Title: How weather affects laundry: What temperature, humidity level and wind speed are the best for drying clothes?
Subject: Renewable Energy
Subcategory: Green Energy
Grade level: Primary School - Grades K-3
Academic Level: Ordinary
Project Type: Experimental
Awards: 1st place, Canada Wide Virtual Science Fair ($50)
Affiliation: Canada Wide Virtual Science Fair (VSF)
Materials: One white cotton hand towel, one coloured cotton sock, clothes pins, clothesline
Concepts: The clothes line
Description: Step One: Hang up wet sock and towel. Check the time and the weather on the Yahoo! weather app and write them down. For weather, check the humidity, temperature and wind speed. Step Two: Keep checking the weather and the wet items until both are dry. Step Three: Measure the time it took for each thing to dry in those weather conditions. Repeat the experiment several times with different weather conditions.
The Clothes Line
Clothes line: laundry is blowing in the wind
Attribution: CC 3.0 Unported (Michael Gäbler)
Advantages of a clothes line
- Saves money
- Zero greenhouse gas emissions per load (2 kg CO2eq of greenhouse gas emissions from the average mechanical clothes dryer per load)
- Less fabric wear and tear
- Laundry items do not shrink (hot air from a mechanical clothes dryer may shrink items)
- No static cling
- Laundry items stay softer to the touch (mechanical clothes dryers tend to remove short, soft, fine fibers), and may be less wrinkled
- Laundry items often do not need ironing if line dried in a breeze
- Avoids the potential of airborne lint and reduced air quality
- Eliminates the noise from a mechanical clothes dryer
- Does not vent to the outside and waste the large volume of conditioned (heated or cooled) indoor air that a mechanical dryer's blower does.
- For a simple line drying arrangement (rope and clothes pins) the repair and replacement costs are about $20.00 per 1,000 loads of laundry or 2 cents per load. For non-commercial mechanical clothes drying the repair and replacement costs (including labor expenses) are about $200.00 per 1,000 loads of laundry or 20 cents per load.
Disadvantages of using a clothes line
- Putting laundry on a line usually takes more time than putting it into a mechanical dryer (as laundry items have to be hung up and fixed one by one).
- Laundry items need to be hung indoors during rainy weather, or may get wet if the weather changes.
- Neighbours may find it aesthetically unpleasant
- Exposing dirty laundry can lessen privacy, showing information about inhabitants' living habits.
- Risk of theft or vandalism of clothes
- Environmental contaminants such as soil, dust, smoke, automotive or industrial pollutants, pollen and bird and animal droppings can come in contact with clothing.
- Clothespins can leave imprints (including rust from the spring) on the clothes.
For example, laundry on a clothes line will dry (by evaporation) more rapidly on a windy day than on a still day. Three key parts to evaporation are heat, atmospheric pressure (determines the percent humidity) and air movement.
When clothes are hung on a laundry line, even though the ambient temperature is below the boiling point of water, water evaporates. This is accelerated by factors such as low humidity, heat (from the sun), and wind. In a clothes dryer, hot air is blown through the clothes, allowing water to evaporate very rapidly.
See also: https://en.wikipedia.org/wiki/Clothes_line
Source: Wikipedia (All text is available under the terms of the GNU Free Documentation License and Creative Commons Attribution-ShareAlike License.)