Clothes dryer

A dryer is a home appliance, which is used to machine drying wet textiles under the supply of warm air in a short time. Standard units have the shape and size of washing machines and are often simply called dryer. Devices that combine the functions of washing and drying in one unit, hot washer dryer.

Tumble-drier are in Switzerland after the English expression tumble dryer called tumbler. In Hamburg, the term is used porpoise, the Low German equivalent of the English word " tumbler ".

• 2.4.1 dryer with heat pump
• 2.4.2 dryer with heat from the house heating

• 4.1 dryer balls

History

The first European clothes dryer was developed in 1958 by Miele. To date, only the design and other features have changed, the basic principle has remained unchanged. Early as 1800, the first hand-operated clothes dryer was invented by M. Pochon from France. The first electric clothes dryer came in the early 20th century on the market. In the 1940s, the industrial designer Brooks Stevens designed the first dryer with a glass window.

Types of dryers

Physics of drying

To dry laundry, the water should first be removed mechanically. A spin dryer is reduced, depending on the number of revolutions and drum size, the amount of water to 80 % to 50% water content, based on the dry weight of the laundry. Higher degrees of drying are difficult to achieve in this way, as the water is bound to the capillary fibers.

The subsequent drying on evaporation of water is energy intensive. The evaporation of 1 kg of water at an initial temperature of 25 ° C requires 2600 kJ or 0.73 kWh. Drying 1 kg of washing with a residual moisture content of 60% requires approximately 0.5 kWh. A heat recovery from the water vapor is technically complex and hardly saves energy.

To 6 kg Drying clothes a wash cycle, about 3 kWh of energy must be used. At a price of 0.30 € / kWh drying of 6 kg wet wash costs about € 0.90.

Drum dryer

The clothes to be dried is in a horizontal rotating drum. Thus it is constantly circulated and achieved a large effective surface area of the laundry.

Heated air flows along the drum axis of rotation through the wet laundry in the door. Here, the dry and hot air is able to absorb the moisture of the laundry to the saturation limit.

After the moist air has passed a lint filter, it is - dried by condensation or blown into the open - depending on the model.

Unlike washers dryers often have no clear window in the front door. There are also devices with transparent hatch and even with indoor lighting, so the laundry can be observed during drying.

Vented tumble dryer

A vented tumble dryer is the moist air from, for example, via an exhaust hose or a fixed line. To avoid damp rooms, the exhaust should always be conducted outdoors. In addition to the moisture even fine lint will be played. So that the back pressure is not increased unnecessarily, the exhaust duct has a diameter of 10 cm, the line length is typically less than 3 meters. This condensed water does not remain in the exhaust line, a slight gradient of about 2 ° is recommended towards the outlet. When in the room or in adjacent rooms furnaces (furnaces, boilers, gas boilers ) are, can the low vacuum, the produced the clothes dryer in the room, cause the fireplaces do not pull, so danger of poisoning by exhaust gases. It must then be (for example, through a gap wide open window) ensures that fresh air can flow from the outside, so that in space there is no vacuum. Also, the dryer works better then. Little is known that even a slight vacuum in buildings can suck the radioactive gas radon from the soil, leading to increased radiation exposure.

Kondensatorbox

In order to operate vented tumble dryer in enclosed spaces, various external capacitor boxes are offered. These are connected to the exhaust hose and to cool the air and collect the condensed water. This can function efficiently only with a cooling system when the unit is not placed in a cool cellar. Some models use for water or cold packs that need to be frozen in the fridge before. Thus, unnecessary energy-saving considerations, such boxes just plug it in to keep the heat from exhaust air in the room in winter.

Condensation dryer

When condensation dryers, the air is inside the dryer in a largely closed circuit. The first cool circulating air is heated, whereby the relative humidity drops ( warm air can hold more moisture than cold ). This warm and dry air is blown through the drum in a recirculating, wet washing and, due to its moisture evaporation on. The arranged under the drum capacitor (actually heat exchanger) has the task to remove the moisture from the air circulation equipment. For this, the warm moist air is cooled. A paired with the drum motor fan delivers cool ambient air across and spatially separated by metallic plates through the condenser.

In this case, in the capacitor of the temperature-dependent dew point is not reached, and excess moisture condenses out as the liquid water, which collects first in a subsequent tank. The cooled circulating air is then warmed again, the cycle is closed. The heated when flowing through the condenser ambient air is discharged into the ambient space; it can not be used for re-heating due to the lower temperature level. This " air-cooled " dryer work better, the cooler the main room.

The condensed water is pumped by a cyclically operating pump in a mounted generally adjacent to the control panel container which is to be emptied regularly. Optionally, a condensation dryer are also connected by a hose to an existing drainage. To a separable hose connection is usually provided on the back of the device.

In the condenser, fine lint are deposited; it must be cleaned regularly. Furthermore, such devices require a little more energy than air dryer (~ 10%); unlike the vented tumble dryer, the energy is not discharged into the atmosphere, but released as heat to the main room. This is in a residential installation in winter an advantage as heating energy is saved, in the summer, however, more of an inconvenience.

