How it works: Electric devices for improvement of air quality

Depending on the season, climate and susceptibility to allergies there are different requirements for the condition of the indoor air. Ideally it should have a balanced vapour content, have a pleasant temperature – not too warm, not too cold – and of course it should be free from germs, pollutants and allergens. This guide will explain in detail what the different articles in our range do exactly to help you optimise air quality in your home. The air treatment and purification will no longer pose any problem, even large spaces can be treated!

Reading time: 13 min or skip right to the summary


  • What kinds of appliances are there?
  • Improving air quality in old and new buildings (how to ventilate)
  • CADR filter specs
  • Cross reference protection from insects
  • Summary

What kinds of appliances are there?

Our range includes appliances that help optimise air quality by controlling and regulating the water vapour content inside the house, and clean the air from contaminants and bacteria. The three product sections are: Dehumidifier, Humidifier und Air purifier.

Device type: Dehumidifier Humidifier Air purifier / Air washer
Application: Reduces excess water vapour Humidifies dry air Filters / washes dust, pollen, animal hairs, odours, etc.
Purpose: Drying humid indoor air, preventing mould growth Preventing nervous cough due to warm air, reducing susceptibility to infection Providing clean indoor air without pollutants, allergenic or pathogenic particles
Method: Condensation drying:
Shock cooling of indoor air inside the device, released vapour condenses and is collected.
  • Ultrasonic mist
  • Vaporisation at boiling point
  • Evaporation
  • Prefilter
  • Activated carbon filter
  • HEPA filter
  • Electromagnetic HPP filter
  • Water filter bath
Use: Domestic and commercial environments Domestic and commercial environments Domestic and commercial environments
Room size: up to 70m2 up to 100m2 up to 80m2
Extras depending on brand: Oscillation, auto off, timer Adding scented oils, timer, night mode Night mode, various levels, indicator for filter replacement

All of the three product lines are suitable for use at home or in commercial areas. Amongst others this includes office buildings, restaurants and guesthouses. Would you like to learn more about the possible range of applications? Find out more in the description of our "category for air treatment"

Here we have compiled the basic production characteristics for you:

In living quaters the daily use of the shower, kitchen, washing machine, etc. generate several litres moisture every single day that saturate the air inside the room. The water vapour inevitably gets into contact with with cold spots like windows and begins to condense. Small drops and occasionally water accumulation form in these spots that offer ideal breeding ground for germs and bacteria, even fungal spores can begin to thrive and prosper. Electric high performance dehumidifier like the Stadler Form Albert model are designed to rid indoor air of excess moisture. An integrated hygrostat measures the current vapour content and automatically begins operating once the humidity hits a critical level. The excess water is collected in a tank and can be disposed of later on.

Humidifiers can be used year-round, however they usually become an indispensible accessory during the colder season when the radiator is turned on most of the time. Artificially warmed indoor air tends to be quite dry and actually promotes irritation of the mucosa and susceptibility to infection. Humidifying appliances with a chic design add moisture to the indoor air until it has reached a more agreeable condition. The clever thing about is that water vapour is not emitted completely at random, in fact it is measured and controlled by a hygrostat. There are three kinds of mechanical humidifiers that add moisture to the air in a different way:

The ultrasonic system nebulises water from the tank by using high-frequency waves until a super fine mist is generated. These liquid airborne particles, also called aerosoles, are transported directly into the lungs when breathing in. For that reason the liquid used in the water tank must be completeley free from germs. Look out for high-quality brands with filter or cleaning systems when choosing a product on By adding silver ions to the water fungi, germs and bacteria can be killed to ensure sanitary condition of vapour. Many devices also come with a built-in container for optional fragrance that can be dispensed in the room.

Vaporisers come with an integrated heater plate on the inside that boils water. During the process any germs are killed off. Adding anti-limescale accessories to the water (often already included in the delivery) prevent mineral deposits in the device and the room. A sensor or hygrostat measures the vapour contents of the air and automatically switches the unit off as soon as the desired (preset) level is reached.

Evaporators dispense tiny water molecules with the help of a fan. This offers a nice co-benefit: Some models can be used for a cooling effect only, for example during the hot summer months! Integrated filters ensure that the water that is spread stays hygienic and clean. It goes without saying that these models come with a wide range of features, such as adjustable humidity levels or timer.

Air purifiers do not alter the humidity level of the air (except for the multi-functional Robert), they simply remove unwanted “additions” like dust, mites, pet hairs, virus, bacteria and fungal spores. They are often used in households with people suffering from allergies. Another field of application is the filtration of odours and high pollutant concentration (fine dust near roads). Hence, they are rather versatile and can be set up anywhere ranging from a restaurant to office buildings and naturally, the flat. The device gradually takes all of the room air in where it passes through a filter system (carbon, HEPA or water) and distributes the clean air evenly throughout the entire space (up to 80m2 per unit). An integrated fan or rotating evaporator discs ensure efficient air circulation.

