What is Geothermal Heating?

Geothermal heating is called low-temperature floor radiant heating, or floor heating for short. It uses hot water not higher than 60 ° C as a heating medium to circulate in a heating tube to heat the floor and provide indoor heating through radiation and convection through the floor. the way. As early as the 1970s, low-temperature floor radiant heating technology developed rapidly in Europe, America, Korea, and Japan. After time and use verification, low-temperature floor radiant heating saves energy, mature technology, and high thermal efficiency. A heating method for health.

Geothermal heating

(1) Concrete layer: reinforced concrete floor.

(2) Heat reflection layer: Non-woven fabric-based aluminum foil material, which has functions of one-way heat transfer, heat preservation and waterproof.

(3) Insulation layer: generally requires YX foam with a thickness of not less than 30 mm

Is it better to have more geothermal system circuits?

Article 3.6.1 of the National Geothermal Standard mentions that the water inlet and outlet of each loop heating pipe should be connected to the sub-collector and the water collector, respectively. The diameter of the manifold and the collector should not be less than the diameter of the total water supply and return pipe, and the maximum cross-section flow velocity of the manifold and the collector should not be greater than 0.8m / s. Each branch and water collector branch loop should not be more than 8 roads.

Most home owners' home heating pipelines are 1 inch or 6 points, the pressure is about 3 kg, and the pressure difference ranges from 0.05 to 0.2 kg (the system mainly relies on this pressure difference to circulate). The more circuits, the more water volume and pressure difference are needed to ensure the circulation of the system. When the pressure difference and water flow are constant, the more the circuit is, the worse the cycle is.

How much weight can a geothermal system bear?

The floor load of the geothermal system is 2 tons / square meter. (Referring to the data of design and construction in accordance with national standards)

How to choose ground material for geothermal?

The choice of ground material for a geothermal system is very important and can also determine the indoor temperature. There are roughly several options to choose from:

I. High temperature type:

The floor tiles are all used in the room. The thermal resistance of the floor tiles is very small and the heat dissipation effect is the best. The disadvantage is that the room is cooler one month before and after heating. If the heating is normal, the indoor temperature can reach 28-32 degrees;

The floor tiles are used in the kitchen and bathroom, and the Korean floor (high-grade floor leather) is used in other rooms. The temperature can also achieve the effect of floor tiles!

Second, the common type: living room, kitchen, bathroom with floor tiles, bedrooms with floors. Such as heating a normal room, the internal temperature can reach 26-28 degrees;

When heating in winter, the geothermal floor must be able to withstand the high-temperature "baked test". The most basic requirement is that there must not be any cracking and deformation. In non-heating seasons, the geothermal floor must be able to withstand various moisture, especially in the Yangtze River Delta region. In the yellow plum season, in extremely humid environments, the geothermal floor cannot be over-expanded to deform.

Geothermal flooring is generally divided into three categories: reinforced geothermal flooring, solid wood composite geothermal flooring, and solid wood geothermal flooring. These three types of geothermal flooring are suitable for geothermal heating. The technical indicators of stability are required. Industry requirements standards:

1. Heat-resistant dimensional stability (shrinkage rate) standard. The length shrinkage rate of solid wood composite geothermal flooring must be 0.3%, and the width shrinkage rate must be within 0.4%.

2. Moisture resistance dimensional stability (expansion rate) standard. The length shrinkage rate of solid wood composite geothermal flooring must be 0.2% and the width shrinkage rate must be within 0.3%. The length shrinkage rate of reinforced geothermal flooring must be within 0.4% and the width shrinkage rate must be within 0.4%;

The stability of moisture and heat resistance of solid wood geothermal flooring is based on the performance requirements of solid wood composite flooring. The stability performance index of the geothermal floor meets the requirements within the standard range. It is hoped that any geothermal flooring, including solid wood geothermal flooring, is stable to no change. It is impossible and meaningless. At the expense of carbonization and tempering of the natural good properties of wood, the original intention of using solid wood geothermal flooring has been lost. Change, even steel. The shrinkage and swelling of solid wood flooring is its natural property, and it is also the reason why people love solid wood flooring and solid wood complex. The dry shrinkage and swelling characteristics of solid wood floor play a role in regulating indoor humidity. When dry, he will release his own water to make the indoor environment less dry. When wet, he will absorb excess water to make the indoor environment less humid.

