In this article, you’ll learn how your pool company can maximise the efficiency of your hydraulic systems. You’ll discover that a well-engineered plumbing design will reward you with years of reliable service and consistently stable water conditions.
Just think about it, if you owned a pool company, would you spend more time trying to reduce your clients’ running costs or would you focus on reducing your own construction costs to appear more competitive? Morally, we like to believe the client always comes first; in contrast, many pool companies are driven by current business matters rather than your needs. And although one concrete pool builder may appear cheaper than the next, the additional running cost of a poorly engineered pool can quickly eliminate any advantage gained by superficial upfront savings.
It’s a fact, you will save money and enjoy reduced maintenance if pool companies direct more energy into designing you an efficient circulation system, particularly if site conditions are challenging.
The Importance of Circulation and Turnover
Circulation and turnover are interrelated. Nevertheless, it’s important to understand the fundamental differences between the two. Just imagine you’re making a coffee. You add the coffee, milk, sugar and water. Then you stir the coffee to circulate and evenly mix the ingredients. When you drink your coffee and pour yourself another cup, you have turned it over. Therefore, circulation is defined as the continuous movement and distribution of water around your pool and turnover applies to the frequency in which water is drawn through your filter and returned to the pool.
An effective water management program consists of the following
- Good filtration and circulation
- Good water balance
- Good water chemistry program
- Good maintenance habits
Good water balance and maintenance programs are your responsibility; however, issues can arise due to inefficient hydraulics. Low water velocity combined with inadequate circulation and filtration times can affect water quality despite a vigilant maintenance regime. So, designing a system fitting your specific circumstances is the key to success.
What Causes Reduced Velocity and Turnover?
Water velocity and subsequently turnover is reduced by friction and resistance within your system.
Sources of friction and resistance are:
- Your accessories and the number of components installed.
- Your equipment’s proximity to your pool and pipework length.
- Pipe width and thickness.
- Irregularity in your pipe’s direction and the severity of those bends.
- Accumulated debris in your filtration system.
- Gravity.
- Air in the system.
Even water velocity creates friction; and resistance increases as flow rates are increased. Additionally, your pipes internal surfaces may begin to erode when flow rates exceed 3.8 metres per second on discharge and 1.8 metres per second on your filter’s suction side.
Contrary to popular belief, simply bolting on a bigger pump for maximum velocity isn’t always the right answer. This is not to say larger pumps shouldn’t be used where appropriate. However, compensating for a poorly designed system by adding more horsepower will significantly and unnecessarily increase your power consumption.
Complicating matters further, high water velocity reduces filter efficiency because the media captures debris more effectively at lower flow rates. It’s a vicious circle; you’re paying extra to run a powerful pump and although turnover rates are faster, you’ll require longer filtration times to achieve the results produced by lower velocity systems.
Variable Speed Pumps
Incorrect use of Variable speed pumps can also cause problems. Manufactures claim huge power savings (up to 70%) by running pumps on low speed settings. And the fact is they will save you money. However, many people including pool builders set these pumps to low speed and fail to increase filtration times to compensate for reduced water velocity. This can culminate into dirty, green water because turnover and circulation isn’t enough to adequately sanitise your water.
Adding Additional Equipment to an Existing Filtration System
Load increases and turnover falls when you add more equipment like salt chlorinators, chemical controllers, solar heaters, gas heaters, suction cleaners and water features. Increasing either filtration times or pump size may be necessary to compensate for reduced flow rates.
You’ll achieve superior results by disconnecting suction cleaners as soon as your pool is clean. A suction cleaner shuts down your skimmer and adds enormous load to your hydraulics. It’s preferable to remove surface debris with a functioning surface skimmer before it sinks and potentially causes staining.
By now you‘re beginning to understand that a well-designed hydraulic system is a balance between correctly sized equipment, efficient plumbing layouts and sufficient running times. Your pumps need enough power to overcome the resistance within your circulation system but not so powerful that filtering efficiency is lost and energy is wasted. Your pumps need to run long enough to achieve adequate turnover while suctions and returns should be positioned to maximise circulation.
When you buy a Bespoke Pool your filtration system will be designed utilising mathematical formulas to ensure your hydraulic system is perfect for your specific site conditions. Concrete pools with well-designed hydraulic systems are easier to maintain, look cleaner, achieve superior water quality and are more economical to own.