Does the dishwasher save water: unexpected result

According to experts, a dishwashing machine saves money for the family budget. This statement seems controversial, because it is quite an expensive technique. However, simple calculations show that the machine spends noticeably less water than it goes into the drain when washing by hand. We carry out the calculations and determine whether this savings justifies the cost of acquiring a dishwasher.

Washing dishes by hand and in the dishwasher

Define the conditions for comparison

Of course, any comparisons in the field of households will be approximate enough without a precise definition of the objects to be compared. Each dishwasher has its own set of characteristics, which determine how many liters of water and kilowatts of electricity will be spent on one cycle. With manual washing, you can also apply various techniques that save water (or, conversely, increase consumption).

Talking about savings is possible only with the use of modern technology. As an object for comparison, the model of a dishwasher from Bosch was selected: SPV 40E30. This is a relatively narrow machine (its width is 45 cm). Here are its main indicators:

  • The energy consumption class in washing and drying mode: A. This means that the machine spends 0.78 kWh in the ECO washing mode - 50 ° C.
  • The capacity of the loading compartment is approximately 9 sets of dishes.
  • The full cycle time (washing and drying) is about 2 hours.

As an alternative, the regime of manual washing was chosen under a stream of running warm water. In this mode, 9 sets of dishes can be washed in 30–40 minutes. It is worth saying that such a dishwashing (this method is most common in Russia and the former Soviet Union) is considered by experts to be very uneconomical.

Water meters

Is water saving?

An analysis of the indicators of the hot and cold water supply meters allows us to state that about 70–75 l of hot water and 30–40 l of cold water are spent in one “session” of manual washing in the described mode. Of course, this amount can be slightly reduced if you periodically open and close the water (for example, while washing dishes). However, such savings will increase the time of the procedure and require a lot of effort.

According to the instructions for the dishwasher, taken as an object of comparison, the flow rate for one cycle should be approximately 9 liters of cold water. Actual consumption (set using the meter) was 10 liters.

Water consumption is significantly affected by its hardness. Soft water (containing few Ca and Mg ions) can wash detergents worse, so it is consumed in large quantities. At the same time, hard water shortens the life of the machine.

The calculation of the cost of washing dishes in the selected modes gave the cost of one hand wash - 15.4 rubles, and machine - 5.5 rubles. For calculations, the following tariffs were taken:

  • 1 cc m of hot water, taking into account sanitation - 178.19 rubles.
  • 1 cc m of cold water, taking into account water disposal - 57.12 rubles.
  • 1 kW of electricity during the day - 3.71 rubles. (At night, the cost of 1 kW is 2.07 rubles. Therefore, if you start the car at night, one cycle will cost about 3 rubles.)

If we assume that we will wash the dishes in this mode once a day, then for the year we will spend 5.5 thousand rubles on hand washing. Using the machine will save almost 3.5 thousand rubles.

The girl is pleased with the result of the dishwasher

Extra bonuses

In addition to the fact that the machine significantly saves water, its use brings some additional bonuses:

  • The high temperature of washing dishes in the machine (in some models it can reach 90 ° C) will ensure almost complete sterilization of the dishes. This advantage will be appreciated primarily by families with infants.True, reaching such high temperatures will increase electricity consumption and reduce savings.
  • The use of softening conditioners during washing will ensure impeccable cleanliness of the walls of glassware, unattainable in hard water regions in any other way.
  • As with washing machines, the principle applies: the larger the volume of the dishwasher, the greater water savings are achieved in 1 cycle.

The main bonus, no doubt, is the time saved. Of course, before loading into the machine, the dishes will have to be cleaned from large solid pieces of food, sorted and carefully laid out in brackets. But it will take no more than 15 minutes, and the rest of the time you can devote to other household chores, leisure or hobbies.

Woman loads the dishes in the dishwasher

Should I buy a dishwasher?

Before deciding to buy a dishwasher, you must weigh all the pros and cons. First of all, evaluate the dimensions of your kitchen and think about whether the new unit will fit into it. Also appreciate how much capacity you really need.

