Which water heater is better - instantaneous or storage? Comparative review
Do you want to ensure your independence from the warm water supply schedule by installing a heating device? But you don’t know which water heater is better - instantaneous or storage, and which model will be optimal for your home? This important issue is worth dealing with, don’t you agree?
We will help you understand the choice of equipment. The article we propose examines the characteristics and design features of storage and flow models. Their main advantages and operational nuances are highlighted.
Comparing these two types of water heaters and understanding the intricacies of determining which option is best for your individual needs will help you make an informed purchase. The presented material is supplemented with photographs and video reviews of storage and flow models, and valuable recommendations.
The content of the article:
Operating principle of instantaneous water heaters
The name of these devices speaks for itself - they heat up the water immediately when turned on and supply it to the water collection point already warm, without bulky storage tanks.
The energy source can be a heating element or a gas burner; solid fuel units are less common.
Design features of electrical appliances
Such heaters are divided into non-pressure and pressure. The first ones are designed for use on one tap (usually immediately equipped with a shower head or spout), the level of internal pressure here is equal to atmospheric pressure.
Pressure systems are powerful systems that can supply hot water to several water supply points at once, thanks to the high pressure in the water supply network.
The heating container is small in size, inside of which there is a heating element or a non-insulated coil for heating cold water. In a closed system, the heating elements do not directly come into contact with water, the flow passes through a copper or brass tube, so this heater does not have problems with scale and the need for regular cleaning.
Appliances with an open spiral consume 15-20% more energy, but also heat water much more efficiently.
But since their heating element is located in the water, it is advisable to install a filter system at the inlet. Although the manufacturers claim that the device is designed so that during operation it creates vibrations that do not allow scale to settle on the spiral.
For safe operation, all devices are equipped with sensors that monitor the heating temperature, flow rate and, if necessary, stop the operation of the heating elements.
You can regulate the temperature of the water supply using a tap, increasing or decreasing the pressure. Most models are equipped with a mechanical switch, but there are also devices with the ability to program the temperature on the control unit.
Gas water heaters and their nuances
Although electric models of heaters are increasingly conquering the market, the “pioneers” of hot water supply are no less successfully operated - geysers. In these devices, cold water flows through a winding coil and is heated by a burner flame.
But installing gas heaters has a number of nuances. To install them, it is necessary to obtain special permission from gas workers, equip the room with good ventilation and a chimney where air with combustion products will be discharged.
In addition, for the column to operate, you need a stable water pressure, with a pressure of at least 0.25 atmospheres, otherwise the unit simply will not turn on.
Therefore, it is possible to easily install (or rather, replace) a gas water heater only in houses whose design already included this equipment. And in new buildings it is better to give preference to safer ones electrical appliances, the installation of which is permissible in high-rise buildings.
Pros and cons of flow heating
Devices that directly heat the stream are able to provide an unlimited supply of warm water without preheating or long wait times.
Other benefits:
- Compact models do not take up much space and can be hidden behind furniture facades or installed next to the sink to minimize heat loss.
- They do not consume energy when the tap is turned off, unlike boilers.
- Instantly heats water to 35-60 degrees (depending on the power of the model and the temperature of the cold flow).
- They cost several times less than storage units.
The disadvantages include the low pressure of the hot flow in low-power devices, because the water must have time to warm up while passing through the thin tube of the heat exchanger.
Also, electric heaters are demanding in terms of wiring power; if you install a flow-through system to supply the entire house or several points, you will need a 380 V line; a regular 220 V will not work.
And another significant disadvantage concerns inexpensive devices with a fixed heating power - in cold and warm seasons, the water temperature can vary by up to 20 degrees (and this is with the same pressure). That is, in hot weather, the water in the tap can reach 50 °C, and in winter you will have to take a shower at an invigorating 30-40 °C.
Features of storage boiler
The device itself is a capacious, thermally insulated tank with pipes for supplying cold water and discharging hot water. Inside the container there is a 1-2 kW heating element, a temperature sensor and a magnesium anode that protects the device from scale.
There is another type of storage devices - indirect heating boilers, where the role of the heating element is played by a coil heat exchanger connected to the heating circuit.
But this option is often chosen in addition to a single-circuit heating boiler to save energy resources in the cold season, and in the summer it works on the same principle electric boiler (of course, provided that the package includes a heating element).
When turned on, the boiler draws water and heats it to the programmed temperature (for example, it will take about 2 hours to heat 100 liters with a 2 kW heating element to 60 degrees). When the water heats up, the thermostat activates and turns off the heating element.
Advantages of boilers:
- The connection does not require a powerful power line; even at standard 220 V, the device will easily service several mixers at the same time.
- The ability to maintain the temperature of the water in the container for a long time (if there is a high-quality thermal insulation casing, the heating level will decrease by no more than 1-2 °C per hour).
