Yoon-Bok Seong

Optimized control algorithm for automated Venetian blind system considering solar profile variation in buildings

Automated blinds need to be controlled to maximize benefits of daylight to enhance occupant comfort and to reduce energy consumption. However, previous control methods focused on minimizing the negative impacts of daylight, but failed to maximize the positive impacts of daylight and solar heat gain. The objective of this study is to develop an optimized control algorithm for automated venetian blind which would reduce the negative effects of incoming daylight on visual comfort of occupants, and to minimize psychological anxieties caused by frequent motions of the blind, by maximizing the positive effects of incoming daylight and solar irradiation, by opening/closing of the blind. Through implementation of the proposed methods and algorithms, the direct glare on work-planes could be prevented at all time, and also incoming daylight and solar irradiation could be increased.

Optimum Blind Control at the End of Operation Time Zone for Preventing Glare on Work-plane and Maximizing Daylight and Solar Heat Gain

The objective of this study is to develop the blind control strategy and method which reduce negative effect of incoming daylight on visual comfort of occupants, minimize psychological anxieties caused by frequent motions of a blind, and maximize positive effect of incoming daylight and solar irradiation by opening/closing of a blind. As previous researches on blind controls have limited outdoor environmental conditions to those in specific regions, orientations and dates, these resulted in problems at various conditions for general-purpose application. Major problem is that the time interval and amount of blind movement do not meet the control objective at the end of control zone and discontinuous curve. To overcome these limitations revealed in the previous researches, following tasks were performed in this study. 1) To establish the control objective to accomplish the goal of this study. 2) To develop the control methods and algorithms which prevent glare on the work-plane at any time and which control the time interval and amount of blind movement to follow the control objective at various profile angle curves. 3) To validate the general-purpose applicability and performance of the developed control methods and algorithms by simulation and its data analysis at various conditions. It was found that the proposed methods and algorithms can prevent the direct glare on the work-plane at all the time and also increase the incoming daylight and solar irradiation.

Corrections for minimizing solar profile prediction errors and methods for preventing direct glare on the workplane in blind control

As a means of improvement of environmental comfort in buildings with blind control, the objective of this study is to minimize solar profile prediction error for the purpose of preventing direct glare caused by the sunlight inlet in blind control. During the process of solar profile prediction, the main variables that cause prediction error of the solar profile were defined and problems from the prediction error were analysed. Surface orientation and time are significant factors that may cause error and glare during blind control. This research proposes and evaluates the correction methods and control strategy to minimize prediction error. In this research, the proposed correction methods and control strategy, which considers the surface orientation based on True North and potential time errors, could solve problems of direct glare caused by daylight inlet on the workplane, according to prediction errors of the solar profile. These methods could also be used to maximize daylight and solar heat gain, because the blocked area on windows could be minimized.

Numerical analysis model to evaluate the agricultural solar right in rural area with a consideration of building and infrastructure constructions

Recent construction of building or infrastructure has included many new bridges, in an effort to create new infrastructure while disturbing the natural environment. The new bridges have created disputes over agricultural solar right in rural area. The main issues of the dispute were the reduction of crop yields and increased heating costs. To settle these solar right conflicts, it is necessary to develop an evaluation method and quantitative guidelines for determining the infringement of solar right in rural areas. The objective of this study is to develop a numerical analysis model to evaluate the infringement of agricultural solar right by the construction of infrastructure such as highway bridges. For this purpose, we have reviewed the general mediation process and proposed the numerical analysis model which is based on the WALDRAM diagram method. This model was integrated with the evaluation tool which quantitatively estimates the infringement of agricultural solar access due to the construction of building or infrastructure. And we verified the effectiveness of the proposed numerical model through the application to actual cases.

HELIOS-EX: Blind control simulator and method with a consideration of adjacent buildings

Blinds are a common type of shading device and are increasingly operated automatically to overcome the limitations of manual operation. Automated blinds need to be controlled to maximize benefits of incoming daylight (sunlight and skylight) and solar irradiance for enhancing occupant comfort and reducing energy consumption. However, most previous control methods focused on minimizing the negative impacts of daylight, and so failed to maximize the positive impacts of daylight and solar heat gain. Furthermore, all of previous blind control methods never consider the impact of adjacent buildings. The rates of sunlight, skylight and solar irradiance to indoor are fluctuated by the disturbance of solar access, which can cause visual discomfort of occupants such as glare and have an effect on energy consumption due to variations of heating or cooling load. The objective of this paper is to propose the automated blind control strategy considering adjacent buildings’ geometry in order to minimize the occupants’ discomfort from glare and to maximize daylight inlet and solar heat gain, which can contribute to reducing energy consumption in a building. The proposed strategy was evaluated and verified through the computer simulations and analysis of results.