Article by Maria Eva Virga
A heat pump is a machine that is able to transfer energy from external sources (air, water, soil) to heating, air conditioning and hot water systems. In air conditioning systems, units that heat and cool the air are commonly known as “air–to–air heat pumps”. While units that only offer the cooling function are called “air conditioners”.
Air-to-air heat pumps operate with a ‘split’ system. In this technology, one or more indoor units are connected to an outdoor unit. The system, which contains refrigerant, transfers heat from one part of the equipment to the other. During cooling, the air-to-air heat pump extracts heat from the air inside the house and releases it outside. It operates similarly to a refrigerator. During heating, it extracts heat from the air outside. And it releases it inside the house via the indoor units.
Heat pumps can be adapted to numerous fields of application. This by virtue of the wide spectrum of power and temperatures that can be achieved. And thanks to the types of fluids they contain. There is also the possibility of supplying them with renewable or waste energy sources.
Since the early 2000s, heat pump technology has also been incorporated in tumble dryers. In fact, a heat pump tumble dryer works like an air conditioner set in heating mode. Thanks to the presence of an internal motor and a cooling circuit, the tumble dryer generates heat. And the appliance transfers it into the drum to dry the laundry.
How a heat pump tumble dryer works
A heat pump tumble dryer dries clothes using recycled hot air. And not a heating element, as is the case with condenser tumble dryers. After passing through the drum, the air reaches the evaporator. This removes the moisture, which is then collected in a tank. The remaining air is reheated to continue drying the laundry.
This tumble dryers use a technology similar to modern air conditioners, which heats the air inside the drum efficiently. This ensures gentle drying of fabrics and reduced energy consumption. The heat pump produces hot air that liquefies the cooling agent, in order to generate extra heat without using additional energy. The air pumped through the evaporator removes moisture, after which the remaining hot air is stored and reused for the next cycle.
Energy class A heat pump tumble dryers have become the market standard, not least because they offer significant savings in electricity consumption (up to 50% less) compared to condensing models and are therefore ideal for frequent use. Although some heat pump tumble dryers are equipped with fast drying programmes, the cycles are generally longer than those of condensing tumble dryers. However, energy savings and better protection of fabrics compensate for this factor.
Newer heat pump dryer models are also equipped with sensors and use artificial intelligence to recognise the load and automatically adjust the temperature and drying time. In addition, most of the latest heat pump tumble dryers are ‘smart’, meaning they allow start-up, monitoring and receiving end-of-cycle notifications, as well as remote maintenance advice, via App.
The mechanism in washer-dryers
In washer-dryers, the drying process is the same, but a washer-dryer is obviously a single appliance that has to handle two different tasks, i.e. washing and drying, with the advantage of not having to move the garments to another appliance. First there is the washing phase, in which water and detergent are evenly distributed among the fabrics, then comes the drying phase.
