A family's floor heating manifold is broken, and it's quite troublesome to repair.
Issue One
Is installing underfloor heating good or bad?
Mr. Zhu from Golf Garden had underfloor heating installed when he bought his house. "When the house was handed over, there was no water or electricity, so we couldn't test whether the underfloor heating worked. It wasn't until after we moved in that we discovered the underfloor heating was basically unusable." Mr. Zhu then found the warranty card for the underfloor heating system and tried to get the original company to come and fix it. However, after some searching, he found out that the company responsible for his underfloor heating no longer existed. Out of desperation, he contacted another underfloor heating company and asked their maintenance staff to come and inspect. After inspection, they found that the reason his underfloor heating wasn't working was due to a clogged manifold. Following the advice of the maintenance personnel, he spent 200 yuan to replace the manifold. Although the equipment was repaired, after using it several times, he found that while the underfloor heating was comfortable, it wasn't cost-effective: "To keep the underfloor heating warm, you have to leave the boiler on all the time; otherwise, just preheating would take almost a day." In Mr. Zhu's view, normally only he and his wife live at home, and everyone is very busy with little time spent at home, so leaving the boiler on all the time felt like a waste. Consequently, his underfloor heating quickly became a mere decoration and was never used again.
Issue Two
The current state of the Suzhou underfloor heating industry
What kind of maintenance and care do underfloor heating companies provide after collecting maintenance fees? According to an insider in the industry, water-based underfloor heating systems are most prone to issues in three parts: the boiler, the manifold, and the pipes. First, because boilers are generally installed in kitchens, they can accumulate impurities in environments with heavy grease over long periods of time, thus requiring regular cleaning. Simultaneously, the water replenishment valve in the boiler only heats properly when the pressure is maintained within a certain standard. When air enters the replenishment valve, the pressure drops or even disappears, so annual water replenishment and pressurization is necessary to maintain normal boiler operation. Second, the manifold is the heart of the underfloor heating system. If it is exposed to humid air for a long time, the copper filter inside may be damaged, leading to the inability of the underfloor heating system to function. Additionally, impurities in the water easily adhere to the inner walls of the ground pipe coils. If these are not cleaned regularly over long periods, it can lead to pipe blockages.
"For local residents in Suzhou, many make mistakes when using the system," this insider analyzed. One misconception is that people think underfloor heating works like an air conditioner, where they turn off the power when no one is at home and then turn it back on when they return, believing it saves energy. This is not true, as underfloor heating requires five hours of preheating each time, and every time it needs to heat the water to a set temperature, so the energy consumption of running it for five hours is almost the same as running it for 24 hours. Another misconception is that people don't pay enough attention to the maintenance and care of underfloor heating equipment. Many residents believe that installing underfloor heating is a one-time solution and never consider maintenance, which eventually leads to pipe blockages. Since the heating pipes are buried under the floor, once blocked, the equipment becomes useless.
Issue Three
Who will regulate the chaos in the market?
Deputy Secretary-General Yan Xiaoping of the Suzhou Decoration Association stated that underfloor heating is more common in the north but less so in the south. In Suzhou, it has only become a prominent industry in recent years. Due to the complexity of the underfloor heating system, involving multiple fields and spanning multiple industries, it increases the difficulty for relevant departments to regulate it. Therefore, China still lacks a clear regulatory body for this industry. Yan Xiaoping said that in the past two or three years, they have received almost no complaints about underfloor heating. Regarding whether underfloor heating falls under the supervision of the Decoration Association, it also depends on specific circumstances: if the owner specifies underfloor heating during the renovation process and includes it in the overall renovation budget through a contract with the decoration company, then when quality issues arise, the owner can demand accountability from the decoration company or file a complaint with the Decoration Association. On the other hand, if the owner did not specify underfloor heating in the renovation contract but instead signed directly with the underfloor heating supplier, then any quality issues would not fall under the jurisdiction of the Decoration Association, and the owner could file a complaint through the industrial and commercial department. Yan Xiaoping advises citizens to choose professional companies with good reputations in the industry so that even if problems occur, they can receive better maintenance and care.
As of now, the sales volume of thin-type underfloor heating products by my company is merely over 2,000 square meters this year," said a business executive who has been in the industry for many years, speaking helplessly about the development status of thin-type underfloor heating. In fact, companies that perform poorly in the sales of thin-type underfloor heating are not few. Many business executives reported that the sales of thin-type underfloor heating in their respective companies are extremely limited and mostly concentrated in southern regions. This is contrary to the views held by some industry insiders who previously believed that "thin-type underfloor heating has transitioned from the introduction phase to the growth phase and will inevitably enter a period of rapid development, positively impacting the installation of underfloor heating and the entire building market's heating sector."
As previously predicted by industry experts, thinning is a direction of development for China's underfloor heating systems. However, thin-type underfloor heating systems adapted to this trend have not shown the expected positive development momentum. What are the reasons?
Bulk-sold properties dominate, limiting the use of thin-type underfloor heating systems.
Jin Jizong, secretary-general of the Beijing Construction Engineering Material Association's Underfloor Heating Branch, stated: "The current real estate commodity sales model is a significant factor affecting the development of thin-type underfloor heating systems. Actually, thin-type underfloor heating systems are more suitable for fully-furnished residential projects. However, currently, bulk-sold properties dominate the Chinese real estate market. Since thin-type underfloor heating systems mostly use dry-lay installation methods, this causes the pipelines of the underfloor heating system to be exposed on the surface when the property is handed over to the owner, a situation that most owners find hard to accept. Therefore, developers prefer to say 'no' to this new type of underfloor heating product."