The installation of the devices is done effortlessly, they are simply connected to the circuit by plugging them into the wall socket. This means they are ready for use as soon as they have been taken out of the package. The appliance can be placed in any spot in the room. Ideally the unit is set up in or around the centre of the room to ensure maximum efficiency and wide-scale coverage. Check the manual for specifications and instructions, models without IP rating for example are not suitable for use in kitchens and bathrooms.

All products for air treatment of the different brands in our range are durable and highly efficient. They only vary in their user-friendly features and product design. Apart from technical specifications the purchase also subject to personal taste since the appliance is usually set up in the centre of room and should have an appealing design. More information about different designs is available in our guide about the "design" of these products.

Improving air quality in old and new buildings (how to ventilate)

Devices that support the retention or improvement of the air quality in the room are suitable for application in old and new buildings regardless of the presence of ventilation systems. Keep in mind though that the units can only treat the air that is already there inside the room, they do not substitute the required fresh air supply. In old buildings this can be done by opening windows, or even decentralised ventilation units in rooms without windows. Keep in mind that warm air transports more moisture than cold air. If there is already a problem with humidity on-site, try to ventilate at night or in the early hours of the morning. 

Having a method of external air supply (windows or ventilation system) that starts up whilst your device is operating will not have any negative impact on its cleaning efficiency. However, it is not very desirable to have both run at the same time because the cleaned or treated air would escape too soon without being used. The better option is to switch on the humidifier, purifier or dehumidifier after ventilation system has finished a cycle of supply and extraction.

In newly built houses with a central ventilation system and sensor-controlled humidity adjustment the short-term use of air treatment devices comes in handy, too. Air purifiers in particular increase the performance of on-site filter systems to a point where people with allergies and asthma feel comfortable and safe. Filters in ventilation systems and ducting only remove coarse particles like dirt and dust (depending on model and brand), but they are not equipped to deal with fine matter and micro-organisms. Odours are also not completely trapped by all systems and might spread throughout the entire living quarters. A portable air cleaner that you can use spontaneously whenever the need arises is a valuable addition to the household!

Filters in professional ventilation systems with ducting must be cleaned or replaced frequently. If their capacity limit is reached soon you can choose to use portable air cleaner to support the performance during the last few weeks before the appointed day of the replacement.

CADR filter specs

Various manufacturers like to state CADR figures for a better comparison to their descriptions and specs of the air purifiers. CADR (Clean Air Delivery Rate) describes the rate of cleaned air that is delivered in cubic feet per minute. The test is done in a room with a size of 1008 cubic foot / 28.5m3 and measures how much air is cleaned in a certain time limit. The figures are measured by the independent AHAM (Association of Home Appliance Manufacturers), taking part in the procedure is voluntary, each brand decides individually if the performing of the test is desired. Seeing that this rating has become internationally recognised and established, most manufacturers send their products to the institute.

Three CADR figures are determined per device: one for smoke, dust and pollen each. The reason for testing all three is that the particles have a different size. Depending on the filter type and how many filters are used inside the air purifier, the particles are trapped better or worse. Devices with several filters with various grades, e.g. prefilter, activated carbon filter and HEPA filter, often have excellent results in all three categories.

Despite this significant basis of comparison to other air cleaners a good CADR assessment should not be the only factor by which a decision about the purchase should be made. Look out for ease of use, high-quality manufacturing and especially the operational noise.

CADR figure: dust 152, pollen 170, smoke 142 

Cross reference protection from insects

However, not only fine dust and high humidity negatively impact the indoor air quality, flying insects such as fruit flies and mosquitos give residents a hard time. Particularly in cattle breeding and catering trade insects are not only annoying, they actually pose a risk to health because they act as tiny germ carries. We offer high-performance insect killers with UV lamps, glueboard and electric grid that get rid of the pests in an efficient and quick way. Insect traps with an integrated fan give users the possibility to let beneficial insects free after they were caught in a tray and can cover a wide range of up to 180m2.

Flykilles and insect traps can be used at home, in commercial or industrial environments. For use in agricultural and industrial areas it is important to look out for the IP rating.

Find out more about the different device types in our guide or in the product category. More useful tips are available in our blog "about insects in the summer".


Electric devices that help improve indoor air quality can be divided into three classes: humidifier, dehumidifier and air purifier. The first two product lines serve to optimise the humidity level in the room to prevent too much moisture (risk of mould growth) or too little moisture (irritation of the mucosa). The ideal indoor humidity level contains 40-60% water. In contrast, air purifiers are used to filter allergens, bacteria, odours and small particles from the air. The efficiency of the different products can be compared by looking at the CADR figures. There are also products that combine two functions such as the air washer Robert that is able to clean the air and humidify if need be.

Learn more about why exactly clean air is so important for our bodies in our blog "How much oxygen does a human need".

Picture sources:
Product pictures ©
Filters © Shestakoff -
Wasp © Oldiefan -, CC0 Public Domain