Improving simulation accuracy through the use of short-term electrical end-use monitoring

Hourly simulation programs such as DOE-2, HAP and BLAST can effectively simulate the performance of HVAC systems in response to seasonal weather patterns. However, the schedules of use for key internal loads are often given insufficient consideration, leading to a reduction in accuracy. Schedules are often overly simplified and based on insufficient information about how a building is used.

Improvement of accuracy in lighting simulation by flux transfer method

In  this  paper,  we  describe  the  characteristics  of “Luminous Planner” as a general-purpose lighting design tool, and of “LSR(Lighting Simulation Radiosity)”, which is capable of high-precision lighting simulation by taking space reflection into consideration. The “LSR” divides architectural shapes into small polygons and pursues flux transfer in each small polygon. We applied the progressive refinement approach to the “LSR”, required calculation time and memory have been reduced.

Ida indoor climate and energy

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.

Heat transfer coefficients in a full scale room with and without furniture

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.

Fuzzy model-based fault-tolerant control of air-conditioning systems

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

Fault detection and diagnosis on HVAC variable air volume system using artificial neural networks

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.

Evalution of distribution system performance in district heating and cooling system

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.

 

Evaluation of energy performance of an existing house in montreal using four energy analysis software

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

Evaluation and simulation of cost saving operation for thermal storage HVAC system

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.

Estimation of energy consumption for air-conditioning of residences

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.

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