Pipeless swimming pool – The low down on pipe free filtration
We have had a few customers over the past weeks ask about pipe free or pipeless filtration systems for their Compass Pool. We see several companies starting to offer this solution, we put in plain English the pros and cons of these systems.
Firstly lets get some myths out the way. There’s no such thing as a pipe free filtration system. Just one that’s all contained in one underground box. Within this box is contained a pump, a cartridge filter or bag filter and sometimes an electric heater joined with pipes. If you would like another form of heater other than electric (that we never recommend as a primary heat source due to the running costs) you will need to run pipe work to the heat pump or boiler. This is usually done in a trench just as a conventional filtration system as you don’t want it stuck next to you pool making noise and generating cold air! We always recommend that the plant room is located away from the pool as you don’t want the noise from the pumps near your swimming experience and you normally place them above ground to prevent the risk of the units flooding with high groundwater that we have recently experienced a lot of (winter 2013).
Probably the most important factor when designing a swimming pool filtration system is the electrical safety in and around the pool. The Institute of Electrical engineers has produced an informative guide based on the UK electrical law (17th edition) on this found here:
In essence you can not put any mains voltage equipment within 2m of the pool itself. For the same reason you can not bring a mains voltage appliances into the bath. When the pool equipment is attached to the pool itself in an underground box. You are running a 230v pump and control panel below the waterline with just a piece of plastic to separate it. One of the main serviceable items of a pool filtration system is the pump seal that wears out approximately every 3 years. Once this fails this unit will fill with water risking electrocution. One would hope that the system is protected by an RCD at the very least however these are by no means full proof either.
A conventional filtration system designed to both SPATA (swimming pool and allied trades association) and ISPE (Institute of swimming pool engineers) standards will suck out the water from one end of the pool, filter, clean, heat and treat then return to the opposite end of the pool. Logically this makes prefect sense as there are no dead spots or areas of stagnant water that bacteria and Algae can bread and no cold spots of water. This works just like a river bed! For this reason you will not find a Spata or ISPE member offering a pipeless filtration system as the standards can not be met as water is sucked and pushed from the same place. Whoever you choose to buy a pool from, whether its compass or otherwise, we always recommend they are a SPATA Member.
Going back to the filtration system itself, in a pipeless system due to the size if the filtration pod most utilise a cartridge or bag filter instead of a sand filter. Whilst most will perform adequately you should budget for the cost of filters that will need regularly changing and cleaning instead of the simple backwash process. Compass do offer a cartridge system but only coupled with a cyclone pre filter to reduce the cleaning frequency and prolong the life of the filter. While true that cartridge filters in general do filter down to a finer micron level the new supermircron filtration system with sand filter now filters down to the same fine level.
This fine level of filtration helps reduce the amount of chemicals used, but never eliminates them, for 2 reasons. 1, a filtration system can not kill bacteria transfer from one body to another through the water. 2, external factors effect the ph in your pool (rain and body contaminates, perspiration urine etc) if they ph is wrong it will corrode heat pumps and damage plastics, not to mention sting your eyes (think dove skin care) a cause that is often blamed on chlorine. Both of these need adjusting with a chemical. Sometime salt is one of these (sodium chloride) split into its elements electronically, that Compass offers.
Lets now address he pipes themselves that pipe free filtration retailers will whip up scare tactics around. Historically pool pipes were solid inflexible things delivered in 3 meter lengths. This made the susceptible to cracking with ground movement and a risk at every joint. Compass today have moved forward running flexible pipes in a single length to eliminate the risk of cracks in pipe work. These pipes are usually utilised by so called pipe free systems between the filter pod and the heat source (usually a heat pump)!
One key point a pipe free system will market is the reduced head loss. This is the friction generated by the pipe run. Whist this is true to a certain extent the design of the system can reduce this to a minimum. Firstly by using over sized pipes employed on all Compass Pools. Secondly, our optional variable speed pump will make a saving above and beyond those using a conventional pump by running the pump only at the necessary speed required at the time.
Running costs on a pipeless filtration system or any pool for that matter are an important consideration. Where the water is being sucked and blown from the same location, in order to help the poor natural circulation, often a larger sized pump is installed to try to throw the water futher. The flip side of this is obviously the running costs to do this. Pump sizes can be anywhere up to 1.5kw. Thats 15 100w light bulbs (no longer sold in the UK due to their energy demands)
Another scare tactic used by some competitors is the wasted water generated though backwashing for those on a water meter. The backwash process will generate approximately 500L of water. Looking at a water bill (jan 2014), most water authorities will charge in the region of £1.20 per m3 (1000L) thus a backwash will cost you about 60p. During the average swimming season you will do this every 2 weeks. Giving a total cost of £0.60 x 12 = £7.20. Compare this to the filter cost on a pipe free filtration system, normally replaced annually at a costs in excess of £40. While the sand in your filter will need changing every 5 yrs (£50), the optional glass system will last indefinitely.
Lighting in a pool adds hugely to the look of your new pool at night and careful consideration is taken to the placement of the lights themselves to ensure an even light within the water. They will normally be spaced evenly along the long side of the pool wall, on the side least visible. This is so that you don’t see the light source that can dazzle you and just see the glow of the pool at night. These are normally done in energy saving led pool light or a multicoloured variety. On a pipeless or single pod unit filtration you are limited to one light positioned where the filter unit is that has to be switched at that location.
Whist pipe free filtration systems are considerably cheaper to install we strongly believe the benefits of a full specification filtration system far out way the potential cost saving given the importance of clean, safe pool water, with a simple easy maintenance procedure. Furthermore there are no proprietary parts that could become obsolete or expensive to replace.
At the end of the say, the majority of these pools are sold by great sales men and marketers who are franchisees. They make great profit selling a very basic system for some healthy margins. But they are not engineers. Based on the evidence presented above we leave to you make you own conclusions.
We challenge anyone who is considering a pipe free filtration system to ask for a demo of the filter cleaning procedure on a pipe free filter then ask the same of us in our Gatwick showroom.