# EnergyX DY-Building

EnergyX DY-Building (Korean: 에너지엑스 DY빌딩) is a zero-energy building located at 505, Hyangdong-dong, Deokyang-gu, Goyang-si, Gyeonggi Province, South Korea. The building has a total floor area of 3,274.87 m$^2$ (35,250.4 sq ft) and consists of seven floors, commercial building. The name DY-Building is derived from "Dynamic Yield".
EnergyX DY-Building is the first plus-zero-energy commercial building in Korea. From the initial design phase, the goal was to implement PEB (Plus Energy Building) concepts by minimizing energy demands through passive design and active system technologies while maximizing energy production using renewable energy sources. The building achieved an energy self-sufficiency rate of 121.7%, producing more energy than it consumes. This earned the building recognition as a "small power plant" and made it the first commercial building in South Korea to receive the highest Zero Energy Building (ZEB) certification (Grade 1) from the government.

## Applied technologies
### Passive design

To minimize the energy demand of the Energy X DY Building, high-performance insulation and window systems were applied. The thermal insulation performance of the exterior walls was designed to be 0.152W/m²K, which is 37% higher than the 0.240W/m²K standard for Climate Zone 2 in the Building Energy Saving Design Criteria. Additionally, 42mm low-emissivity (Low-E) triple glazing was installed to minimize the effects of solar radiation, including solar heat gain and window thermal transmittance.

### Active system

Active systems refer to the mechanical and electrical design phase aimed at handling the loads required to maintain a comfortable indoor environment, including cooling, heating, hot water, lighting, and ventilation.
The heating and cooling source for the Energy X DY Building is an Electric Heat Pump (EHP), while the hot water supply is provided by electric water heaters. A total of 11 EHP units have been installed, with an average Coefficient of Performance (COP) of 3.54 for cooling and 3.72 for heating, utilizing first-grade energy efficiency products. To enhance indoor air quality and comfort, a ventilation system has been introduced, and 39 total heat exchangers have been installed across various zones. The minimum effective heat exchange efficiency has been set to over 50% for cooling and over 70% for heating to reduce energy consumption.
For lighting, high-efficiency energy-certified LED lighting products were selected for each zone, with a lighting control system installed to reduce operational energy consumption. The lighting system is integrated with the Building Energy Management System (BEMS), and the control system is configured to adjust indoor LED lighting brightness in three levels.

### Photovoltaic system

A photovoltaic system, also called a PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics.
The PV modules have been installed on the roof and sloped areas. A total of 81 kW of PV modules have been installed, with 63 kW placed horizontally on the roof and 18 kW installed on the sloped areas of the roof.

### Building Integrated Photovoltaic System

Building-integrated photovoltaics (BIPV) are photovoltaic materials that are used to replace conventional building materials in parts of the building envelope such as the roof, skylights, or façades.
To achieve energy self-sufficiency, simply covering all available building façade spaces with solar panels would be the easiest approach, but this would compromise the building's design. To address this, the Building-Integrated Photovoltaic (BIPV) system was developed. This system replaces conventional building materials with photovoltaic modules that not only serve as the exterior cladding but also generate electricity.
In the case of the Energy X DY Building, the façade was designed using a curtain wall system, and the solar modules were planned as follows: BIPV-1 (spandrel panels), BIPV-2 (vision area), and BIPV-3 (opaque cladding materials). This integration allows the building to maintain both aesthetic appeal and energy efficiency.
Solar Installation Locations and Capacity for the Energy X DY Building
| Category | Section | Area(m²) | Capacity(kW) |
| PV | Rooftop Horizontal Surface | 298.98 | 63.00 |
| PV | Sloped Roof Surface | 85.42 | 18.00 |
| BIPV-1 SKALA | Façade (West, South, Southwest) | 453.12 | 60.20 |
| BIPV-2 VISION | Façade (West, South, Southwest) | 440.82 | 21.35 |
| BIPV-3 POWERMAX | Façade (Southeast) | 168.60 | 24.00 |
| Total | Total | 1,446.94 | 186.55 |
| Final ZEB Certification Self-Sufficiency Rate | Final ZEB Certification Self-Sufficiency Rate | 121.7% | 121.7% |

## Records

* South Korea's First Commercial Plus Zero Energy Building
* Achieved Building Energy Efficiency Rating 1+++
* Attained Energy Self-Sufficiency Rate of 121.7%