It should be understood that some types of dishes will still have to be washed by hand. This is large-sized dishes (pans, baking sheets, large pans), as well as dishes with unstable spraying (Teflon pans, plates with a metal border, etc.).

Calculations show that the dishwasher will pay off completely in 3.5–4 years of operation. With an average period of use of such equipment in 5 years, this suggests: the dishwasher is not only an assistant in the household, but also saves water.

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  1. Anastasia
    08/30/2019 at 11:08 Reply

    In the dishwasher, baking trays, large pots and grills from stoves are perfectly washed. The main thing is that the basket is adjustable in height and there will be no problems. I do not know why to write that it is washed by hand. Lampshades (with a picture it is better not to risk it), vases, soap dishes and the like household things are also perfectly washed.

  2. Oksana
    08/30/2019 at 12:37 Reply

    Add to all this the cost of PMM + for the cost of cleaning products in the PMM and find ourselves in a big minus. Especially if in the summer I wash only with cold water. My dishes are only households. soap, the rest of the chemistry our body does not digest.

    • Yuri
      11/16/2019 at 16:03

      You can save even more if you wash it manually with a washboard and rinse it on the pond.

  3. Oksana
    08/30/2019 at 12:58 Reply

    Add to all this the cost of PMM + the cost of washing products in the PMM and we find ourselves in a big minus. Especially if in the summer I wash only with cold water. My dishes are only households. soap, the rest of the chemistry our body does not digest.

  4. Juran
    09/01/2019 at 10:00 Reply

    The savings are very doubtful - the price, special dosed washing tablets (from 4 rubles each), the use of only cold water (you need electricity, but it is also not cheap now). For 3 years of payback, maintenance / repair may be necessary - then in general a pipe, the cost of spare parts is impressive. You need to have a “supply” of dishes, one or two cups / plates you will not wash until the next batch is “accumulated”. Does it still take water to wash it manually, wash it in a dishwasher after every glass of milk? When manually washing, 70 liters of hot water and 40 liters of cold water? Yes, 9 more sets (it is necessary to keep the 10th reserve, when washing in the PMM, suddenly someone comes to visit). Water consumption depends on the season, do not you think? With the flow, you turned down, I have separate counters in the kitchen, for a month there is a maximum of 1 cube of hot and cold water (i.e. ~ 30l + 30l per DAY)

    • Lina
      09/02/2019 at 17:21

      term of use - almost 10 years, now the second has been bought, the first has served. not even a bit of doubt arose to buy a second or not.the mother-in-law in the village also has a machine, life is simplified, my mother-in-law is insanely happy and glad. and real savings are present.

  5. Mike
    09/01/2019 at 12:35 Reply

    Saving time is the main thing. Do not run the machine to wash a couple of cups. To save electricity, you can wash it with a delay after midnight, if a multi-tariff meter. So use the machine with a full load, other detergents, optionally expensive tablets, can be used as a detergent. And there will be free time for the family.

    • Mike
      09/01/2019 at 12:03

      Yes, and do not save on a car, take the maximum capacity if there is a bit of space in the kitchen. Now we use a machine for 14 people with three trays and height adjustment.

  6. Yayaya
    09/01/2019 at 23:04 Reply

    The mmm machine was invented in Europe where a cube of water costs more than a couple of hundred rubles, and the hour of time for a woman engaged in washing dishes is more than zero.

  7. Oksana
    09/02/2019 at 10:55 Reply

    Given the cost of the PMM itself and consumables, it’s cheaper to wash it manually with households. soap. Moreover, in the summer I generally do not turn on hot water when washing dishes.

    • Elena
      09/17/2019 at 19:49

      PMM greatly frees up personal time. As for household soap, it is now not of the best quality. Hand washing is not easy enough. You didn’t check the dishes after washing?

  8. Alexander
    09/03/2019 at 12:20 Reply

    if the conversation is only about saving, then due to consumables manually it is still cheaper. I have been using the machine for five years, very pleased. No one in this article said anything. that when we wash the dishes by hand, there are also consumables and electricity that illuminates the room. Therefore, the difference is negligible. But the convenience is just wonderful. Now it does not occur to anyone to refuse a washing machine. I think the same time will come for the dishwasher. All households put their dishes in the car and in the evening when meals are finished you take a pill, insert where you need to press the button and go to bed, and in the morning you get a consistently excellent result in the form of dry perfectly clean dishes. Good luck to everyone and greetings from Nizhny Novgorod.