- They are capable of immediately “dispensing” a large amount of water, for example, to quickly fill a bathtub.
- The temperature of the supplied water is always the same and will not depend on the time of year.
And the main disadvantages of a storage heater include a limited limit of hot water, a long waiting time for heating “from scratch” and the impressive dimensions of the tank (moreover, the greater the family’s needs, the more cumbersome the device will be).
It should also be taken into account that if the device is not disconnected from the network, it will consume energy even in standby mode, heating the water to the specified parameters when cooling.
Comparison of water heating devices
Flow and heating devices vary in size, price, appearance and energy consumption. Let's look at the most significant differences.
Parameter #1 - weight and dimensions of units
In this category, the winners will undoubtedly be continuous heating devices - they weigh no more than 2 kg and are compact in size. For example, to connect to a shower, a device 30 cm wide, 15-18 cm high and 10-11 cm thick is sufficient, which will not take up much space even in a standard stall.
Although there are storage boilers the size of a football, their capacity is only 5-10 liters, which is clearly not enough even for the needs of one person.
Therefore, you will have to find a place for a round or rectangular unit measuring at least 55x50x40 cm (and this is for a container of only 50 liters). Moreover, devices with a volume of up to 120 liters are suitable for wall mounting, and larger models are designed for installation on the floor.
Parameter #2 - volume of the internal tank
The main criterion for the performance of a boiler is the volume of its internal tank, and the power of the heating element in factory products is already “tied” to the size of the tank. Therefore, the size of the drive is selected solely according to the needs of the family.
You can determine the required performance for an electric flow-through heater by the flow rate - the lower the power of the device, the thinner the stream of hot water will be.
The recommended speed of water movement in pipes can be studied in SNiPe 2.04.02-84, and calculate the comfort level yourself by placing a bucket under the shower head or tap and measuring the amount of water that flows out per minute.
Calculate productivity using the following formula:
V=14.3*(W/T2 -T1),
Where:
- V – maximum flow rate;
- W – heater power in kW;
- T2 – set water heating temperature;
- T1 – water temperature in the water supply - for winter it is about 0 °C, for summer +15 °C, but it all depends on the climatic characteristics of your area.
But it’s easier to trust the manufacturers’ recommendations by studying the instructions. It should indicate the scope of application of the product and how many liters the device can heat in 1 minute.
To set up water collection points that do not require a large volume of water for a one-time use, it is better to give preference to electric flowers, the range of which includes models for shower cabins And for mixers over the sink.
On average, for a shower you will need a heater of 5-8 kW, for a faucet in the kitchen or a sink in the bathroom 3-3.5 kW will be enough, and to supply several water points at once - from 12 kW or more.
Parameter #3 - efficiency and resource consumption
Many consumers do not even consider instantaneous heaters due to the high energy consumption.
But this is not entirely correct. If you recall at least a school physics course, it becomes clear that heating one liter of water will require the same amount of energy, and it does not matter what kind of device will heat it, flow-through or storage.
Therefore, the energy consumption will be higher electric boiler, because it spends resources not only on heating water, but also on maintaining its temperature.For example, a device with polyurethane foam insulation 4-5 cm thick will consume 1-2 kWh for cooling protection.
A flow-through heater is more demanding on network power, but it consumes exactly as much electricity as is needed to supply the required amount of water.
As for the cost of heating devices, the price of boilers is 2-3 times higher than the cost of purchasing a flow-through unit, although, of course, much depends on the model and its power. And in terms of prevention, flow-through systems have less impact on the budget - when installing a filter at the inlet, you will have to look inside the device no more than once in a couple of years of operation.
Caring for the boiler requires regular cleaning of limestone from both the heating element itself and the inner walls of the tank and timely replacement of the magnesium anode rod.
If you neglect these recommendations, the device will constantly increase the heating time and spend more and more energy, and over time it will fail. But even with good care, devices rarely “survive” more than 10 years, but flow-through heaters easily pass this mark.
Parameter #4 - installation and connection features
Installing a simple instantaneous water heater is quite simple, even if the renovation of the apartment is already behind you. The device has special fastenings, which make it easy to hang it on a wall (even plasterboard), like any wall cabinet. Using a flexible hose, the inlet to the water supply system is connected, and the hot water outlet is connected to the mixer.
If we are talking about a powerful device rated at 5 kW or more, it is connected with a separate cable from the panel to a network with a voltage of 380 V.
To attach the boiler to the wall, special anchors (diameter from 10 mm and length from 100 mm) are installed on dowels, on which the device is suspended.
Then pressure is released from the blocked water supply system, shut-off valves and tees are cut into the pipes. To extend the “life” of the heating element, it is additionally recommended to install fine mechanical and deep cleaning filters at the cold water inlet.
