IDA Indoor Climate and Energy is a recently developed tool for building performance modelling and simulation. It represents a new generation of BPM software in several ways. (1) It is entirely imple- mented in a general-purpose simulation environment, IDA. (2) All models are available as NMF source code. (3) It covers a range of advanced phenomena such as integrated airflow and thermal models, CO2 modelling, and vertical temperature gradients. (4) It has a multi-level GUI to accommodate different types of users.
The convective heat transfer coefficient at an outer ambient wall with a window exposed to natural climate was measured in a room with and without furniture. The method used was to estimate the heat flow from measured temperatures and solar radiation. The convective heat transfer was calculated as the difference between the heat flow through the building element and the calculated longwave radiation. The accuracy was at best ±15% for the window and ± 20% for the wall. Even so the effect of different heating and ventilation strategies on the inside could clearly be detected.
The paper describes the development of a su pervisory control scheme that adapts to the presence of degradation faults and minimises any resulting increase in energy consumption or deterioration in occupant comfort Since there is a high degree of uncertainty associated with the results of any fault identi cation scheme in information poor systems of this type the supervisory control scheme uses fuzzy models to predict fuzzy measures of the overall performance and a fuzzy decision maker to determine the most appropriate set points This fault tolerant control scheme is being d
Abrupt faults on HVAC components as blocked dampers or broken fan belt can be successfully detected by methods based on logic rules. On the other hand, those method are less efficient to detect fouling on coil or scaling in tubes that are progressively decreasing the energy efficiency and are long-lasting phenomena. Previous work on simulation data shows that methods based on artificial neural networks (ANN) are adapted to solve this problem.
In this study, energy simulation program of heat distribution network in a district heating and cooling system was developed. Research on actual condition of heat distribution system of DHC plant was also executed. Using the measurement result, the accuracy of the program is confirmed. Using this program, the relationship between scale of pipeline network and energy consumption of heat distribution system was examined. In the final part, importance of chilled water temperature differences at the building side for energy performance of DHC is clarified quantitatively.
The purpose of this study was to evaluate the capabilities of four energy analysis software to predict the energy performance of an existing house. The discussion covers: (i) the modelling-related issues, and (ii) the impact of modelling accuracy on the prediction of energy and cost savings
Three indices are introduced in order to evaluate cost saving operation of chillers using nighttime low electric power rates for thermal storage systems with water tanks. A storage tank discussed here is a multi- connected complete mixing type, which is widely used in Japan. The indices are calculated with some measured data. In this paper, definitions of the indices are described, and one of evaluation results in actual office buildings is shown.
Simplified equations are established to estimate the energy consumption for the heating and cooling of residences, with the coefficients like air-conditioning area rate, air-conditioning-hour rate, etc.. To determine these coefficients, a detached house model is supposed. The air-conditioning load of the house in different regions is calculated with a thermal performance simulation program called the PSSP. With the simplified equations, the primary energy consumption in the future is estimated.
In this paper, an approach to the optimum volume of rock bed, its charged thermal energy and the optimum air flow rate for an air-based solar heating system in charging mode is presented. The relationship between the optimum volume of rock bed and the air flow rate is approximately obtained as a theoretical solution of the linear approximation equation, and the charged thermal energy in the rock bed is approximately obtained as a function of the air flow rate.
With the advent of the computing age, heat balance based techniques for simulating thermal loads in buildings became a reality for architects and engineers. However, since the 1970s, the capabilities of most of the well-known heat balance based simulation programs have remained fairly stagnant. Much of the reason behind this trend lies with the complexity of the programming required to deal with the fundamental physics encountered in a building and the relative simplicity of the programming languages that were available.
Login