validation

This paper presents a thermal simulation validation study of the typical precision that a trained thermal simulation engineer can expect to obtain for the simulation of a room connected to a naturally ventilated double skin facade. The open source building thermal simulation tool EnergyPlus is used to predict air and surface temperatures in a free running weather exposed test cell.

This paper presents a validation of airflow network (AFN) and computational fluid dynamics (CFD) simulations for a naturally ventilated office building using wind tunnel measurements as the reference for external pressure coefficients and effective airflow rate prediction. The CFD simulation model is also used to study the effect of partially open windows on the effective flow rate. This study also includes a design exercise for a naturally ventilated office building that analyses the differences in predicted average window open area for a typical weather year.

Smartness is all around us. The HVAC industry is developing more and more products that have sensors, are intelligent, are connected to the Internet and are being controlled via apps. According to a recent European survey among installers, the request and demand from clients for installing home automation and smart products is the highest for HVAC installations. 

Ventilative cooling (VC) is an application (distribution in time and space) of air flow rates to reduce cooling loads in spaces using outside air driven by natural, mechanical or hybrid ventilation strategies. VC reduces overheating in both existing and new buildings - being both a sustainable and energy efficient solution to improve indoor thermal comfort. VC is promising low energy cooling technology that has potential to substantially reduce the use of mechanical cooling in airtight and highly insulated buildings.

Methods of manipulating building envelope wind pressure distributions for application in the natural ventilation of high-rise buildings are presented using computer simulation methods. CFD was used to simulate the external flow while the multi-zone method was used to compute the flow distribution in the building interior. First, a 2-D CFD study was conducted to explore various techniques of manipulating the building envelope wind pressure distribution.

The transient accessibility of supply air (TASA) and transient accessibility of contaminant source (TACS) in ventilated rooms are important indices to evaluate the effect of ventilation and the indoor air quality (IAQ). These indices can be measured by experimental method or calculated with computational fluid dynamics (CFD) tools. Compared to the measurement method, the numerical method has a lot of advantages such as fast, flexible and with detailed data. In this paper, the calculation and validation of the TASA and TACS are introduced.

This paper investigates the impact of well geometry and surface reflectance on vertical daylight levels in atria with square forms under a CIE standard overcast sky. By reviewing some previous investigations and comparing with scale model measurements the vertical daylight factor calculated using Radiance are validated. More simulated vertical daylight factors for a very wide range of atrium geometries and reflectances are given. From the results the attenuation and distribution of the vertical daylight levels on the wall of a square atrium with different reflectances are displayed.

To reduce the potential risk of airborne infectious diseases during an outbreak or to detect a chemical/biological release by a terrorist, it is essential to place appropriate chemical/biological sensors in commercial airliner cabins. This investigation studied sensor responses along the length of a fully occupied twin-aisle cabin with 210 seats by using a validated Computational Fluid Dynamics (CFD) program. The results revealed that seating arrangements can make cross sectional airflow pattern considerably asymmetrical.

In reaction to the European Energy Performance of Buildings Directive (EPBD), existing and newly lanced standard developments by CEN (European Committee for Standardization) were harmonized and synchronized, resulting in a set of about 50 standards addressing different aspects of the EPBD and the implementation of an overall building energy performance calculation method. A few of them address simulation issues: An overview of these is given, focusing on one standard covering system related aspects for buildings with cooling, humidification or dehumidification.

The aim of this study was to develop a simplified CFD model for the inlet jet of a swirl diffuser for the simulation of room airflow patterns. The swirl diffuser creates a complex flow pattern with high induction of room air, thus possessing a challenge for simulation. The studied diffuser was a model intended to be used in large enclosures. The flow pattern was adjustable between two basic modes: radial swirl jet for cooling conditions and compact downward swirl jet for heating conditions. For developing the CFD model, a series of laboratory measurements of the flow field was carried out.