We present a representational framework for the integrated operation of multiple environmental systems in buildings. A methodology for the automatic generation of this framework is introduced. The implementation of both rule-based and simulation-based control
The current work presents features of an air-underfloor heating system and CFD model to predict velocity and temperature distribution. The paper describes the constructions of air-underfloor heat exchangers. Computational fluid dynamics professional software-ANSYS/FLOTRAN was used to simulate of turbulent airflow and radiation heat transfer in ventilated room with air-underfloor heating installation. The numerical simulation of many cases was performed to study the comfort criteria in the tested room.
Air supply diffusers used in air-conditioning systems can be classified as ceiling diffusers, sidewall diffusers, floor diffusers, jet nozzles, and low velocity displacement diffusers. Fixed or adjustable slats are usually used to control airflow directions. Recently, swirling vanes are used in floor diffusers to create swirling outflow jet, so that more rapid mixing with ambient air can be achieved. In this paper we used the latest CFD technique to investigate the airflow pattern and the impact on thermal comfort in the near nozzle region of a floorlevel swirl-type diffuser.
The low-flow solar water heater – from 7 litres/hour to 15 litres/hour per solar collector area – is the most promising way for improving the solar water heater performance. This performance can be increased taking advantage of the low flow to obtain a better stratification in the tank. For this purpose, the most promising technology uses a mantle storage tank with injection of the collector fluid at several levels. The aim of this article is to present some numerical and test results from the storage tank of a low-flow solar water heater.
This paper presents a methodology to analyse the thermal loads of non-residential buildings based on simplified weather data, which are available for 206 Brazilian locations. These data include monthly average of maximum and minimum temperatures, atmospheric pressure, cloud cover and relative humidity. For each month, two typical days are used to estimate the cooling and heating loads. The Transfer Function Method was used to run load calculations and the validation was evaluated according to ASHRAE Standard 140.
This paper presents the development of a simulation tool based on the Matlab computational environment for building temperature performance analysis with automatic control. The simulation tool contains mathematical models for buildings, HVAC (Heating, Ventilation and Air Conditioning) systems, sensors, weather data and control algorithms. The building mathematical model is described in terms of statespace variables, with a lumped approach for the room air governing equations – energy and mass balances. In this context, the simulation tool structure and components are explained.
Computer based modeling tools were used to examine the hygrothermal environment inside a heavy-masonry historic building experiencing crypto-efflorescence damage to its moisture-laden brick vault. Monitoring was carried out to investigate the damage pattern against changes in the interior environment and to validate simulation models. The models predicted a period of 1,612 annual hours during which the vault was vulnerable to salt damage under the current environmental regime and a potential reduction of this critical period by 98% as a result of a remedial measure.
This article presents a mathematical model that provides explicit support for preserving the consistency between decisions made at various points during building performance analysis. Analytical Target Cascading, a multilevel engineering design optimization framework, is applied to the energy analysis process. Within this framework, the energy analysis problem is decomposed into hierarchical levels based on individual performance goals. Interactions among all levels in the hierarchy are accounted for by linking them mathematically.
The aim of the European SSHORT (Sustainable Social Housing Refurbishment Technologies) project is to increase and promote rational and efficient use of energy in the retrofitting of social housing buildings. In this scope, one step was to develop a specific multicriteria decision-making tool to support decisionmakers in choosing the most adequate energy technological solutions for refurbishment in Europe. The tool (System Selection Tool) is based on a method for multi-criteria evaluation of combinatorial systems. The tool aims at an energy system as a combination of technical solutions.
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