The boiler is connected via an RCD to a dedicated outlet with mandatory grounding. After connecting to the network, the activity indicator on the device will light up, after which you can program the temperature mode for heating water and test the operation of the device.
Which water heater should you choose?
Although storage devices are more familiar and popular with consumers, before purchasing a heater it is worth considering all the possibilities based on the number of people in the family, the power of the wiring, the size of the house and its layout.
Several options to consider.
Option 1. If the power of the electrical network allows, you can install a flow-through heating device only on the shower. This way you won’t have to wait several hours for the storage tank to heat up, and there won’t be a situation where the last person in line doesn’t have enough hot water.
And the boiler is useful for filling the bath, washing dishes and other household needs. In addition, such a tandem will allow you to choose a smaller drive and save useful space.
Option #2. Combining heaters makes sense if the kitchen is located far from the bathroom or boiler location. In this case, it is worth considering the possibility of installing a flow-through device on the sink tap.
Moreover, even if the electrical network in the house is standard, a small power device is quite enough for a kitchen faucet.
Option #3. Installing a floor-mounted boiler with a large volume will help solve the problem of hot water supply when it is not possible to install a three-phase cable into the room.
Option #4. For country houses with seasonal attendance it is better install instantaneous water heater – then you won’t have to wait long for warm water, and in this case there is no particular point in accumulating “reserves”.
Option #5. If in a private house there is a gas or solid fuel boiler with one circuit, you can use it connect an indirect heating boiler and save on electricity in winter.
The conclusion suggests itself: for small and irregular consumption, a flow-through device is quite sufficient; for constant consumption, it is better to choose a boiler.
But if the flow rate is high, you can consider combining different types of heaters or installing a high-power flow system connected to a three-phase network.
Details with selection arguments storage water heaters And flow equipment read the articles we recommend, which contain a lot of useful information and recommendations.
Conclusions and useful video on the topic
To conduct a visual comparative analysis of water heating devices, study video materials with recommendations from experts on the selection and installation of equipment.
Video #1. About the design and design options of storage heaters:
Video #2. Direct heating electrical appliances, operating principle and types:
Video #3. Criteria for choosing electric boilers and instantaneous heaters:
As you can see, there is no clear answer to the question of what is better for the home – a storage or flow-through heater, because each device has its own characteristics and nuances.
But if you can’t decide for yourself, consult with plumbers who specialize in installing water heaters and installing plumbing systems. They will tell you which option will be the “golden mean” for your house or apartment.
What type of water heater did you prefer to install in your house/apartment? Tell us what justifies your choice, share your own arguments with site visitors. Please write comments in the block below, ask questions, post photos on the topic of the article.
A few weeks ago, our family faced the issue of moving in with our parents, but since they live in a house without a central water supply, I thought about solving this problem. There is a boiler in the shower, but I want running hot water from the kitchen tap. I’m very used to a city apartment with all the amenities.Alas, there are significant disadvantages for both the storage system and the flow-through system. Therefore, we still have a difficult choice to make, but I will take note of the good options proposed here.
Yes, the storage system has disadvantages, but it is still much better than the flow system. The pressure of the groove is very thin, it is very inconvenient. I had a hard time with her. If there is free space, then it is definitely better to install a storage one.
We have had a gas water heater for 15 years. It's a lot of hassle - it often breaks down, it's quite difficult to turn it on, and if you keep it on all the time, the gas bill comes up. But you can’t switch to electric either, because the lights are often turned off. I myself watched with friends how the lights were turned off in winter, and immediately not only the water stopped heating, but also the radiators began to cool down. I want to buy a water heater that runs on both gas and electricity.
A flow-through heater is only convenient for washing dishes or taking a shower under a thin stream of water at 30-40 degrees. The article is good, but the author didn’t post all the numbers. I have an 80-liter storage boiler hanging and I turn it on at night when electricity costs several times less and here school physics will not help calculate the benefits))) the price of a flow-through liter and a storage one))) only the size is beneficial in flow-through
Hello. So many guns and spears are broken in comparisons. I made my choice by comparing models of a groove and a storage tank with similar power. For the same price, I got half as much water in the flow, this is what happens if you dilute boiler water to flow temperature.
In a large family, in an ordinary house, a boiler is more economical.But, for example, at the dacha, it is better to have a storage one, since there is no need to drain the water when leaving, creating excess oxide, and there is no need to heat the water for a long time; water consumption there is usually minimal.
Also for those who live alone. But the price range is different everywhere, not in all settlements electricity is cheaper at night, in many the price is fixed per day/night.
We are a family of three, but our daughter pours the water herself for the three of us :) The best is the boiler room, because there is always a supply of heated water, even when it’s turned off. To save energy, I set it to 60 degrees. It is not necessary to heat it to 80 and maintain it.