A shoe dryer or boot dryer is a machine used for drying shoes, and usually functions by blowing air on the inside of the shoes. The airflow causes the shoes to dry faster. The air can be heated for even faster drying, and these are the most common types. [1] Shoes dryers can be especially useful for people who often have wet shoes, such as families with small children or people who often hike outdoor in the nature, or for ski boots which often are moist after use. Many shoes dryers have a timer which shuts off the dryer after some time. [2] There are also shoe dryers which instead use a heated grate which the shoes are placed on top of, and which do not blow air.
Several patents have been awarded for shoe dryers, [3] [4] [5] [6] [7] [8] with some of the oldest dating back to 1963. [9]
Many fan-driven shoe dryers emit bothersome noise during use. [10] In a test from 2019, the most silent model was measured at 45 decibel (dB), [11] while the other models were measured at 50 and 57 dB. In 2022, another model was measured at 56 dB in "tornado" mode and 29 dB in "whisper" mode, [12] and in 2023 another variant of the same dryer was measured at 72 dB. [13] It was also commented that the higher pitch of the said models noise could contribute to it being perceived as more intense and bothersome. [13]
The volumetric flow rate, i.e. the amount of air that is moved, is an important measure of fan-based shoe dryers. For example, a model tested in 2023 was stated to have a volume flow of 12 cubic meters per hour (m³/h), which corresponds to 12 000 liters per hour or just over 3 liters of air per second. [14] Larger diameters of tubing and fans are beneficial for increased volumetric flow, and also results in lower air speed and thus less noise.
Shoe dryers with a fan often emit slightly lukewarm or warm air. In a test from 2019, one of the models was rated at a power of 350 watt, [11] of which 30 W was utilized as fan power and the remaining around 320 W were used for heating. Another model in the test had two temperature settings for choosing between 40 °C and 55 °C air temperature. [11] A model tested in 2023 had settings for blowing air at room temperature, or heated air at 37, 45 or 60 degrees Celsius. [12] [13]
Not all shoes can withstand heated drying. [15] Using high heat can put wear on shoes made of certain materials, and for example the use of a tumble dryer, heating cables or heating cabinet can lead to leather shoes cracking. [15]
Shoe dryers with heating can be a fire hazard if left on for too long, and should therefore be used under supervision. [10]
Spray drying is a method of forming a dry powder from a liquid or slurry by rapidly drying with a hot gas. This is the preferred method of drying of many thermally-sensitive materials such as foods and pharmaceuticals, or materials which may require extremely consistent, fine particle size. Air is the heated drying medium; however, if the liquid is a flammable solvent such as ethanol or the product is oxygen-sensitive then nitrogen is used.
A clothes dryer, also known as tumble dryer or simply dryer, is a powered household appliance that is used to remove moisture from a load of clothing, bedding and other textiles, usually after they are washed in a washing machine.
Nichrome is a family of alloys of nickel and chromium commonly used as resistance wire, heating elements in devices like toasters, electrical kettles and space heaters, in some dental restorations (fillings) and in a few other applications.
A blower door is a machine used to perform a building air leakage test. It can also be used to measure airflow between building zones, to test ductwork airtightness and to help physically locate air leakage sites in the building envelope.
A kitchen hood, exhaust hood, hood fan, extractor hood, or range hood is a device containing a mechanical fan that hangs above the stove or cooktop in the kitchen. It removes airborne grease, combustion products, fumes, smoke, heat, and steam from the air by evacuation of the air and filtration. In commercial kitchens exhaust hoods are often used in combination with fire suppression devices so that fumes from a grease fire are properly vented and the fire is put out quickly. Commercial vent hoods may also be combined with a fresh air fan that draws in exterior air, circulating it with the cooking fumes, which is then drawn out by the hood.
A hair dryer, hairdryer or blow dryer is an electromechanical device that blows ambient or hot air over damp hair to speed the evaporation of water to dry the hair. Blow dryers enable better control over the shape and style of hair, by accelerating and controlling the formation of temporary hydrogen bonds within each strand. These bonds are powerful but are temporary and extremely vulnerable to humidity. They disappear with a single washing of the hair.
EU Directive 92/75/EC (1992) established an energy consumption labelling scheme. The directive was implemented by several other directives thus most white goods, light bulb packaging and cars must have an EU Energy Label clearly displayed when offered for sale or rent. The energy efficiency of the appliance is rated in terms of a set of energy efficiency classes from A to G on the label, A being the most energy efficient, G the least efficient. The labels also give other useful information to the customer as they choose between various models. The information should also be given in catalogues and included by internet retailers on their websites.
A humidifier is a household appliance or device designed to increase the moisture level in the air within a room or an enclosed space. It achieves this by emitting water vapor or steam into the surrounding air, thereby raising the humidity levels.
A sound attenuator, or duct silencer, sound trap, or muffler, is a noise control acoustical treatment of Heating Ventilating and Air-Conditioning (HVAC) ductwork designed to reduce transmission of noise through the ductwork, either from equipment into occupied spaces in a building, or between occupied spaces.
Induction cooking is performed using direct electrical induction heating of cooking vessels, rather than relying on indirect radiation, convection, or thermal conduction. Induction cooking allows high power and very rapid increases in temperature to be achieved: changes in heat settings are instantaneous.
Dielectric heating, also known as electronic heating, radio frequency heating, and high-frequency heating, is the process in which a radio frequency (RF) alternating electric field, or radio wave or microwave electromagnetic radiation heats a dielectric material. At higher frequencies, this heating is caused by molecular dipole rotation within the dielectric.
A fan heater, also called a blow heater, is a heater that works by using a fan to pass air over a heat source. This heats up the air, which then leaves the heater, warming up the surrounding room. They can heat an enclosed space such as a room faster than a heater without a fan, but like any fan, create a degree of noise.
A hand dryer is an electric machine which might make use of a heating element and an air blower to dry the hands after hand washing. It is commonly used in public toilets as a cost-effective alternative to paper towels.
A food dehydrator is a device that removes moisture from food to aid in its preservation. Food drying is a method of preserving fruit, vegetables and meats that has been practiced since antiquity.
Radiators and convectors are heat exchangers designed to transfer thermal energy from one medium to another for the purpose of space heating.
Solar air heating is a solar thermal technology in which the energy from the sun, insolation, is captured by an absorbing medium and used to heat air. Solar air heating is a renewable energy heating technology used to heat or condition air for buildings or process heat applications. It is typically the most cost-effective out of all the solar technologies, especially in commercial and industrial applications, and it addresses the largest usage of building energy in heating climates, which is space heating and industrial process heating.
Grain drying is process of drying grain to prevent spoilage during storage. The grain drying described in this article is that which uses fuel- or electric-powered processes supplementary to natural ones, including swathing/windrowing for drying by ambient air and sunshine, or stooking before threshing.
Pasta processing is the process in which wheat semolina or flour is mixed with water and the dough is extruded to a specific shape, dried and packaged.
A drying room is a room intended for drying objects. It can act as a replacement or complement for drying cabinets, tumble-dryers, and outdoor drying. Compared to outdoor drying, a drying room means one usually does not have to consider the weather forecast in case of rain.
Beha SKO 300T (45 dB, 300 W) rated 5/6, Biltema Art. Nr. 84-149 (50 dB, 350 W, 320+30 W), Adax Neo (50 dB, 220 W) rated 5/6, Clas Ohlson SD-018 (57 dB, 265 W, 40 or 55 °C) rated 5/6.