How to Reduce Pure Water Consumption When Cleaning Windows

The cost of a water-fed pole job does not depend solely on the operator’s time. Every litre produced, transported and used affects the working day’s autonomy, consumable wear and service profitability. Reducing pure water consumption when cleaning windows does not mean working with the lowest possible flow without consideration; it means using the water required, where it is needed, with a correctly adjusted system.

On façades, communal buildings, shop fronts and recurring maintenance jobs, genuine savings begin before the pole valve is opened. The quality of the incoming water, the condition of the filtration system, brushing technique and route planning all determine how much water is used and how much is wasted. If the finish suffers, marks appear or additional cleaning takes longer, the supposed saving is no longer a saving.

Where water is lost in a pure water system

It is useful to distinguish between two different types of consumption. The first is the water that reaches the brush and is used directly on the glass. The second is the water used during production, particularly in systems that incorporate reverse osmosis and generate a reject-water flow. Both can be optimised, but they require different measures.

During cleaning, the most common excesses are maintaining a high flow rate on every type of surface, rinsing for longer than necessary or allowing water to run while repositioning the pole. During production, the problem is usually caused by working with exhausted filters, failing to monitor the quality of the incoming water or choosing equipment that does not match the actual workload.

The professional objective is not to find the lowest possible flow rate. It is to find a stable flow that keeps the bristles lubricated, carries away dirt and allows a complete rinse without using more water than necessary. This balance varies according to the height, level of dirt, brush type, available pressure and conductivity of the treated water.

How to reduce pure water consumption without compromising quality

Adjust the flow rate according to the stage of the job

Dirt stuck to frames, seals and sills requires more water than glass with a light layer of dust. Using the same flow rate all the time means compensating with longer brushing or causing unnecessary consumption during routine maintenance.

On a first pass over heavily soiled surfaces, increasing the flow rate may be appropriate to remove particles and prevent the brush from dragging them across the glass. Afterwards, when working on the glass and carrying out the final rinse, a moderate, continuous flow generally provides a more controlled result. Adjusting the flow at the handle or using a flow-control system makes it easy to change the flow without lowering the pole or interrupting the working rhythm.

Turning off the water during short movements also has an impact. It may seem like a minor action, but on routes involving dozens of panes, frequent repositioning or difficult access, it prevents litres of water being lost without contributing to the cleaning.

Use the right brush for each surface

The brush is not an interchangeable accessory. A model that is too soft for persistent dirt may require repeated passes and a longer rinse. One that is excessively aggressive for routine maintenance may retain more debris or make it harder to work smoothly on certain types of glass and frames.

The choice should take account of the type of dirt, service frequency and surface finish. Bristles that retain their shape, well-positioned jets and a well-balanced brush block help direct water towards the working area. This avoids wetting areas unnecessarily and improves dirt removal with fewer passes.

The cleanliness of the brush itself also matters. If it collects dust, building debris or particles from the frame, it will transfer dirt to the glass and make another rinse necessary. Checking it at the start of the day is a simple task that protects both the finish and water consumption.

Maintain the correct brushing and rinsing technique

Pure water removes the need to dry the glass with a window-cleaning squeegee when using a water-fed pole on external work, but it does not remove the need for a correct sequence. Brushing from the top, working in an orderly way and rinsing from top to bottom reduces the risk of dirt running back onto areas that have already been cleaned.

Frames require particular attention. If they are brushed after the glass or rinsed in a disorganised manner, they can release debris onto the glass and make the process have to be repeated. With heavy soiling, it is preferable to carry out an initial, dedicated frame clean and leave the final glass finish until the last stage.

Working distance also has an influence. A pole with the correct reach that is rigid and well balanced allows the brush to be positioned accurately. When the operator has to force their posture or works with the pole flexed excessively, they lose control over pressure and jet direction. The result is usually more water, more time and less consistent rinsing.

Monitor water quality and consumable condition

The efficiency of a system is not measured solely by the litres leaving the tank. It is measured by the litres that produce a spotless result. If the resin is exhausted or the system supplies water with a total dissolved solids reading that is too high for a residue-free finish, the problem cannot be solved by increasing the rinse. On the contrary, this increases consumption and may make it necessary to repeat the work.

A TDS meter allows the performance of the treatment system to be checked objectively. Recording inlet and outlet readings helps anticipate consumable changes and identify variations in mains water quality. Not all areas have the same water hardness, and not every working day requires the same level of production.

Pre-filters and membranes should be maintained according to usage and the equipment manufacturer’s instructions. A saturated pre-filter can affect overall performance, while resin forced to correct poorly pre-treated water will be exhausted sooner. Replacing a consumable at the right time is usually more cost-effective than working inefficiently, using excess water and carrying out additional cleaning.

Choose the system according to the actual workload

For occasional jobs or routes with limited consumption, a deionisation system can be practical because of its simplicity and quick set-up. However, when daily volume increases or the incoming water has a high mineral content, resin management can become a significant operating cost.

Systems with reverse osmosis reduce this load before the final polishing stage, which can extend resin life in certain situations. In return, factors such as production flow rate, reject water, available pressure and the time required to fill tanks must be considered. There is no universal configuration: the right option depends on daily litres, the logistics of each route and local water conditions.

Before buying or expanding a system, calculate how many hours are spent working with a water-fed pole, how much autonomy is required and where water can be produced or loaded. An oversized tank adds weight and transport requirements; an undersized one forces top-ups that disrupt planning. An efficient configuration is one that keeps the service running without carrying unnecessary capacity.

Reduce losses in hoses, connections and transport

Small leaks have an accumulated cost, particularly when working for many hours. Check connectors, quick-release couplings, hoses and valves before starting the route. A leaking connection does not just waste water: it can reduce pressure at the brush, cause stoppages and damage the working environment.

Use hose lengths suited to the access requirements. Carrying more metres than necessary increases the volume of water left in the line at the end, makes movement more difficult and increases the risk of snagging. On long runs, the hose should be properly guided to prevent kinks and avoid forcing the operator to pull it with the pole.

Planning the working day also reduces indirect consumption. Grouping jobs by area, producing the required volume and avoiding journeys with unnecessarily full tanks improves the management of water, fuel and physical effort. For recurring work, recording approximate consumption per building makes it much easier to plan the right load.

Measure consumption to make useful decisions

Without a baseline, it is difficult to know whether an improvement is working. Over several working days, record the litres loaded, effective hours of water-fed pole use, type of service and any additional-cleaning issues. There is no need to turn every job into a complex report: a basic record sheet is enough to identify deviations.

If consumption per hour increases without any change in dirt levels or surface area, first check the flow rate, brush and leaks. If the finish deteriorates, check the outlet water quality before blaming the technique. This data helps you decide when to replace consumables, adjust a system configuration or add an accessory that makes system control easier.

At Limpieza Cristales Unger, as Unger’s authorised technical service centre in Spain, the value of technical advice lies precisely in adjusting tools, poles, brushes and water treatment to the way each professional actually works. Saving pure water should improve productivity and preserve a clean finish, not compromise it. When the system is correctly sized and maintained, every litre used has a specific role in the final result.