Using an electric boiler in an apartment or a private house is the easiest and most affordable way to provide the house with hot water (DHW). Accumulative type water heaters do not require installation permission and a powerful power input, since they consume only 2-3 kW / h of electricity. But the latter costs a lot of money, so homeowners have a logical question - how to use a water heater to save electricity. We will try to give a detailed answer to it.
Briefly about the device and principle of operation
In order to save money, users try to turn on the boiler according to a certain schedule. But if you want to reduce energy consumption during operation of a water heater, you need to understand in general terms how it functions.
The picture below shows the storage boiler - a heated tank made of stainless steel or enameled steel with a built-in tubular electric heater (TEN), which has its own thermostat. At the bottom there are nozzles for supplying and withdrawing water; in the same place (or on the front panel) there is a heating controller and a thermometer.
The algorithm of the water heater looks like this:
- Through a pipe equipped with a check and safety valve, the tank is filled with cold water. The heater is automatically turned on and the heating process begins.
- When the contents of the tank reach the temperature set by the user, the thermostat turns off the electric heater. If there is no water intake, the automation maintains heating at a set level, periodically turning the heater on and off.
- When the hot water tap is opened on any mixer, water is drawn from the upper zone of the tank where the corresponding pipe is discharged.
For reference. Boilers are not only electric, but also gas. In them, heating is carried out not by the heating element, but by burning liquefied or natural gas. A comparison of various storage units with flow columns is described in another publication of ours.
So that the electrochemical reactions that occur between dissimilar metals during the heating process do not cause corrosion of the steel tank, a magnesium anode is mounted in it, taking the “blow” on itself. That is, due to the activity of this metal, the rod is gradually destroyed instead of the tank and the heater.
Installation and connection of a boiler
An important role in saving light is played by the correct installation and strapping of a household appliance. Before you install and turn on the water heater, be sure to read the operating instructions, especially if you decide to perform these works yourself. We will give a few general requirements set forth in the manual for common Ariston units (Ariston):
- to connect the water heater to the mains, use a copper cable with a cross-section of 3 x 2.5 mm²;
- the device must be grounded and powered by a separate line with an automatic bipolar switch, and not just insert the plug into the first power outlet;
- since the weight of the boiler is 50-100 liters is quite large, fasten it to a reliable base, for example, to a major partition;
- models intended for vertical or horizontal installation, mount in the specified position;
- Connect the unit to the cold and hot water supply network as follows:
An important role is played by a non-return valve, which does not allow the tank to empty into the water supply in the absence of pressure. He also acts as a fuse - discharges water, expanding in case of overheating. Therefore, from the "nose" of the valve should be a flexible tube in a plastic bottle or send it to the sewer.
A tee must be placed above the valve with an additional drain valve. If you do not use the boiler for a long time or there is a danger of freezing, then the water must be drained, and without a tap this procedure is greatly complicated. For the convenience of dismantling the apparatus, the pipes are connected to the fittings through the American women.
Tip. When it is not possible to attach the water heater to the main wall, make a simple metal stand of 2 pipes and strips, as shown in the photo.
Before turning on the boiler, you need to open the nearest DHW tap in the apartment and fill the tank with cold water until it flows out of the mixer. Then close the valve and put the machine into operation.
How to save electricity
There are several ways to really reduce the cost of preparing hot water:
- Adjust the temperature on the boiler in such a way as to eliminate unnecessary electricity consumption, but without reducing the comfort for the residents of the house.
- The simplest and most accessible method for everyone is not to heat the water when it is not needed.
- To save energy, you can use additional sources of heat obtained at more favorable prices.
- Time to clean the internal elements of the unit from scale and abandon the schemes with DHW recirculation.
The maximum heating temperature in most household appliances is 75 ° C. Considering that in winter the water supply is often cooled to 8-10 ° C, an 80-liter electric heater needs up to 3 hours to reach this maximum. All this time the heater consumes full power (minimum - 2 kW). Why not choose a more economical mode by setting the temperature to 50–55 ° С and distributing the consumption in such a way that not all the needs are enough?
Note. Practice shows that the family often does not use all the heated water. That is, after the adoption of hygiene procedures and cooking, the temperature in the heater tank remains quite high, after which the water cools naturally. Such use cannot be called economical.
Scheduled heater on
For the sake of economy, many families who consume water in the morning for washing, and in the evening for the rest of the procedures and cooking, use a simple method: they turn off the unit before going to work and turn it on when they return home. This strategy justifies itself when the tank capacity does not exceed 50 liters - the device heats up for 1-1.5 hours.
It is pointless to turn off water heaters of 80 and 100 liters for the whole day. Firstly, after cooling, they warm up for a long time, and secondly, they consume more energy than was saved. Hence the conclusion: it is better to set the large boiler to the minimum temperature and leave it to work in standby mode. When an increase in water intake is expected, turn the knob to the maximum and after about an hour, get the right amount of hot water.
Tip. There is an option suitable for units of any capacity. Get a simple timer that will turn on heating twice a day at a given time. By the way, in more expensive water heaters the programming function for working on schedule has already been implemented.
Preheating
As mentioned above, in winter, water in centralized networks is often cooled to 10, or even 6 ° C. It is clear that for its heating it is necessary to spend much more electricity. To reduce consumption, you can preheat the water using other sources whose heat is cheaper. Here are a few options:
- Initially, purchase a boiler designed for connection to two energy sources - electricity and hot water from another source, for example, a wood or gas boiler. Such a device, shown in the photo, is equipped with a spiral water heat exchanger.
- Preheat 50-100 liters of water in an iron tank to room temperature, putting such a drive in the hottest room - a boiler house of a private house. For 8-10 hours, while you and the household are at work, the capacity will warm up at 10 ° C in a natural way.
- Finally, use solar collectors - both factory-made and home-made. The method works well in the summer, if desired, an additional tank can be placed on the street, as described in the following video:
Reference. Home craftsmen - craftsmen of the southern regions have long adapted to make solar collectors from black polyethylene pipes placed in the courtyard or on the roof of the house. Thanks to this, the water heater does not actually work and does not “wind up” the electric meter.
Savings on unit cleaning
Over time, calcareous deposits appear on the inner surface of the tank and the tubes of the heating element. The harder the water in the region, the faster they grow. If the material of the tank does not cause tangible damage, then the thickening of the tubular walls of the heating element impairs heat transfer - the water warms up more slowly at a constant energy consumption.
At some point, part of the generated heat does not have time to transfer liquid and additionally heats up the element’s spiral itself, causing the heater to fail. That is why timely cleaning of the water heater is beneficial in all respects.
Note. In the instruction manual for boilers of popular brands (Ariston, Thermex, Electrolux), the frequency of cleaning is not indicated. But there is a requirement for an annual check of the safety valve and once every 2 years - a magnesium anode.
Also, the scheme with the recirculation of hot water is not conducive to saving. Its implementation increases the usability of the boiler, but causes an increase in the consumption of electricity spent by the heater to maintain the temperature in the circulation ring. Such systems are not customary to connect to electrical appliances, for this there are indirect-heating boilers that use cheaper heat.
Conclusion
In the end, we’ll give a couple more tips on how to save energy by using a water heater. The first thing to do is to insulate all the pipelines of the internal DHW distribution in the house or apartment so that they do not give off heat to the premises. The second advice is banal, but does not lose its relevance: take care of the water and do not pour it in vain.
At the same time, saving should not affect your health. Legionella, a harmful bacteria for humans, lives and propagates in warm, stagnant water. So, for prevention purposes, once a week, turn on the boiler to the maximum mode and wait at least 2 hours to get rid of these microorganisms.