'Those who knock will find the door opens': Dasco Chairman Han Sang-won's 40-year drive into solar energy and noise reduction

"Those who knock will find the door opens."

That has been the guiding belief of Han Sang-won, chairman of Dasco, throughout nearly four decades at the helm. The company started out making guardrails for roads, then expanded into architectural deck plates and insulation boards, and developed smoke vents that clear fumes from soundproof tunnels during fires. More recently, it has moved into floor structures designed to reduce inter-floor noise in apartment buildings and into solar power generation — businesses that, at first glance, seem to have little in common.

Han traces the logic of that expansion to his own upbringing. "I am a self-made entrepreneur who grew up learning and figuring things out on my own," he said in a written interview. "From the very idea of the guardrail, I knew that you cannot make serious money doing what everyone else is already doing, so I have always tried to walk paths others have not."

"I tried countless things, and wherever I found a market and a livelihood amid all that change, I developed the technology and knocked on the door," he added. "It is that belief — that the door opens to those who knock — that led us into so many different fields."

Dasco began with road safety equipment. In the company's early days, Han developed a high-specification guardrail that passed crash-test certification at the Texas Transportation Institute. The company then broadened from road and bridge safety structures into noise barriers, deck plates and insulation boards. Its current portfolio spans SOC infrastructure anchored in road safety equipment, building materials including deck plates, insulation boards and inter-floor noise solutions, and an energy business covering solar and wind power equipment and construction.

Headquartered in Hwasun, South Jeolla Province, Dasco has operated a Seoul office since 1998 to serve the Greater Seoul market. It also runs a manufacturing facility in Dangjin, South Chungcheong Province, for deck plate and insulation board production. "Most of our technical staff work out of the Seoul office," Han said. "The Greater Seoul market is far larger for deck plates and insulation boards, so we operate the manufacturing site in Dangjin — and that creates no real problem for sales in the metropolitan area."

One of the doors Dasco has been knocking on lately is the apartment floor. The company is developing technology to reduce inter-floor noise in multi-unit residential buildings.

"Floor noise between units is a serious social problem in apartment living," Han said. "Our company has long provided noise solutions tied to road tunnel sound barriers — addressing the noise impact on nearby residents. Now we want to develop and spread noise-reduction technology for the floor construction methods used in apartment buildings themselves, and become a company that solves everyday noise problems."

Dasco's approach is to design the floor structure itself, at the construction stage, so that impact sound is reduced in multiple layers before it travels between floors.

"Existing floor dampening products work by laying a separate sponge-like impact-absorbing material on top of an already-finished floor," Han said. "But now the obligation is being placed on developers and contractors from the construction stage itself — applying a floor structure that reduces impact sound in two or three layers within the flooring method."

The technology is nearly ready for commercialization. In May, Dasco received certification from the Korea Land and Housing Corp. for a floor structure rated Grade 1 for lightweight impact sound and Grade 2 for heavyweight impact sound. "You can think of the current stage as preparation for commercialization, just before field application," Han said. "A more affordable, entry-level version of the technology that meets the minimum certification standards while bringing down the cost is also in the final stages of development." Dasco plans to complete mass-production readiness and finish business preparations by early next year, then begin taking orders from the second quarter.

Dasco's technology research institute employs 10 technical staff and four administrative support staff. Annual research spending runs about 1.5 billion won ($1.11 million). "In the very early days of the company, it all started with my own idea to make guardrails safer — to protect the lives of road users," Han said. "When that idea became reality and was installed on roads across the country, performing its role in keeping people safe, I felt a deep sense of pride."

"Human safety" is a phrase Han returns to again and again when describing Dasco's technology. The clearest example is the company's automatic smoke vent for soundproof tunnels — a ceiling-mounted device that opens to expel smoke and heat even when the power supply is cut during a fire.

Han cited the 2022 fire at a soundproof tunnel on the Second Gyeongin Expressway. "Five people died and more than 40 were injured in that major accident, making it painfully clear that fire-safety equipment inside tunnels needed to be expanded," he said. "We pooled ideas from staff across our research institute and business divisions and turned them into reality."

The smoke-exhaust system Han developed uses a pneumatic system driven by compressed air — specifically so the vents can be opened even when a fire cuts the power supply.

"The biggest distinguishing feature is that, unlike the electric smoke vents used in conventional buildings, we applied a compressed-air pneumatic system optimized for the road soundproof tunnel environment," Han said. "Whether the power supply is cut or any other disaster occurs, the windows open immediately, securing the evacuation safety of people inside the tunnel and the performance of fire-suppression measures."

The system has passed more than 10 verification tests and certifications through multiple accredited testing agencies. It has been designated a new disaster-safety technology by the Ministry of Interior and Safety and a green technology by the Ministry of Land, Infrastructure and Transport. Dasco holds five related patents. The system has been installed at seven sites, including the Anyang–Seongnam Galhyeon overpass on the Second Gyeongin Expressway, the Sampyeong soundproof tunnel on the Seoul Ring Expressway, a soundproof tunnel section of the Yeongdong Expressway in Gwangyo, and the second and third residential zones of Sejong. Construction is currently under way at five additional sites.

The technologies Han holds most dear are also the ones most directly tied to human life — the guardrail and the smoke vent. "I want Dasco to be a company that contributes to society," he said. "The smoke vent technology that was recently recognized as a new disaster-safety technology is, in every sense, a technology that protects human lives."

Dasco's next arena is energy. When asked where he wants the company's identity to lie going forward, Han did not hesitate.

"I want us to be recognized as an energy technology company now," he said. Dasco is moving beyond manufacturing solar structures to cover the full value chain: engineering, procurement and construction; power project development; and plant operations and maintenance.

Han sees the company's manufacturing base as a natural fit with its energy ambitions. "The manufacturing foundation gives us cost competitiveness and serves as the base for generating steady sales and profit," he said. "Through large-scale project orders in the energy business, we are diversifying our business structure."

The company is also reshaping a business model that once relied almost entirely on EPC contracts. "As the renewable energy market shifted toward private-sector leadership, large-scale independent power producer projects ran into financing difficulties, and we were able to use the company's financial strength to invest in securing project rights," Han said. "We are now directly or indirectly involved in more than 30 projects, locking in future sales and profit — ranging in scale from 400 megawatts down to 2 megawatts."

"The tunnel noise barrier market, an infrastructure business, is one where we hold the No. 1 position in Korea and enjoy stable order intake — it is Dasco's top cash cow," Han said. "We also run a manufacturing business producing and selling deck plates and insulation boards directly. As the other businesses deliver results, they form a mutually complementary portfolio."

Dasco has set a long-term target and made the transition to an energy company its stated vision for this year. "Given the scale of the market, we plan to generate 60 percent of total company sales from the energy sector," Han said. The plan goes beyond building and handing over solar plants: Dasco intends to participate in roughly 20 years of operations and maintenance, followed by repowering — replacing aging equipment with new installations.

"The renewable energy market is one where you can keep reinvesting through repowering after about 20 years of operation," Han said. "Managing maintenance for 20 years and then responding first as an EPC contractor at the repowering stage — that will be a virtuous cycle." He added: "I hope that Dasco, surviving as a century-old company, will one day look like a power generation company operating its own renewable energy plants."

For Han, the ultimate destination of all this expansion is less about the company than about the people it can employ. Asked why growing the business matters, he reached back to an ambition he formed in childhood. "When I was young, I set my heart on succeeding in a big way — creating employment, giving many people jobs, and devoting myself to nurturing future talent," he said. "To do that, I knew I had to earn a great deal of money, and that is what has driven me."