What is the return water system? Is it necessary to install a backwater system during home renovation?

When a friend’s house was renovated, the decoration company asked him to install hot water return pipes. He also said that this is the current "standard" for decoration. Many finely decorated houses do this. The advantage is that it can achieve "zero cold water" in the whole house. , more convenient when using hot water.

Later, a friend asked me for my opinion. After hearing this, I could only lament that there are so many ways for decoration companies to make money nowadays. Has the hot water return pipe become the "standard" for decoration?

I don’t quite agree with this. What exactly is a hot water return pipe? When renovating your home, is it necessary to install a hot water circulation system? Today we will talk about this topic in detail.

Usually, the hot water used in our homes is heated by water heaters, and then flows through water pipes to other water points, such as faucets, showers, etc. Therefore, the flow direction of water is very simple and fixed, tap water - cold water inlet - hot water outlet - drainage system. When we decorate and arrange water and electricity, we must take this into consideration. This is also the basis for laying water pipes.

Looking at it this way, there seems to be no problem, but there will be these shortcomings in use: every time you open the faucet and want to use hot water, what comes out first is the residual water in the water pipe. of cold water, in other words, the cold water must be drained in order to have hot water. Not only is water wasted, it also affects the user experience.

If we want to achieve "zero cold water" and have hot water in the hot water pipes at all times, then we must establish a hot water circulation system during decoration. As the name suggests, the hot water circulation system circulates hot water. Every once in a while, the hot water can be returned to the water heater for reheating.

The hot water return pipe is actually a special pipe added to the cold water pipe and hot water pipe. The hot water can return to the water heater through this pipe.

The hot water circulation system can be simply understood as adding a hot water return pipe to the original water pipe, so that the water flow is no longer fixed.

However, the key to the hot water circulation system is not the return pipe, but the hot water circulation pump. Because the hot water return pipe only provides a way for hot water to return. In addition to flowing in the hot water pipe, hot water can also flow through other pipes. What really provides power for hot water return is the hot water circulation pump, which is This small box is pictured below:

When the hot water circulation pump works, it pressurizes the pipes to promote water flow and circulation.

From the above circulation system, the hot water return pipe and hot water circulation pump are the most important system components. It seems that it is necessary to install the hot water return pipe. But this is not the case, because many water heaters now have the function of hot water circulation pumps, which can directly use the cold water pipe as a return pipe.

On the other hand, hot water circulation pumps are also divided into categories. One type requires a hot water return pipe, and the other does not require a hot water return pipe.

A circulating pump that requires a hot water return pipe is the same as mentioned above. The water in the hot water pipe is pressurized by the circulating pump, and then returns to the water heater through a special pipe such as a hot water return pipe. in. If you want to establish such a hot water circulation system, it means that the hot water return pipe must be arranged in advance during decoration.

There is no need for a circulation pump for the hot water return pipe. Just add a one-way valve between the hot water pipe and the cold water pipe to connect the hot water pipe and the cold water pipe together and let the cold water pipe serve as the hot water return pipe. The role of water pipes. Essentially, this is the same principle as a gas water heater with its own hot water circulation pump, except that one relies on the circulation pump inside the water heater and the other relies on an external hot water circulation pump.

Do I need to install a hot water return pipe? If the hot water return pipe is not installed, there will be such disadvantages during use: the cold water pipe and the hot water pipe must be in the same pipe, the cold water is easily contaminated, and more cold water may be mixed into the circulation, affecting the circulation effect. , resulting in increased power consumption (gas volume).

Therefore, the most ideal state of the hot water circulation system is to install the hot water return pipe and the hot water circulation pump at the same time, but even if there is no hot water return pipe, it is still possible, just use another method Just do hot water circulation.

The hot water return pipe is not necessary, but it would be better to match the hot water circulation pump with the hot water return pipe.

So let’s return to the original question, is it necessary to install a hot water circulation system?

I think it needs to be discussed on a case-by-case basis. First of all, the first case is to consider the size of the home. If the area of ??the home is too large, it means that the distance between the water heater and the water point is relatively long, and the water pipe is too long, which means that every time the hot water is used up, there will be more residual water, and it will take a long time for the water to heat up every time. Water will also waste cold water. In this case, it is more recommended to install a hot water circulation system.

If your home is not large and the water heater is relatively close to the water point, the time you have to wait for hot water is actually not long. The waste of cold water is very limited, and you need to lay a return pipe and purchase a hot water circulation system. The price of the pump is enough to cover hundreds of tons of water bills.

Another situation is to consider it based on your own economic conditions. Although there is hot water when you turn on the faucet, there is no need to waste cold water, and the "zero cold water" experience is very good, but the hot water circulation system consumes a lot of electricity. The larger the applicable area of ??the hot water circulation pump on the market, the greater the power. If turned on 24 hours a day, it may require 2-3 kWh of electricity.