Deng Youyuan, head of the expert group of the Radiant Heating and Cooling Committee of the China Building Metal Structure Association, agrees with Jin Jizong's statement. He believes that since this commodity sales model in the real estate market will continue to exist for a long time, the development prospects of thin-type underfloor heating systems remain bleak. If in the future, fully-furnished residential projects can dominate the Chinese real estate market, the development of thin-type underfloor heating systems might see a significant turning point.
High product price positioning leads to low market demand.
Many thin-type underfloor heating manufacturers believe that thin-type underfloor heating systems have obvious advantages over traditional water-based underfloor heating systems in terms of thickness and weight, making them particularly suitable for old building renovations and homes with lower ceiling heights. Therefore, their development prospects are also broad. However, Guo Chunyu, chief engineer of Chongqing Wenxin Era HVAC Equipment Co., Ltd., pointed out that with the continuous emergence of thinner trends in traditional water-based underfloor heating systems, the advantages of thin-type underfloor heating systems are gradually diminishing due to their high prices.
It is understood that many thin-type underfloor heating companies have targeted the high-end market. A thin-type underfloor heating distributor told the reporter that the current market price of thin-type underfloor heating products is generally higher than that of traditional water-based underfloor heating products. This makes many users feel intimidated.
In response, many manufacturers attempt to balance the cost-performance ratio through the product's energy-saving and short construction period advantages. However, some insiders in the industry pointed out that in terms of energy saving, which users are most concerned about, many manufacturers emphasize its fast warming (a layer of metal conductive aluminum plate is laid above the heating pipe, effectively absorbing and conducting heat, allowing the heat in the heating pipe to quickly transfer to the decorative surface), making it more energy-efficient than traditional water-based underfloor heating systems. In reality, similar to the fast warming, the cooling speed of thin-type underfloor heating systems is also fast, and its heat storage capacity is far inferior to that of traditional water-based underfloor heating systems. Therefore, promoting thin-type underfloor heating systems as energy-saving from this perspective clearly does not hold up and is hard to gain public trust.
Moreover, from the perspective of the entire domestic market, the demand for thin-type underfloor heating systems is not large. This is mainly because China's heating needs are currently concentrated in the north, where centralized heating coverage is relatively high, and most newly built buildings are bulk-sold properties.
Limited pressure-bearing capacity and high water quality requirements for some products.
In addition to the aforementioned factors, the limited pressure-bearing capacity of thin-type underfloor heating systems is also a major factor affecting their development. In terms of pressure-bearing capacity, the cement backfill layer of traditional underfloor heating systems is an integral whole, with furniture pressure directly acting on part of the cement backfill layer, which evenly distributes this pressure across the entire backfill layer. Thin-type underfloor heating systems lack a cement backfill layer, so the surface is not an integral whole. As a result, furniture pressure directly acts on part of the insulation layer, and over time, it can easily cause the insulation layer to lose elasticity or deform.
The upcoming national standard, "Pre-cast Lightweight Warm Water Radiant Heating Panels," imposes higher technical requirements in this regard, but before the standard is released, users have many doubts about whether existing thin-type underfloor heating products on the market can meet these standards.
Furthermore, some shortcomings of certain products have caused users to develop a negative impression of the entire thin-type underfloor heating product category. It is understood that thin-type underfloor heating systems are divided into two categories based on the thickness of the insulation layer: those below 20 millimeters and those above 25 millimeters. The former applies to underfloor heating pipes with diameters below 14 millimeters, while the latter applies to conventional underfloor heating pipes with diameters of 16 millimeters and 20 millimeters. Because the former uses thinner accompanying underfloor heating pipes, they are more prone to blockages and require higher water quality.
Therefore, under the water conditions in the north, if such ultra-thin underfloor heating systems are used, it is best to use distilled water and install filters, sewage discharge valves, and exhaust dedicated valves. Even if the water quality issue is resolved, in practical applications, due to the fineness of the pipes, the ultra-thin underfloor heating system may lead to excessive resistance, poor water flow, and poor water circulation throughout the system, resulting in cold underfloor heating pipes.
At the same time, the entire system of this ultra-thin underfloor heating system can only withstand a very limited supply water pressure, generally not exceeding 4 kilograms of water pressure, so it is not suitable for high-rise users.
Insufficient enterprise awareness leads to system issues during use.
Regarding the reasons why the development of thin-type underfloor heating systems is restricted, many people also attribute it to the insufficient understanding of thin-type underfloor heating systems among people. Gu Chunyu pointed out: "Not only do ordinary users lack understanding of thin-type underfloor heating systems, but even many thin-type underfloor heating manufacturers and construction enterprises have insufficient knowledge of the product."
In this regard, Gu Shi'an, chairman of Oriental Green & Cool (Beijing) Cold & Warm Technology Development Co., Ltd., pointed out that from the perspective of heat dissipation capability, the concrete backfill layer of traditional water-based underfloor heating systems evenly wraps around the pipes. Due to the strong heat absorption and dissipation capabilities of concrete, heat exchange occurs on the entire surface of the pipes. However, although some thin-type underfloor heating systems use grooved insulation boards and aluminum foil heat-conducting plates, their heat transfer capabilities are still very poor. A large part of the reason lies in the insufficient understanding of thin-type underfloor heating systems by many manufacturers, and even the aluminum foil they produce is too thin to meet system requirements. Some manufacturers' aluminum foils, although reaching the system requirements in thickness and having good heat transfer results, often produce excessive noise during actual use.
This phenomenon of lacking understanding leading to problems during product use also manifests in the construction aspect. Many construction enterprises have not mastered the dry-laying method well, and their work in leveling the ground is inadequate, which can easily lead to problems with the ground decorations (such as cracked or deformed floors). "Therefore, issuing related standards for thin-type underfloor heating systems is urgent," said Gu Shi'an.