Сombined Water Heaters
In order to buy that combined water heater, which you really need, beforehand it’s important to find all the necessary practical information about it, including advantages and disadvantages of this type.
General information: design and principle of operation
Combined water heater models include the features of indirect and direct heating water heaters:
As usual, an indirect water heating system is connected to another heating technology, for example, to a solid fuel boiler or a heat pump. With the help of heat exchange, in which the coolant circulates, is heated the liquid. Telling in the other words, in the system there is no own source of heat.
Direct heating devices are characterized by the fact, that in their construction there is dry heating element, i.e. electric heater. The task of the heating element is the direct production of heat, transferred to water.
In combined water heaters there is a dry heating element and a heat exchanger. In cold winter days active is the last one, and it is connected to the heating circuit. Supply heat heats the water inside the storage tank, and saves a lot of electricity, because it is consumed only by the main heating equipment. In warm days, when the heating is already turned off, dry heating element is responsible for heating the fluid.
Combined water heaters are especially recommended in the following cases:
- for installation in industrial buildings;
- for installation in private cottages;
- for operation on any objects in the conditions when it’s not possible to use communication routes of gas supply.
Manufacturers offer a wide range of models, different in cost, size, specifications and other indicators. Therefore, you can choose the right option literally for any occasion.
Peculiarities and criteria of choice
One of the most important moments is the material, used for the production of the storage tank. We advise you to give preference to the options with brass cisterns. From the point of view of durability and strength the second place goes to the stainless steel tanks.
Important technical features:
Type of auto control panel. With the help of it can be save resources and controlled the temperature of water;
The quality of thermal insulation. The thicker and better the insulation is, the more economical is the equipment itself;
It shows the boiler’s productivity.
Be attentive! Combined models can be expensive in operation, if you are going to connect them to the electric boiler.
Pay attention on the number of heater coils. If there are two or more of them, then you can connect the equipment simultaneously to several sources of energy, such as a solar battery and a boiler.
Water heaters have a lot of advantages, however, there are also some typical disadvantages. Let’s have a look at the most significant of them.
Let’s look at the advantages of combined water heaters:
- Let’s start with the versatility of technology. In summer time the device will act as a direct heating water heater, and in the winter cold time as an indirect heating device. This is one of the main advantages of it;
- The equipment is able to operate with all your sources of energy, from gas to electricity. Moreover, you can make it work with the source of renewable energy, for example, connecting to a solar collector;
- Combined water heaters are able to provide the required amount of heated water to several points of water intake. For example, if you buy tankless water heater, then it will not be able to deal with such task. The main thing in the case of the combined equipment is to correctly calculate your needs, and, depending on this, determine the appropriate power / performance and capacity of it;
- In case of use of several water access points at the same time, the temperature of the liquid will be balanced;
- You don’t need to connect equipment to the central highway. Installation can be done quickly and easily by your own hands. Note down, that if the installation will be dome with errors that will lead to device failure, and you will lose the warranty from the manufacturer.
Combined water heaters are considered to be reliable and durable equipment that is simple and economical in use. Any model is equipped with several safety and protection systems, which make it a rather good solution for those families, which pay huge attention to the safety of use of the device. For example, families with small kids should pay attention on this variant.
What are the disadvantages of the combined water heating systems?
Now let’s talk about disadvantages of the combined equipment, which should be taken into consideration before buying. These tips will help to make the right choice:
- Will be required an installation of additional devices, for example, a circular pump, a hydraulic needle, a three-way valve;
- In case if you buy a water heater with a large tank, then it will take a long time to heat the liquid;
As usual, combined boilers need constant power supply;
- Even before you buy the device, you will need to determine the suitable strapping system, taking into account specific operating conditions, and make highly accurate engineering calculations;
- Combined water heaters are also dependent on the power of the heating equipment;
- In comparison to tankless models and gas columns, the devices have impressive dimensions. To install them, you will need to allocate a special place;
- The cost of high-quality and functional models is quite high. Including, if we take into account the rates for other types of water heating equipment. The quality and functionality of budget options may be not so high;
- Let’s highlight again, that for the operation of combined heaters, it will be necessary to install an energy source to produce heat, such as a solar collector, a heat pump, or, for example, a boiler. If it is not available, then you will have to nuy more expencive variant.
And finally it should be noted down, that the combined boiler will be the best choice in case if your water consumption is over one and a half liters per minute. Let’s say, that you need to provide hot water for a whole cottage for a family of 3-4 people. Before buying, you need to get an expert advice.