Despite the massive strides taken by the laundry sector worldwide, there are still major opportunities for reducing the carbon footprint of individual laundries which, when taken together, should make a significant impact on the national carbon footprint. Several of these opportunities require little, if any, investment but they do need some management thought and time. They also produce useful financial savings or improvements in productivity, so this month we take a look at what they are, how to implement them and the benefits which you can expect.

Each country’s actions to fight climate change will span several years, so it is also important to get your future strategy right for equipment updating and maintenance and for the design of greenfield laundry installations. This includes decisions on the central boiler, and on the best choice of energy source, both for the boiler (if you decide that you really need one) and for modern advances in energy sources at the point of use. Making your full contribution to fighting climate change is not a quick sprint – it is a marathon, but you need to do the groundwork now!

Choice of fabric for rental textiles

Most rental fabrics are made from either polyester or cotton or a blend of both. The energy expended in the manufacture of polyester is estimated to be twice that of cotton per kg, according to a recent BBC investigation1. The higher the percentage of polyester in a rental fabric, the lower the moisture retention and so the lower the drying energy required. However, the customer often perceives cotton as the more user-friendly fibre, because of its breathability and absorption properties which improves wearer and sleeper comfort and towel performance in drying.

Combining these factors together in the mainstream, high volume market for good quality rental products has led many launderers to have the majority of their circulating stocks of a cotton rich blend for flatwork. With towelling, while the majority of towelling remains 100% cotton, many launderers are looking at cotton/polyester with a small percentage of polyester staple spun into the ground-weave to improve tear resistance and compensate for any progressive loss in strength during multiple laundering.

These strategies combine the low carbon footprint of cotton manufacture with the reduction in drying energy and the improvement in textile life offered by the smaller polyester content, without compromising unduly the perceived quality of the product.


The former British Launderers Research Association (BLRA) did valuable work pre-1950 on optimisation of wash dips to give maximum soil removal in the minimum time. The best dips to achieve this varied only slightly with machine capacity, but for a 100kg washer extractor they called for a dip of around 75mm. Many launderers have since found that they could reduce their wash dips down to the BLRA recommended levels, which gave them better wash performance, quicker fill times and reduced heating times. This made a useful contribution to the carbon footprint of the washhouse. Those who extended dip tuning to the rinses, supported by the use of souring, have made an even greater impact on the cost of their water and effluent charges (with further small reductions in carbon footprint).

An even greater breakthrough has been made with the successful introduction of low temperature washing; it is now possible to get most classifications clean and stain-free at 40C. This is achieved by much smarter wash chemistry, using targeted emulsifiers and detergent and chemical technology where appropriate. This appears set to make an even greater reduction in the carbon footprint than tuning of the dips, but both are vital to address climate change.

Stain removal

Fifty years ago, sodium hypochlorite (chlorine bleach) dominated laundry stain removal, because of its oxidising power. Unfortunately, this was combined with its rotting effect on cotton fibres, which increased dramatically if it ever got into the hot wash. Fortunately ,there are modern replacements which largely overcome these problems, based for example on hydrogen peroxide, sodium percarbonate and peracetic acid. These perform splendidly, provided they are a part of a professionally set up and well-managed wash chemical system. This is key to increasing textile life, whilst delivering consisting high-quality linen to the customer.

Getting stain removal right is also the key to managing rewash and the associated carbon cost of double washing. Operating with a main wash at or below 40C should mean an end to setting of protein stains and unnecessarily harsh bleaching of these. If these can be correctly softened so that they all come away in the hot wash, then all the modern stain removing bleach has to do is de-colour the vegetable dye stains from tea, coffee, red wine, beetroot and so on, which is relatively simple.


Removal of moisture from the washed textiles represents a major (and often missed) opportunity in great many laundries. It is fifteen times more expensive in energy terms to remove moisture in tumble drying than in mechanical hydro-extraction. The final spin in the washer extractor should be at the maximum speed available, provided that the classification being spun does not acquire irremovable creases. The duration of the spin should be long enough that addition of another 30 sec does not remove any more moisture.

