전기변색 코팅이 효율적인 HVAC 달성에 핵심이 될 수 있다

HVAC 에너지 사용 해결

HVAC, 즉 난방·환기·공조는 전 세계 에너지 사용의 주요 부분을 차지하며, 여름에는 건물을 냉각하고 겨울에는 난방합니다. 미국 에너지정보청(EIA)에 따르면 HVAC는 상업용 건물 전체 에너지 소비의 약 40%와 주거용 건물의 35%를 차지합니다.

건물을 냉난방하는 방식을 개선하기 위해 많은 노력이 이루어졌습니다. 특히 핵심적인 방법은 열펌프의 도입으로, 기존 시스템보다 훨씬 효율적으로 열을 건물 안팎으로 이동시킵니다. 열펌프는 전통적인 난방기보다 2~4배 효율적이며 냉방에도 사용할 수 있습니다.

열펌프에 대한 자세한 내용은 “왜 열펌프가 가정용 기후 제어의 최우수 옵션으로 꼽히는가?”를 참고하세요.

열펌프는 시간이 지나면서 더욱 개선될 가능성이 있습니다. 현재는 주로 압축 방식을 이용해 열을 이동시키지만, 곧 전기열성 물질이 열펌프 효율을 더욱 향상시킬 수 있습니다.

하지만 냉난방 에너지 비용을 줄이는 또 다른 방법은 처음부터 열 손실을 개선하는 것입니다. 단열이 부족한 주택이나 사무실은 HVAC 시스템이 외부와 무의미하게 열을 주고받게 됩니다.

우수한 단열은 첫 번째 단계이며 보통 초기 건축 설계에 포함되거나 비용이 많이 드는 리모델링·재건축이 필요합니다. 그러나 단열만으로는 한계가 있으며, 새로운 소재가 도움이 될 수 있습니다.

For example, 적응형 지붕 타일이 온도에 따라 난방 상태와 냉방 상태를 전환할 수 있습니다.

적응형 단열

One limitation of using insulation or automated reactive materials like adaptive roof tiles is that they might sometimes be counterproductive. Ideally, we would prefer to have materials that can be turned on or off at will, modulating the amount of energy entering or exiting the building.

This is especially true for the glass used in windows. In winter, we want as much light and energy entering the building as possible. But in summer, we want to limit the energy warming the building and forcing the air conditioning to work twice as hard.

From this idea came the concept of electrochromic films, a thin layer of material able to turn on the shading of the windows at will. When submitted to a very small electric current, these films can turn from transparent to colored and adsorb heat from infrared radiations.

The technology relies on 금속-유기 골격체(MOFs), 90% 이상 높은 다공성을 가진 소재.

The problem is that until now, typical MOF films have suffered from slow response times and poor stability. This made them promising in theory but not very useful in practice.

This might have changed thanks to a new MOF design invented by researchers at the Harbin Institute of Technology, Quzhou University, Chengdu University of Electronic Science and Technology, and Yangzhou University in China.

전동형 차양

The electrochromic film developed by the researchers works by integrating a new type of MOF. Or, more precisely, “modifying F-doped SnO2 with 4-mercaptobenzoic acid and fabricating Ni-IRMOF-74@MBA films using 3,3′-dihydroxy-4,4′-biphenyldicarboxylic acid”.

Because of the crystalline substances’ ability to form thin films with pore sizes that can be customized by changing the length of the organic ligand that binds to the metal ion. These features enable improved current flow, more precise control over colors, and durability.

The result is a film that can change color to green when exposed to 0.8V and dark red/brown with 1.6V.

출처: ACS

The film is remarkable from other previous MOFs due to its stability (95.7% retention after 4500 cycles) and a rapid response below 2 seconds.

It is not clear yet how widespread such system adoption might be. But overall, because of the need to decarbonize and reduce energy consumption, it is one more arrow in the quiver of turning cities greener.

박막 기업

1. China Singyes New Materials Holdings Limited (8073.HK)

The Chinese company entered the field of optical thin film materials in 2010. It produces multimedia commercial display systems and creates intelligent dimming projection systems, multimedia transparent photoelectric glass, etc.

This includes glass walls that can be turned opaque as well as heat-resistant smart film. So, it could be a good candidate for deploying electrochromic glass as well.

출처: China Singyes

The company published its financial reports in English, not always something guaranteed for smaller or niche Chinese industrial companies.

The company has been expanding in 2023 into the production of motor vehicle films, a booming sector following the growth of the Chinese automotive industry and Chinese car exports (mostly of EVs).

Overall, the company is innovative and will likely benefit from the overall Chinese economic performance and the growing demand for more advanced materials to display advertisements and offer privacy in interior spaces like hotels and offices.

2. Kewei Films

A privately listed company, Kewei is the “biggest ITO PET, smart film, window film manufacturer”, with 60 million meters of annual production capacity.

This makes it China’s biggest window tint, paint protection film, car wrap vinyl film, and smart film producer.

Its window films are already used to reduce cooling costs. It also produced smart glass, with opacity that can be turned on at will.

출처: Kewei

Considering the scale of Kewei, investors in the smart film sector should keep an eye on the company even if it’s not publicly traded. This is especially true if new forms of electrochromic coatings are created that can grow the market and give an advantage to large established players in leveraging their size to cut production costs.

electrochromic 코팅이 시장을 확대하고 규모가 큰 기존 기업이 생산 비용을 절감할 수 있는 이점을 제공하도록 만들어질 수 있습니다.