They are of an output ( wall outlet or similar) regardless of the exhaust hose. In the acquisition, they are more expensive than a vented dryer.

The measured energy demand is for example a Siemens S46.51 equipped with 6 T -shirts and 4 pants, cupboard dry at 2.4 kWh.

Market conventional devices are presently achieving only the energy efficiency class B. For vented tumble dryer and condenser dryer differently rigorous assessment criteria apply; so it happens that a condensation dryer energy efficiency class B requires more power for the same amount of laundry as a vented dryer energy efficiency class C.

Dryer with heat pump

There are condensation dryers operate on the principle of the heat pump. Its market share in 2011 was 22 per cent (2010: 14 percent). The hot part of the heat pump heats the incoming air, the cold part of the moisture condenses the exhaust air. These devices consume much less energy. Compared with conventional devices, energy efficiency class B has a clothes dryer with heat pump technology more than 50 % energy savings. Modern condenser dryer with heat pump achieve energy efficiency class A, among which are quite economical models, giving details of A-50 % (which would correspond to an extended European norm of A ), or even A-60 %.

In the acquisition, they are usually a bit more expensive, relative to the total cost ( including electricity ) but significantly cheaper. Stiftung Warentest calculated in their test at 10 years of use, total cost of good 860-1150 Euros, for conventional dryer compared with around 1030-1430 Euro.

The drying time is longer than that of the devices with heating element usually a bulging drum cabinet is often completed after more than two hours.

Dryer with heat from the house heating

Here the dryer to be supplied by connecting to the heating of the central heating via a heat exchanger with the required hot air. At the current retrofit solution is a fully enclosed radiator or heat exchanger, which is connected via corrugated pipes in the air of the dryer. Instead of the built- in dryer, electric heating of the hot water flow rate of the connected hot water heater is turned on and off. Whether this type of environmentally friendly or energy-efficient than the direct electric heating depends on how environmentally friendly and economically is the connected central heating. Theoretical savings of 2/3 as compared to conventional technique are possible. An operation with solar-generated heat is also possible and reduces operating costs. A launch as an integrated unit was planned for spring 2009.

Gas-fired dryer

In Europe, relatively rare dryers are heated with gas. The purchase prices are generally higher, the energy efficiency is better than in electric devices. Your purchase is subsidized occasionally by gas suppliers. In Anglo-American countries, this version is more common.

Washer dryer

A washer dryer is the combination of a condensation dryer with a fully automatic washing machine in one device.

Because the laundry more space in the drum during the drying as needed when washing, just half a wash load can usually be dried; you have to remove a portion of the washing and optionally drying later in a second drying cycle, therefore, after the washing process. Therefore, such devices are often sufficient only in one-to two -person households; in larger households blocked every wash load the device for so long that the wash volume can not be overcome.

There are devices available which can dry a laundry load in a single pass. Often, however, this works only when the amounts, which greatly increases power and water consumption. The devices require inherently a very long time for a complete passage, typically five to six hours at five kg of dry linen. However, the device saves space, since instead of two devices, only one is needed.

Washer dryers are usually built without the fluff and get cold fresh water for condensation of moist warm air recirculation; they consume therefore also suitable for drying water. Compared to two individual units therefore result in higher operating costs. Since 2010, however, there are washer dryer on the market, which do not require the increased water consumption during drying, but as heat pump dryer to dry the laundry. The devices are similar in structure more of the washing machine and are therefore available as a front or top loader.

Unit malfunctions often fall both functions simultaneously.

Drying cabinet

An alternative to the drum dryer is the drying oven with a built-in fan, which works according to the exhaust air dryer principle. Here, the laundry is hung in a chamber that is blown into the cold or heated air. In cold air operation of the drying cabinet is very economical, on the other hand consumption of hot air mode (with heating ) is significantly more power than comparable drum dryer. There are also drying ovens, which operate on the condenser principle.

Room air dryer

With the indoor air dryer, the laundry is dried mainly in Switzerland. Mounted on the wall, the unit blows a stream of dry air in the suspended on linen laundry. The drying device works according to the principle of the heat pump. It absorbs the moist air, the moisture contained therein is condensed on the cold surface of the heat exchanger. The energy required for operation is used to heat the cooled air. The condensate is collected or derived directly to the sewer. The room air dryer shuts off automatically when the moisture sensor indicates that the moisture content of the air corresponding to the desired level. Since neither mechanical forces nor act to heat the wash, all fabrics can be dried. Even sports equipment such as hockey equipment, or tents, can be dried in this way. A positive side effect is the simultaneous dehumidification of buildings. Modern air dryers also have about an electronic control. This allows different modes to use as a room air dehumidifier the air - dryer ( for example, in the new building).

Because contrary to other drying methods, the laundry is not dried with heat, air - dryer are highly energy efficient. In order to compare the different providers, their own test methods have been developed. The Association for the Advancement of room air dryer VRWT features behalf of the Federal Office for Energy in Switzerland, the energy-efficient appliances with the label " Qualidryer ". Buying a room air dryer will be rewarded in Switzerland by various energy suppliers with direct remuneration.