  9. Alexander
    09/03/2019 at 13:43 Reply

    I completely forgot when guests come after a feast, they don’t want to wash anything at all. threw it over quickly, pressed a button and rest. the beauty.

    • Farida
      11/06/2019 at 20:06

      👍

  10. Andrey
    09/04/2019 at 17:44 Reply

    The consumption of water and electricity has been calculated, but the lion's share of the price is made up of special detergents. Having added their cost you will understand that the dishwasher will never pay off. But there are such words as: convenience and comfort! It is for this and buy a dishwasher.

  11. Ravil
    09/05/2019 at 23:17 Reply

    The article itself is about nothing. But here in the comments, people find it unprofitable to use a dishwasher because of powders and other crap. The value of this device is immediately obvious to people who value time. This device gives you the only irreplaceable resource TIME!

  12. Marianne
    09/06/2019 at 14:39 Reply

    Laundry soap ... .... If the only question is saving, then you can don’t wash the dishes at all. Or, for example, once a week.

  13. Yuliya
    09/06/2019 at 15:34 Reply

    To wash dishes from laundry soap, which has a high concentration of alkali, it is necessary to douse it with boiling water. Otherwise, you will eat soap every day with food. Enjoy your meal!

  14. Michael
    09/16/2019 at 21:03 Reply

    if rinsed immediately after a meal by hand, WATER CONSUMPTION FALLS THREE.

  15. Lyudmila.
    09/18/2019 at 11:13 Reply

    The benefit is only in the free time of the hostess. If the dishwasher saves only 2,000 rubles a year (for water), then can it really pay off in 3.5-4 years? It turns out that the dishwasher should cost 7-8 thousand rubles. I looked on the Internet for the cost of a compact budget dishwasher - 14,000 rubles. What is the result? As a result, the cheapest pays off only after 7 years.

  16. Natalia
    09/23/2019 at 05:16 Reply

    A pack of soda, rubber gloves - for two months, a 4-5 liter bowl for 10 years, heat 1.5 liters. water for washing and the same amount for rinsing 3-4 sets of dishes. Bonus calorie expenditure on labor.While washing, you can listen to something - an audio book, music or news. Therefore, the words about saving on dishwashers cause a slight grin.

    • Farida
      11/06/2019 at 20:33

      Bravo! I agree with you all 💯!
      And washed by hand without detergents and in complete darkness. And I will not say anything about the quality of washing with my household.
      10 years I have a machine. And if it breaks, then without a doubt, I will run for a new one. My husband and I live together, the daughter grew up and lives separately as her family. Together we fill the machine))) we have a big one. And pots and pans glass.
      In addition to aluminum (meat grinder) and Teflon. No plaque on spoons or cups of tea. Clean forks and plates. Which "crunch" from cleanliness)))

    • Farida
      11/06/2019 at 20:50

      Still to this wash basin to buy a board for washing and the washing machine is not needed. What? She most likely will not pay off either. He rubbed it on the board with the same household so that it would not be wasted on powder and fabric softener, and an iron is not needed. We saw how expensive they are. You can also use a rolling pin on the table, as in ancient Russia, again, saving energy. And the waist will become thinner пот

  17. Kirill
    09/25/2019 at 23:31 Reply

    It is necessary to use it to a minimum. It perfectly launders dishes. But it’s saving. They ate, washed with soda and economically and environmentally friendly. They downloaded everything a couple of times a week and washed again

  18. Olga
    11/12/2019 at 21:40 Reply

    With our Hotpoint dishwasher, time is saved in the first place, and the saving of water, of course, is available, although at first it is not very noticeable.

    • Yuri
      11/16/2019 at 17:19

      +1 In addition, I live outside the city, the call of scavengers costs decent money. If you pour 100 liters three times a day, then you will remain without pants.

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