A recommended option if we are looking for maximum savings, but one that has its disadvantages. Choosing the right temperature when turning on the washing machine is a key aspect that will influence how clean the laundry will be, but also the amount of energy we will use during the process.
In fact, lowering the temperature and doing what is known as a “cold wash” is one of the factors that will save the most, but it also leaves important questions unanswered regarding the quality of the wash. Is it advisable to use these low-temperature programs? What are their advantages and disadvantages? Let’s take a look.
Cold washing, the option that saves the most energy
To begin with, we have to define what this “cold wash” is, and basically it consists of selecting the operating mode on the washing machine in which the machine heats the water less. In general, and depending on the model, this means that a temperature of less than 30-40 ºC is chosen.
These programs, with their reduced temperatures, have traditionally been reserved for delicate garments that shrink or are damaged by heat, but they also save energy, and it is advisable to use them when the laundry is not apparently very dirty. How much can we really save?
According to the OCU, by washing at 30ºC or less it is possible to save up to 60% of energy in the process, figures that coincide with those of Repsol, where they explain that we will spend “double” when washing at high temperatures compared to a cold wash, since the appliance consumes 85% of the energy in heating the water.
From Naturgy they give more specific figures highlighting that while short cycles and cold water consume approximately between 0.5 and 1.5 kWh, a hot wash cycle can use up to 3 kWh. This means that with an average price of 0.20 euros per kWh, we can save up to 0.50 euros on each wash.
For all these reasons, a cold wash will always be more economical than a hot one, although logically we will not have the same effectiveness in cleaning complicated garments or, of course, the same hygiene and disinfection capacity.
Cold washing and disinfection of clothes
In fact, the latter is the main problem with cold washing and there are studies that indicate that washing at 40ºC only eliminates 15% of the bacteria from the clothes, leaving behind a significant amount of harmful microorganisms, including dust mites and E. coli, which require higher temperatures to be effectively combated.
However, there are additional factors that allow washing at less than 40ºC to improve disinfection, such as the type, quantity and quality of the detergent we use or the advanced functions of the washing machine, if our model has them.
For example, there are models with disinfection technologies that use the injection of oxygen bubbles that eliminate more impurities without having to raise the temperature and thus save energy. There are also machines with higher spin speeds above the now classic 1,000-1,200 rpm, which help to improve the removal of dirt and ensure that a higher percentage of microorganisms are left out of the garments.
So, can I always resort to using cold wash to save money? Well, if what we are looking for is maximum savings, the clothes are not very dirty to the naked eye and we are not faced with the need to disinfect, the general answer is yes. But if our objective is maximum hygiene, for example to prevent the spread of flu at home, it is advisable to use higher temperatures.
What is the recommended temperature for maximum disinfection? Manufacturers such as AEG, Haier and Siemens and detergent companies such as Sanytol agree on a minimum temperature of 60°C for effective disinfection, although in specific cases, if your washing machine allows it, you can even go above this figure with fabrics that can withstand it.