Alternatives to Dryer

In households with small garden or balcony is often a line drying in the open air (especially in changing weather conditions, if necessary, under a canopy ) possible, so much energy can be saved. Quick dries the laundry in direct sunlight and / or wind. The UV rays in the sunlight disinfect the laundry (if after washing at all microorganisms on the laundering ) and whiten them (which is desirable in white linen; colored in wash it may be undesirable ). Line drying is considered to wash gently; the Flusenstaub in a tumble dryer shows that parts of fibers in the dryer " cancel ". Linen drying in a roof storage / attic uses there often present relatively warm and dry air. Another possibility is to line the drying in a special drying chamber ( for example, former laundry ) with a high-performance electric blower which discharges the moist air to the outside. Assuming the presence of a suitable space, the investment and operating costs are low.

However, the line drying is not always possible: In poorly ventilated attics or basements just such wash the laundry dries in the fall and winter often only after several days or even weeks; any spaces and masonry damaged by moisture. Not useful is also the laundry hanging in heated living spaces, if they contain low air exchange rates; the moisture must then be dissipated through increased very extensive ventilation, which may go even lost more heating energy than an electric dryer would consume. While blowing a vented tumble dryer in room air and heating energy contained into the open, if it is placed in a heated room; but he did not moisturized after all the installation room. However, there are also living spaces in which the air change rate is already high, in which case also hanging the laundry can contribute to increased humidity. In this case the Wcheaufhgen can even save energy because you do eventually saves a humidifier.

Some particularly tightly woven or thick pieces of laundry (eg, extra thick towels or bath mat ) you get completely dry in the open only in particularly favorable conditions.

The demonstrably erroneous idea houses were "breathing walls ", is due to a measurement error in the 19th century. Moisture can not diffuse through the outer wall to the outside; proper ventilation is important. However, windows can be quite permeable to humidity.

Budgetary practice and operation

Not all textiles tolerate drying in the tumble dryer. Synthetic, Wool and silk can be damaged; vegetable fibers may shrink. In particular, knitwear ( ie especially underwear) tend to shrink. Drum dryer offer at least a normal program and a gentle program ( with reduced temperature ), further comprising at least one timing, nowadays usually a control with humidity sensor, the program reaches the adjusted degree of drying (eg lack moist - iron dry - cupboard dry - extra dry) ended. About drying should be avoided as just knits otherwise reinforced shrink and severely creases the laundry.

In the older literature is recommended underwear, to be dried by machine, a number to buy larger than normal. Safe, but it is only those underwear to buy, which is explicitly declared as suitable for tumble drying ( care label ).

In the lint filter part substantial amounts of lint accumulate. The wire must be cleaned after each use; Washer dryer instead have a " fluff - Rinse " program. However, the fluff arise only 10% using machine drying; the remaining 90% are already rubbed off by wearing and washing.

The more thorough the wash was spun, the faster and more energy efficient proceeds the subsequent drying. Additional spin consumes much less energy than achieving the same degree of drying in the dryer.

Laundry from the dryer is very soft and fluffy even without fabric softener, in some textiles even unnecessary ironing. Pet owners appreciate just to exhaust air dryers that animal hair is pretty well removed.

Unlike drum dryer is air - dryer and drying ovens are suitable for all fabrics, even for those who really should not be dried by machine.

Dryer balls

Commercially balls with nubs are offered, accompanied by pairs of underwear, designed to speed up the drying process. These balls loosen up on the laundry, so that the air has more attack surface. In addition, the washing should be even softer by the balls.

Power consumption

The total power consumption (washing machine plus dryer), by choosing a high spin speed can be reduced (eg, 1400 rpm). The Spin efficiency class of washing machines with 1400 rpm. is only 'B' ( residual moisture 45 to < 54 percent). Washing machines with 1600 rpm. have only slightly less residual moisture; those who have less than 45 % residual moisture Spin efficiency class A. A higher speed causes more especially crease; the marginal benefit is marginal.

Clothes have been criticized for their often high power consumption, which many people by conventional drying ( see: alternatives to dryer) could be avoided.

Energy labels are mandatory in the EU. Inform about power consumption and energy efficiency and bring about a certain degree of market transparency. Until 29 May 2013, there was the energy efficiency classes A to G; since that date there is a new EU energy label, which identifies additional energy efficiency classes. The best category is from now A , the lowest energy class corresponds to Class D. As of November 2013, all new equipment in the trade must at least meet the requirements of energy efficiency class C, from November 2015, the energy efficiency class B. consume Tumble Class A about 70 percent less electricity as a Class B. The higher purchase price for a more efficient device class pays for itself after a certain number of hours of operation.

2007 calculated the energy information agency of the U.S. government that clothes dryers are responsible for six percent of electricity consumption of American households. In the U.S., clothes dryers are more common than in Europe; in some areas of the U.S. it is considered a sign of poverty or anti-social behavior to dry laundry outside. In some neighborhoods or cities in the United States was or is even forbidden.

Equipment rate

The Federal Statistical Office has made ​​an equipment rate of 38.6 percent in private households in Germany for the year 2009. On 1 January 2011 possessed 39.7 percent of households had at least one dryer. In 2010, sales amounted to 495 million euros with clothes dryers in Germany.