Ecological Plus Energy Building (EPEB)

1 Transparent and Opaque envelope for heating & cooling load reduction 

The solar irradiance should be drawn into the room for the heating season, and reverse for the cooling season. Window-to-Wall Ratio is considered due to the solar properties of window glass that is transparent to visible light and short wave infrared, but opaque to long wave infra-red re-radiated from the building inside floor or walls, so that the room temperature increases.

2 Multi-functional bi-facial building integrated photovoltaic system as a shade (MB-BIPVS) and Smart Farm on the roof

The MB-BIPVS is designed to block the solar radiation entering the adjacent rooms as much as possible during the cooling period and receive the solar radiation from the front and back of the MB-BIPVS as much as possible, which can reduce the cooling load by about 34% according to the eave principles of traditional Korean house during the cooling period and generate 46% more power than the wall-mounted BIPV type.

3 Passive intelligent radiant cooling system (PIRC)

This PIRC uses just this non-portable water which is used to cool a space. It uses the updated PIRC system that requires no energy input, a PV thermal system, and radiant night cooling so that the system does not require cooling energy or additional water to cool the building. This PIRC will be installed within all floors and some walls of the NZEB test model building to cool or heat the NZEB. This NZEB applies a radiant floor hot water heating system. Hot water circulates through pipelines embedded in the concrete floor or walls to heat the interior in winter using a heat pump boiler using electricity generated by MB-BIPVS, etc. These embedded pipelines are used to cool the interior in summer. Natural City (tap) water is about 1920°C in Korea and 1014°C in some European countries in summer.

4 Cool tube and smart farm

The freshest air around the site is supplied through cool tubes installed below the frost line, supplying cool air to the room during summer. It reaches the human, and the human can efficiently breathe the fresh and cool air that is needed the most at least through the source flow radiant cooling ventilation (SFRCV). The stack ventilation could automatically take place in this SFRCV without any ventilator due to the height differences between the inlet and outlet according to the buoyancy effect. The winter garden on the southern facade and the smart farm on the roof can save about 17% of the adjacent room space's heating load in adjacent rooms if an effective air exchange between the winter garden or smart farm and the adjacent rooms takes place, providing a comfortable thermal environment and a comfortable ecological space even. In addition to the various ecological values ​​mentioned above, a winter garden equipped with 50% semi-transparent PV modules, and the MB-BIPVS can efficiently produce enough electricity.

5   Ecological design criteria for NZEB

The ecological design criteria for the concepts of the NZEB have been continuously developed in the form of documents and simulation programs to use for optimizing the NZEB and disseminating the NZEB worldwide to mitigate climate change and adaptation. The vernacular concepts for architectural elements are supplemented to consider the ecological values of regional architectural elements which are handed down for many generations. By adding the ecological value of the Ondol heating system and eaves, which are important features of traditional Korean houses, to these criteria, we aim to revive the indigenous ecological values ​​that have been passed down from generation to generation and enable residents to feel comfortable in ecological, energy, and psychological aspects. These dependent variables for the evaluation factors are almost numerically calculated and digitalized to optimize the NZEB. The digitalized results can be used to optimize the energy harvesting technologies including the renewable energy systems and passive intelligent concepts for the NZEB.

6 Final goals

Multi-lateral collaborative research conducted in at least 3 different countries optimizes the near-zero energy concept of solar buildings by examining passive intelligent energy harvesting technologies and ecological criteria for building envelope performance in a test building with a smart farm on the roof. 3 different vernacular concepts of Korean architectural elements including PIRC, MB-BIPVS, and thermal buoyancy effect are applied to develop NZEB to ecologically upgrade building energy efficiency. PIRC systems that use only the enthalpy and pressure of natural tap water can be an ecological solution for cooling the buildings for climate change mitigation and adaptation, as they do not require any cooling energy or additional water to cool the building. Finally, this type of NZEB concept could create an ecological plus energy building that could cover almost all human energy consumption within the building.