On the tunnel washer line set up for flatwork, dewatering is probably achieved in a membrane press. This will almost certainly come with a pressure gauge which shows the pressure on the ram (and therefore on the textiles themselves).. Launderers should seek to maximise the time and pressure of their textiles under the membrane press that is suitable for the construction and type of textile. This will help significantly to reduce the drying time in the tumbler and improve productivity on the ironer line.

A parallel benefit from press tuning is a reduction in dissolved impurities in any unremoved rinse water being carried forward to the ironer and reducing the life of ironer clothing or causing progressive greying or browning of the textiles.


Partial drying of flatwork in the tumbler, in order to get the ironer to run faster is false economy, because it is accompanied by an unnecessary increase in the energy demand of the inherently less efficient tumble dryer, compared with the much more efficient ironer. Excessive conditioning for flatwork is also a waste of tumbler time, especially when hotels are demanding ever heavier towels and robes.

If the tumble dryers cannot cope with the workload, then detailed work should be undertaken to optimise the moisture retention of the work leaving the washer lines. This should pay immediate returns in reduced dryer times and the elimination of conditioning. If this is not sufficient to solve the problem, then see the next section on reducing dryer times further.

Tumble drying

It is vital, for energy economy and productivity, to manage the tumble dryers efficiently, but this is not easy. Washing and drying full loads is essential, especially if the dryers are controlled by conventional timers, but some loads get are over-dried and others come out still damp. Tuning the hydro-extraction to consistently minimise moisture retention helps, but more is needed. Automatic cycle terminators offer a solution in the latest dryers, because these continuously sense the moisture in the drying textiles and terminate the cycle at the correct moisture level. This minimises the carbon footprint of the dryers very effectively; it also eliminates damp loads and avoids the discolouration associated with over-dried loads.


If the ironer is to maintain a reasonable output, then in order to enable it to iron flatwork straight from the washer extractor, the final spin must first be optimised. The ironer tuning must then be checked, to ensure no cold spots, good vacuum all the way across the beds, perfect roll-to-bed contact (by matching the diameters of the clothed rolls to that of the beds) and so on. The textiles need to be fed so that they are virtually edge to edge going into the first nip and if this needs some intermediate preparation then this is better than conditioning or buying a further ironer.

Textile life

Rental operators, hotel managers and hospital launderers who institute monitoring of textile life in circulating stocks appear anecdotally to be getting between 90 and 120 wash and use cycles for their linen. One hospital launderer, with whom Laundry Technology Centre has worked in the past, reported increasing average life from 120 cycles to 175 cycles. This took them twelve months and some imaginative persistence, but it reduced their textile purchase costs by 30% per annum.

Future equipment strategy

In order to minimise the carbon footprint and plan for a future when energy costs will be higher and energy itself might be scarcer, it might be wise to plan for distributed heating for the dryers, ironers, garment finishers and so on. The energy loss up the flue of a central boiler represents around 20% of the fuel purchased, whereas in a direct gas fired tumbler, all of the products of combustion go into the drying airstream.

The tunnel washer is designed to be inherently more economical in its wash energy demand when compared with a washer extractor, so it makes sense to make the latter an exceptional purchase. There are tunnel washers now available to cope with the modest demands of a small laundry and they are now an affordable option for most units.

Tumble dryers should always be ordered with the manufacturer’s option of automatic cycle terminators. These will repay the additional cost in energy saved, often within the first twelve months; they should also give significant productivity benefits and associated quality improvements.


It may come as a surprise that the main points in this article require little or no investment! That is intentional, because there is no point in committing often substantial investment in energy and water recycling before the free opportunities have been realised. When the fine tuning described in this month’s article has been completed (which might be a 12-month job for the production and engineering teams) then is the time to consider investment in recycling, but that is for a future article from LCN.