ECJ EUROPEAN Cleaning Journal

Does the sweeping challenge vary from season to season and country to country? Ann Laffeaty looks at seasonal sweeping and finds out how far environmental factors have an impact on machine choice.

Sweepers are required to remove anything and everything from a variety of locations, both indoors and out. But the type of debris that needs to be swept away can often be largely predicted. The environment in which the sweeper operates, the country it is in – even the season can help the operator to create a profile of the kind of debris that may need to be removed.

Hako’s municipal technology product manager Dr Olaf Heinemann confirms that seasonal changes alter the density, volume and type of debris that a sweeper may face.

“Substances such as dry sand and leaves usually need to be cleared up during the spring and summer while snow, wet leaves and mud are the items that tend to be removed in the autumn and winter,” he said. “This is why most outdoor machines are suction sweepers with water-based dust control systems.

They suck up dirt from the street like a vacuum and this is then collected in fitted containers.”

The grit and sand involved in springtime cleaning can sometimes exceed the weight limit of the average sweeper, he adds. “We find the main issue in spring relates to the weight of the collected debris whereas in autumn the challenge is more about volume.”

Roads and paths need to be regularly cleaned and maintained during the winter for safety reasons, according to Heinemann. “However, conditions in winter can be very unpredictable which makes multifunctional machines a good investment,” he adds.

Most single-purpose sweepers tend to be grounded during the winter when outdoor sweeping is often no longer required, he said. “However, the chassis of a multifunctional sweeper can easily be equipped with snow-clearing attachments to enable it to carry out light to medium winter service duties,” he adds. Such attachments include standard blade/spreaders, snow plough/spreader combinations and brine sprayers.

The type of dirt that needs to be cleaned away varies according to geographical location as well as the season, according to Heinemann.

“In northern countries the spring clean-up involves a great deal of heavy-duty sweeping of sand and grit left over from winter maintenance,” he said. “This is alongside all the partially decomposted leaves that have lingered behind from the previous autumn plus all sorts of other rubbish that may have piled up during the winter. In summer there will be more general dirt and dry sand to sweep away - mainly in light-duty form –while in autumn the sweeping-up of leaves becomes the next big challenge.

“The sweeping requirement varies in other geographical locations too: for example, in countries with no clear seasons the leaves tend to fall throughout the year and need to be cleaned up year-round whereas in coastal and desert areas the main challenge is the sand.”

High pressure water

In warmer areas it is common to use water at high pressure to supplement the sweeping effort, says Heinemann. “This helps to suppress the dust while also having a cooling effect compared with that of a standard blower,” he said.

The most challenging environments for sweepers are often historical districts, he believes. “These often combine uneven road surfaces with accessibility restrictions,” said Heinemann. “Special attention also needs to be paid to dust and noise emissions in these environments along with wheel loads. This means machines with suction systems that are pavement joint-friendly are especially welcome here.”

Despite the seasonal and regional differences, he claims there is little difference between the sweeping challenge in urban and rural environments. “However, you will find that the quantity of debris that is both lightweight and bulky is higher in larger municipalities due to more crowded events.”

Any type of challenge

Multifunctional machines can cope with any type of seasonal and environmental challenge according to Heinemann. “As well as carrying out seasonal sweeping and winter service tasks they can also be used for water applications such as sluicing, jetting and irrigating along with green area maintenance and transport tasks,” he said. Hako’s Citymaster and Multicar sweepers are both multifunctional models that offer these functions.

Weather conditions can have a significant impact on effective sweeping results according to IPC’s floorcare product manager Paolo Bassanini. “Every season presents a different challenge for the cleaning operator,” he said.

“The ideal sweeping environment is a clear road on a bright, sunny day. But in autumn a strong wind can drag heavy debris or wet leaves on to the street which means a powerful machine will be required to move it. And winter has its own challenges since snow, ice and frost can all impede the job itself.”

