Multi-Objective Optimization of the Envelope of Building with Natural Ventilation

Abstract

Abstract:A properly designed house should provide occupants with the high level of thermal comfort at low energy demand. On many occasions investors choose to add additional insulation to the buildings to reduce heat demand. This may lead to overheating of the building without a cooling system in summer periods (these prevail in Poland). Additionally, it affects the deterioration of thermal comfort, which can only be improved by increasing ventilation. The paper presents the multi-objective optimization of the selected design parameters in a single-family building in temperate climate conditions. The influence of four types of windows, their size, building orientation, insulation of external wall, roof and ground floor and infiltration on the life cycle costs and thermal comfort is analyzed for the building without cooling. Infiltration changes during the simulation and is controlled by a special controller. Its task is to imitate the behavior of occupants in changing the supply airflow. Optimal selection of the design parameters is carried out using Non-dominated Sorting Genetic Algorithm II (NSGA-II) by coupling the building performance simulation program EnergyPlus with optimization environment. For the single-family house, optimal values of design variables for three different criteria are presented.

Energy Modelling and Calibration of Building Simulations: A Case Study of a Domestic Building with Natural Ventilation

“…Heating, ventilation, and air-conditioning of buildings account for a significant part of global energy consumption [1]. Studies have determined that buildings represent more than 40% of total energy consumption in the European Union [2,3].…”

“…Methods have been developed to determine the building air change rate (ACR) in residential buildings [1] and its impact on the energy performance studied within cold climate countries [5]. The most widespread technique used is the blower door test that quantifies the flow of air due to losses when a pressure difference is applied in a sealed building.…”

“…Although studies indicate that heating energy demand derived from air infiltration can be considerable [6], the oversimplification of its treatment in modelling and analysis is recognized [1,[10][11][12]. In residential buildings where natural ventilation is not controlled, the prediction of air change rate is complicated by its dependence on temperature difference and wind speed.…”

“…In the assessment field, software programs for simulating the building energy performance have become essential tools, for example, Energy Plus, DOE-2, TRNSYS (TRaNsient SYstem Simulation program), or ESP-r (Environmental Systems Performance-Research) [1,[9][10][11][12][13][14][18][19][20][21], which typically assume constant air infiltration rates [12]. A number of assumptions need to be made and these can vary between buildings, hence model calibration is an important factor [19].…”

Heat and Air Flow Behavior of Naturally Ventilated Offices in a Mediterranean Climate

“…Ach is necessary for the determination of indoor air temperature for naturally ventilated buildings [19]. Ach should be 12 ach for a new healthcare building and 6 ach for existing healthcare buildings [20,21]. The average air speed should be 0.20 m/s with an average metabolic rate between 1 and 2 met, and clothing insulation between 0 and 1.5 clo according to the ASHRAE standards [22].…”