is what assists algae growth, so using a thermal blanket to block out sunlight and keep your pool dark can reduce your chemical usage and maybe even filtering hours. While not as thick as a bubble cover, a roller can still make these covers more manageable. Both manual and automatic systems are available for removing thermal blankets when you want to use your pool.
Liquid covers are a more recent innovation in pool covering, appealing to those who don’t like the appearance of a pool cover, or are conscious of the space that they require. Liquid covers work by forming a liquid barrier on the surface of the pool. Liquid chemicals are added to a pool by hand or by using an automatic dispensing system. The chemicals form an invisible barrier on the pool’s surface to limit the escape of water vapour, thus reducing evaporation.
Liquid pool covers are made from biodegradable ingredients that are able to slow heat loss and evaporation, without affecting the chemical balance of the pool. The silicon-based chemicals used are non-toxic and therefore harmless to pool swimmers. The amount of time that the liquid lasts for varies depending on the particular product used, but can last between eight and ten weeks.
Slat pool covers operate in a similar way to a roller garage door, rolling out onto the surface of a pool. When the slats are fully extended, they lock together to form a strong barrier. When fully closed, some slat covers can sustain the weight of approximately 80kg, thus providing extra safety for small children or pets.
Slat covers provide a solid, impenetrable surface to the pool that prevents debris from entering the water. Any collected debris is fed into the skimmer boxes when the cover retracts, keeping the pool clean. These covers are also thermal insulators, reducing heat loss and evaporation. When slat covers are selected for new pools, they can be installed below ground, totally concealing the device when not in use. Slat covers can also be used on existing pools, with above-ground installations.
Whichever type of pool cover you choose, it will help to save water, energy consumption, costs and cleaning time, making it a rewarding investment to help you get the most out of your pool.