How much is the space between the floor heating pipes?

The space between the floor heating pipes depends on the heating conditions and the room layout. The design range is between 100MM-300MM. Taking Shenyang as an example, the general pipe spacing is around 200MM.

First, it meets the comfort requirements of human physiological heating, so that people can feel warmer and more comfortable if the warmth starts from their feet;

2. Save the indoor area and space, save the space occupied by installing radiators and heating pipes, and increase the use area by 2% to 3%;

Third, it can make the indoor heating temperature uniform. After the floor heating is adopted, the room temperature is evenly distributed from the bottom to the top, the air convection is weakened, and the water dispersion loss is reduced.

Fourth, the choice of heat sources is relatively wide, you can use underground hot water, industrial waste heat, heating pipe network, household heating sources, etc .;

5. Energy saving and saving money. Compared with other heating methods, geothermal radiant heating can save energy by about 20%. If a district temperature control device is used, the energy saving can reach 40%;

6. Increase the thickness of the ground, and the aerated (foam) concrete has good sound absorption, so it has a good floor sound insulation effect.

7. There is also a disadvantage of underfloor heating. The northern region is dry in winter and has large outdoor dust. People return to indoors after engaging in outdoor activities. The dust attached to clothing will always suspend in the indoor height range of 1m to 1.2m due to thermal effects. The air causes pollution, especially for children.

Geothermal heating is harmless to the human body ^[1]

Nowadays, many new communities have adopted geothermal heating methods, which can not only save indoor space, beautify the home environment, but also achieve a good heating effect. However, a recent article entitled "Six Major Harms of Underground Heating to the Human Body" has spread widely on the Internet, and it seems that geothermal heating no longer looks so good. In this regard, experts said that floor heating is not harmful to the human body, so don't worry.

Internet rumors say that geothermal heating has six major hazards, such as causing children to develop leukemia, inducing cancer, affecting the reproductive system, causing children's intellectual disability, affecting cardiovascular health, and reducing vision due to heat radiation. The main argument is "radiation-induced disease".

In this regard, Professor Tao Wenzhen, an academician of the Chinese Academy of Sciences and the School of Energy and Power Engineering of Xi'an Jiaotong University, clearly stated in the book "Heat Transfer" that objects in nature emit thermal radiation to space, while continuously absorbing the thermal radiation from other objects. In this way, there is heat transfer between objects. Therefore, heat radiation itself will not cause harm to the human body.

Specifically, geothermal is actually laying a heat medium evenly on the floor.Water and floor heating is to inject hot water into a heating pipe to make it circulate to heat the entire floor.The principle is the same as that of a radiator, but it is transferred to the ground and does not affect the human body. Cause any harm. Although electric geothermal will generate some electric and magnetic fields, but because it is a low-frequency power source and is protected by an insulating layer, the radiation produced is lower than that of an electric blanket, so you don't need to worry about it.

Since geothermal does not cause radiation harm to the human body, why do some people feel uncomfortable in geothermal rooms? Experts said that this has a lot to do with interior decoration materials. "Opening a floor-heated house is equivalent to 'forcing' indoor toxic gases to accelerate the volatilization of formaldehyde and radon. But after a period of time, there is less toxic gas remaining in the floor. From this On the other hand, underfloor heating can also be regarded as accelerating the "driving away" of toxic gases. "Chen Liping, associate professor of the School of Urban Construction and Safety Engineering of Nanjing University of Technology, reminded that when choosing home improvement materials, we must pay attention to choosing environmentally friendly products. In addition, the northern region is very dry in winter, and the outdoor dust is large. People return to indoors after engaging in outdoor activities. Due to the heat of geothermal heat, the dust on the clothing will always be suspended at a height of about 1 meter indoors, causing pollution to indoor air. Therefore, we should pay attention to regulating the humidity of the room and keep it at about 50% ^[1] .