Hot, warm or cold wash: How to make the right choice for your laundry

May 21, 2018

It’s no secret that saving money on utility costs is a priority for most laundry operators. Especially when you consider that operating a typical on-premise laundry consumes more than one-third of all the water, electricity and gas consumption of the premises.

Also, the need to have clean, disinfected linens is paramount to the health of your guests and residents. In fact, the primary goal of any laundry operation is generally disinfection and wash quality.

Therefore, it is vitally important to ensure that your laundry is both efficient, saving you money on utilities, and effective, ensuring a deep clean every time.

Whether you wash in hot, warm or cold water will significantly affect your results in these areas. However, what is best for one laundry may not be best for another.

Do you know what temperature is best for your situation? Read the following guide to help you make an informed choice and secure maximum efficiency and effectiveness for your commercial laundry.

Hot washing (65 degrees or more)

Washing in hot water at 65°C for 10 minutes or 71°C for 3 minutes results in thermal disinfection, according to AS/NZS4146:2000.

The primary benefit of hot washing is the certainty that disinfection will occur once the thermal disinfection requirements have been met. This also generally results in superior wash quality compared to the lower temperatures, provided that all other variables remain the same.

The drawback of hot washing is that it typically results in longer cycle times due to the additional heating time. This may increase electricity and water consumption, compared to washing at lower temperatures. There is also a risk of damage to heat-sensitive fabrics if they are washed in a hot wash.

Warm washing (40 degrees)

Washing in warm water and using a correct combination of specialised chemicals will result in chemical disinfection at the same level of effectiveness as thermal disinfection.

The benefit of warm washing is that it requires shorter wash cycles than a hot wash, as little to no heating is required. There is also no need to maintain or service an engineering solution such as an ozone unit. Both of these factors mean that the costs of running your laundry may be less if washing in warm water as opposed to hot.

The drawback of washing in warm water is that the process of injecting hot and cold water during the fill steps (fill modulation) can add extra time to the wash cycle, compared to a cold fill. Also, it may not be as effective as hot water in removing heavy soiling. If heavy soiling is not removed in the warm wash cycle, the linens will need to be washed again on a longer, hotter cycle. Therefore, the cost benefits of a warm water wash will not be achieved if soiling is heavy and the wash cycle is long.

Cold washing (20 degrees)

A cold water wash, in combination with an ozone system and particular chemicals correctly mixed and applied, will deliver chemical disinfection to the same level as thermal disinfection.

The cold water wash is a popular option for those who have light to medium soiling and are interested in minimising utility costs. It is usually the shortest wash cycle, as the machine fills directly from the cold valves with no fill modulation or heating required, depending on the wash cycle classification. This method yields the greatest savings to water, electricity and gas consumption, and also leaves the smallest environmental footprint.

A cold wash is not without its limitations, however. Because the cold wash may not yield the best wash quality, particularly when heavy soiling is involved, the effectiveness of the laundry is heavily reliant on staff to correctly sort the linens and use the correct wash cycle to achieve consistent results.

Also, some ozone units use a Venturi system, which slow down fill times. Ozone units are an additional piece of equipment that take up space and require periodic maintenance and testing. This, along with the slower fill times, can result in unexpected costs to productivity and profit.

Your commercial laundry experts

The Aqualogic team are experts in the set up and maintenance of commercial laundries, and we can help you to determine what options are best for you. You can rely on us to get the best wash results in your laundry and ensure that your commercial washing machines perform at their best every time. Contact us today to discuss your specific needs: contact us online or call 1300 222 119.