According to Bassanini, the season can have an impact on indoor sweeping as well as on outdoor tasks. “Sometimes the wind can carry in debris and leaves from outside,” he said. “The geographical location of a site also has an impact since some southern countries have the problem of sand gathering at the front of buildings. Northern countries, on the other hand, have to deal with snow and ice.” IPC offers a range of industrial sweepers including the 191 and 1404 multifunctional machines.

Wet conditions and high or low temperatures pose the biggest challenge for sweepers according to Nilfisk group product manager Thomas Tykskov.

“Our industrial sweepers are particularly well adapted for dust control and have a wet sweep by-pass that allows them to operate in wet conditions without dampening the filter,” he said. “This means they can be operated in all seasons. However, an outdoor sweeper solution will be required where the main task involves the removal of large items of debris or high quantities of leaves.”

High temperatures tend to be a challenge for engine-operated models while low temperature are an issue for battery-powered machines, says Tykskov. “A windy environment can also be a challenge where dust control is required,” he said. Nilfisk’s most recent sweeper launches include the SW5500 which comes in battery, LP-Gas and diesel versions.

Gravel and salt in the winter can be a big problem for sweepers says Kärcher’s product manager Marian Anton. “This type of debris can weigh a considerable amount so it makes sense to divide the volume between two hoppers when using a larger sweeper,” he said.

“Dust and dirt are the main issues in summer. Here an appropriate filter system will remove much of the dust and prevent it from returning into the environment. In particularly dry months it is a good idea to use additional dust reduction measures such as a water spray system for the side brushes. And larger industrial sweepers may be fitted with an air-conditioned cabin to protect the operator from the harsher effects of the sun.”

The large volume of leaves to be swept up in autumn means that the hopper needs to be emptied much more often, says Anton. A new container designed specifically for holding leaves is now available on Kärcher’s KM 105/100 R machine.

“In winter traditional sweepers are rarely used outside – at least if there is no snow,” he said. “But when this occurs our large industrial sweepers can be fitted with a heated cabin so the operator is protected from the cold.” Kärcher offers the KM 80 W for winter use which can sweep up snow using either the brush alone or with an optional snowplough.

Location effect

Anton agrees with other manufacturers that geographical location can have a major effect on the sweeping challenge. “For example, the quantity of dust experienced in hot Middle Eastern countries cannot be compared to the levels we see at European latitudes,” he said. “A well-functioning filter system is particularly important in the Middle East but on the other hand, those countries will have fewer problems with large volumes of leaves.”

Like Heinemann he feels the differences between rural and urban locations are minor. “A small village will have the same type of dirt as a large city, only in different dimensions,” he said. “Broken glass, cigarette ends, small stones, dust, pine needles, leaves – these can all be found in rural areas as well as in cities.”

He agrees with Tykskov that extreme temperatures can be a problem, with the cold being a particular issue. “Low temperatures will affect the service life of battery-powered sweepers while the issue of condensation when moving from a cold to a warm environment will have an impact on all the sweeper’s components,” he said.

However there are various ways in which a sweeper can be adapted to cope with seasonal and geographical challenges, according to Anton. “For example, solid rubber tyres will be useful on sharp-edged dirt such as glass or metal shavings,” he said. “A water spray system or side-brush covers will also help to reduce dust in the summer, while a leaf collection kit may be helpful in the autumn.

“And a rough dirt-catcher may be used if there is a particularly large amount of debris, particularly in winter. This can then be collected manually without forcing the operator to have to climb down from the sweeper.”

So, which season represents the biggest sweeping challenge? Opinion is divided. “Unpredictable weather conditions make winter the most challenging season in spite of ongoing discussions about climate change and rising temperatures,” says Hako’s Dr Olaf Heinemann.

Conversely, IPC’s Paolo Bassanini feels the dry, summer months present the biggest challenge. “The amount of dust is higher - and so is the variety of dust and debris that needs to be swept up,” he said.

But autumn is the biggest problem for Kärcher’s Marian Anton. “Large quantities of dust and gravel are standard tasks for the sweeper and can be achieved without any great problems, but in the autumn you have to cope with a large volume of leaves,” he said. “But whatever the seasonal challenges there are attachments and accessories available to tackle them.”