Numerical modelling of flow through air conditioning diffuser

A high quality indoor environment, essential for occupant’s health, comfort and productivity, is the need of the present world. Room air simulations are being carried out to predict the airflow inside the room. The airflow properties just at the exit of

Energy Efficient Office Buildings with Passive Cooling Results from a Research and Demonstration Programme

To gain access to information on energy use in office buildings, the German Federal Ministry forEconomy launched an intensive research and demonstration programme in 1995. In advance of theEU energy performance directive a limited primary energy coefficient of about 100 kWh m-2a-1 as agoal for the complete building services technology was postulated (HVAC + lighting) for alldemonstration buildings. A further condition was that active cooling be avoided.

Development of the HVAC Control System by the Concurrent Simulation

The idea proposed in this paper is to control the HVAC equipment with predicting the heating/cooling loads and indoor conditions by computational simulation according to the target, such as energy consumption, energy cost, CO2 generation and indoor thermal comfort. The simulation inputs is given by the measurement results, e.g. weather conditions, indoor temperature and humidity on the spot. The developed system controls HVAC system by using the real-time simulation, and investigates the performance of this system.

Consequences of Increasing Insulation on the Annual Energy Consumption of Air-Conditioned Office Buildings

The aim of this work is to study the influence of global heat transfer coefficient (Utot en W/m2.K) of the opaque walls (walls and roofs) and of the glazed walls (bays) on the annual consumption of heating, cooling and overall consumption energy. We analyze the number of hours of heating and cooling under operation with partial load and full load. Profiles of indoor temperatures are also given. The work is established on several office buildings defined according to a typology built within the framework of a study on energy savings in air-conditioned office buildings in France.

Ventilation and work performance

The paper evaluates the potential work performance benefits of increased ventilation. We analysed the literature relating work performance with ventilation rate and employed statistical analyses. The studies included in the review assessed performance of various tasks in laboratory experiments and measured performance at work in real buildings. Almost all studies found increases in performance with higher ventilation rates. The studies indicated typically a 1-3 % improvement in average performance per 10 L/sperson increase in outdoor air ventilation rate.

Zonal Modeling of Double-Skin Facades

This article presents the application of the zonal approach for modeling airflow and temperaturedistribution in Doube-Skin Facades (DSF). The airflow rate was calculated by using the power-lawmodel (PLM) and integral form of the energy equation was used to evaluate the temperaturedistribution. The predicted temperature distribution was compared/ verified using measured valuesand parametic studies were conducted to identify the influence of height, flowrate and pesence ofshading device on the temperature gradient in the cavity.

Why HVAC Certification for Balancing and Commissioning Contractors is Necessary for VentilationMeasurement, Verification, Validation and Decreased Energy Consumption

This presentation will make the audience aware of the importance of ISO-recognized certificationprograms in the testing adjusting and balancing and commissioning of HVAC systems. ImportantISO 17024 standards will be covered as well as their importance. Many faults have been found inexisting testing adjusting and balancing and commissioning certification programs ranging fromconflicting issues within the organization and their testing procedures; political control over theprocess; inconstant certification methods; geographical differences.

Ventilation Performances of Mixing, Displacement, and Impinging Jet System under Different HVAC Scenarios : Part II

In most conditioned spaces, the Mixing Jet Ventilation (MJV) systems are commonly installed. Relying on turbulent mixing, MJV homogeneously controls the room environment. However, Indoor Air Quality (IAQ), draft, and noise can sometimes be drawbacks of MJV systems. In late the 70s, Displacement Ventilation (DV) was first introduced. By supplying low supply velocity air from the floor or lower wall, a stratification zone is formed which forces pollutants to be collected near the ceiling and allows clean air to remain in the breathing zone.

Ventilation Performances of Mixing, Displacement, and Impinging Jet System under Different HVAC Scenarios : Part I

In most conditioned spaces, the Mixing Jet Ventilation (MJV) systems are commonly installed. Relying on turbulent mixing, MJV homogeneously controls the room environment. However, Indoor Air Quality (IAQ), draft, and noise can sometimes be drawbacks of MJV systems. In late the 70s, Displacement Ventilation (DV) was first introduced. By supplying low supply velocity air from the floor or lower wall, a stratification zone is formed which forces pollutants to be collected near the ceiling and allows clean air to remain in the breathing zone.

Validation of Tools used for HVAC Simulation

The joint IEA research project of ECBCS Annex 43 / SHC Task 34 “Testing and Validation of Building Energy Simulation Tools” contributes to evaluation, diagnosis and improvement of building energy simulation tools. So it carries forward a process that has

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