Performance of mixed-mode cooling strategies for office buildings in arid climates

Mixed-Mode ventilation is an innovative approach that maximizes the use of natural ventilation and uses supplementary mechanical cooling only when strictly required. The application of Mixed-Mode ventilation in severe arid climates and its integration with other passive cooling strategies is very challenging and has not been systematically studied. The paper will present an evaluation of the performance of different Mixed-Mode cooling strategies for a single-zone office space in four main arid cities that represent the diversity in arid climates.

Evaluation and optimization of air-conditioner energy saving control considering indoor thermal comfort

For the purpose of reducing the room air-conditioners’ energy consumption, an energy saving control method is proposed formerly. In this paper its energy saving effect is confirmed through experiments conducted in six office rooms in actual use. The experiment results show that the air-conditioners controlled by the present energy saving control logic and parameter settings can save electric power up to 3.0% compared to ordinary control.

Uncertainty and sensitivity analysis for detailed design support

Nowadays, building performance simulation (BPS) is still primarily used for code compliance checking in the Netherlands whilst it could provide the user already useful design information by e.g. indicating design solutions or introducing uncertainty analysis (UA) and sensitivity analysis (SA). This paper summarizes results from an ongoing research introducing UA and SA in BPS. A case study is performed based on a hypothetical building which is part of an international test method for assessing the accuracy of BPS tools with respect to various building performance parameters.

Monitoring and evaluation of night-time ventilation and radiant cooling concepts applied to low energy office buildings

This article presents a simulation study comparing the thermal interior comfort performance, the energy consumption and the efficiency of (i) nighttime ventilation concepts considering varying air change rates, (ii) three thermo-active building systems (TABS) and (iii) ceiling mounted radiant cooling panels in a low energy office building for a chosen climate of the Test Reference Year (TRY) weather database as well as for the hot summer 2003 in South-West Germany.

Cooling effects of waterways on thermal comfort in urban districts during summer

This study assesses the extent of the cooling effects of waterways on the thermal environment of urban districts of Osaka by measurement and simulation. The thermal environments of districts with and without waterways were measured in summer. The effects of the change of configuration of the district near waterway were calculated using computer fluid dynamics simulation. Results show the following. 1) Measured daily mean air temperatures were 0.5–0.8 K lower and SET* was 1.4–2.9 K lower in the district with the waterway than those in the district without waterways in peak summer.

Using energy simulation to operative temperature evaluation

According to the Czech legislative act the operative temperature is the evaluation criterion for thermal comfort in air-conditioned or heated spaces. The operative temperature respects the air temperature; mean radiant temperature and air velocity. For mean radiant temperature calculation the surface temperature of the surrounding walls must be known. Manual calculation of the mean radiant temperature is very complicated and not suitable for practical usage since the surface temperatures are difficult to determine.

Utilizing high performance supercomputing facilities for interactive thermal comfort assessment

We outline the current state of the development of a computational steering environment (CSE) for the interactive simulation and local assessment of indoor thermal comfort. The system consists of a parallel CFD kernel, a fast 3D mesh generator and a virtual reality-based visualization component. The numerical method is based on a lattice Boltzmann algorithm with extensions for simulations of turbulent convective flows.

A window opening algorithm and uk office temperature: field results and thermal simulation

This investigation of the window opening data from extensive field surveys in UK office buildings investigates 1) how people control the indoor environment by opening windows, 2) the cooling potential of opening windows, and 3) the use of an “adaptive algorithm” for predicting window opening behaviour for thermal simulation in ESP-r. We found that the mean indoor and outdoor temperatures when the window was open were higher than when it was closed, but show that nonetheless there was a useful cooling effect from opening a window.

Transitional spaces in São Paulo, Brazil: mathematical modeling and empirical calibration for thermal comfort assessment

This paper presents different thermal comfort models and empirical verification for assessment of the thermal conditions of transitional spaces in the city of São Paulo, Brazil. The method adopted is deductive, performing simulations of predictive models, and experimental inductive, considering field research of micro-climatic variables and subjective answers.

Comfort driven adaptive window opening behavior and the influence of building design

It is important to understand and model the behaviour of occupants in buildings and how this behaviour impacts energy use and comfort. It is similarly important to understand how a buildings design affects occupant comfort, occupant behaviour and ultimately the energy used in the operation of the building. In this work a behavioural algorithm for window opening developed from field survey data has been implemented in a dynamic simulation tool. The algorithm is in alignment with the proposed CEN standard for adaptive thermal comfort.

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