Unit 2: Consumption of energy at home
In this section your task is to evaluate the energy consumption and power of various electrical devices including devices for heating.
As energy consumption and economy are not new ideas can be shown by the story of little girl Pille, written more than 40 years ago.
The list of electrical devices is wide in our stores. On the store counters you can often see the products, the purpose and use of which you can’t even guess always. The most commonly used electrical devices in our homes are TVs, radios, tape recorders, sewing and washing machines, vacuum cleaners, irons, coffee grinders and jugs, power tools, shavers, hair dryers, electric radiators and fireplaces, humidifiers, quartz lamps, fans and more. Although some of them are used quite rarely, Pille can apply her basic rules of energy saving to them, for example:
- Switch off the TV or radio, when nobody is watching or listening the shows;
- Use the vacuum cleaner only for cleaning the devices and textiles that cannot be carried outside for churning;
- Switch the iron on just before the beginning of ironing and switch off right after the end of the working;
- Use the more powerful energy consumers such as quartz lamps and heat radiators as late as possible when the peak energy use hours are over;
- Not to buy the electrical devices which purpose is not known exactly, or which remain in a closet.
Source: Hans Karro “Story of Juhan, Pille and energy”.
Tallinn “Valgus” 1979 (p. 14).
As we can see there are many devices which are not used anymore. Energy consumption of TVs and radios is decreased significantly, but energy use of iron is probably the same as 40 years ago.
Exercise 2.1
To be more aware which electrical devices need more power and the practical use of which can save more energy, here some devices are listed. Your task is to align the devices with suitable power values. Just drag the words.
Problem 2.1
Here you should find all the electrical and heating/cooling appliances, and their nominal power consumption in your household (e.g. house, apartment etc). Also, a total energy consumption during one week. To be more specific, let it be one week in October or in March.
Let us consider that the energy E consumed during time t is connected with a power P by a formula E=P∙t. So you can find total energy by specific electrical appliances. Add data about heating appliances (radiators using central heating sources, gas, etc. as well as electrical radiators) to another column. Discuss with your fellow students how to find the power of heating appliances. The software environment for this table (e.g. MS Excel, LibreOffice Calc, Google spreadsheet) is suggested by your supervisor. The example of that table is given in Table 1.
Tabel Google sheet´s. You can copy it and fill it. In some rows also the formulas are given.
Table 1. Power and total energy consumed by appliances in a household.
