Submitted by Maria.Kapsalaki on Wed, 04/17/2019 - 16:00
This article proposes to study the impact of envelope and internal partition walls airleakage distributions, on the indoor air quality (IAQ) performance. It is based on a preliminary performance-based approach using formaldehyde with three emission levels (low, medium, high). This multizone modelling (CONTAM) approach uses as performance indicators, the average concentration per room as well as the percentage of time of exceeding the limit value (ELV) of 9 µg.m-3.
Empirical validation studies of the application of multizone indoor air quality models to residential-scale buildings are reviewed here. The focus is on empirical verification efforts. Models have also been subjected to analytical verification and inter-model comparisons. Not many of the empirical verifications reported statistical analyses of the comparison between measurements and predictions. Additional statistical analyses have been performed and reported if sufficient data were available in the literature. Measurement uncertainty was not dealt with in most of the published reports.
The aim of this paper is to verify the applicability of coupling thermal and multizonal simulation codes to the study of hybrid ventilated buildings. One of the main problems in hybrid ventilation building design is the evaluation of ventilation control strategies. This point has rarely been adequately developed during design phase by means of dynamic simulations analysis; often actually an insufficient analysis of control strategies it has revealed to be the first cause of complaints from the occupants. This paper aims at demonstrating a satisfactory solution of this problem.
Multizone modelling is a way to determine the air flows in a complex ventilated building subject to internal and external loads. The purpose of this work is to consider and quantify the influence of randomness in the load parameters, which is accomplished by means of a stochastic multizone model. In the first place a deterministic multizone model is applied. The model is capable of predicting air flow and pressure distribution within a building divided into an arbitrary number of zones and flow paths. The air flow is driven by pressure differences due to wind and stack effect.
Multizone modeling refers to analysis techniques that use a simplified, zonal representation of a building to study building airflows, pressure differences, and contaminant transport. Each zone is assumed to have uniform temperature, pressure, and contaminant concentrations. Zones typically represent individual rooms but can be entire levels depending on the building layout and the goals of the modeling. Zones are connected through flow paths represented mathematically by pressure-flow relationships. This article describes CONTAMW [Dols et al. 2000], a multizone modeling tool.
Zonal models are often used in analytical calculation of temperature, concentration or humidity conditions in ventilated spaces. The space is divided in two or several zones ( 1 ). The zoning of the space is based on the assumption of constant temperature, concentration and humidity in each separate zone. The balances for air mass flow, contaminant mass flow, water vapour mass flow and heat flow are determined between zones and between zone and outer boundaries.
A literature search was undertaken to assemble and interpretthe-best available· data that can be used for perfonning multizone airflow modelling in mid and high rise apartment buildings. The best currently available data is presented and areas where further field testing research is required are identified. A multizone airflow modelling software tool was used to provide an analysis of ventilation related energy issues in a newly constructed 10 story high-rise apartment building.
The prediction of energy use, air flows and temperatures in different rooms of a building andat different climatic conditions is very important, especially when evaluating new conceptsfor heating and ventilation systems in combination with different building envelopeconstructions. A thorough system analysis considering coupled air flow and thermalcalculations becomes very complex if e.g. thermal bridges and dynamic conditions areconsidered.
Discusses two completed annexes of the IEA Energy Conservation in Buildings and Community Systems Programme, Multi-zone air flow modelling, and Energy efficient ventilation of large enclosures. For the former, it considers the tasks, the algorithm, the user interface, numerical reliability, evaluating potential user difficulties, comparing numerical predictions with experimental data, outcome and conclusions. For the latter, considers background and objectives, the tasks, the design principles guide, analysis and prediction techniques, case studies and outcome and results.
In this paper, we are particularly interested in the automatic generation of zonal model. We show how a. program can deduce with expert rules a partitioning suitable for the main driving flows encountered in the room under study and how appropriated local model are chosen and connected each other. To illustrate our purpose, we solve the case of a ventilated bi dimensional cavity.