What is a coil source?

Coil source (Domestic Hot Water Generator) which is abbreviated as DHWG in facility maps and tables. This resource is used to provide hot water for buildings and various industries. The proper temperature of the spa required for sanitary purposes and washing is between 50 and 60 degrees Celsius.

In order to increase the temperature of the cold water entering from the piping system to the appropriate temperature mentioned, there are various methods. One of the most appropriate methods is to use coil sources.

The coil source consists of a tank with a coil and the cold water is heated by being in indirect proximity to the hot water of the boiler. So, in short, the coil source is a tank for preparing and storing the spa. These sources are made in two horizontal and vertical modes.

 

As can be seen in the figure, the heating water from the boiler enters the thermal coil and after exchanging heat with the water in the tank, it leaves the coil towards the boiler. With this function, there will always be a certain amount of reserve hot water, which is one of the The positive points are the coil source.

If the spa is not used, the hot water of the pipes is returned to the tank to prevent the water in the pipes from cooling, and the hot water is always ready for the consumer. (If the hot water return line is not installed, when the consumer needs the hot water due to the cooling of the water in the pipes, it is necessary to drain all the water so that the hot water reaches the consumer, which causes a waste of water and time. will be.)

In coil sources, the two parameters of the source volume and the heat exchange rate of the coil are of great importance. In general, in order to always have enough sanitary spa depending on the amount and type of consumption, the volume of the source must be calculated correctly. In some cases, the consumption of the spa is not uniform and in some hours of the day and night the consumption is high and in some times the consumption is low. In these cases, when the demand for the spa is not uniform, a coil source with a larger tank volume is used so that the required water is available during peak consumption hours. In some cases, the consumption is even, but the flow rate of the spa is high. In these cases, the heat capacity of the coil should be high so that it can provide the necessary heat for heating the required spa flow. In these cases, the thermal capacity increases with the increase of the coil surface. (In some projects, due to the limited space in the engine room, it is not possible to use coil sources with the required tank volume, in this case, the source volume decreases and the coil surface increases.)