Simulation

Energy simulation is a computer-based analytical process that helps building owners and designers to evaluate the energy performance of a building and make it more energy efficient by making necessary modifications in the design before the building is constructed. Use of energy simulation software is necessary to show compliance with Indian Energy Conservation Building Code (ECBC) via “Whole Building Performance Method.”

Energy performance simulation tools allow designers to:

• Consider the building as a single integrated system
• Predict thermal behavior of buildings in relation to its outdoor environment
• Predict the impact of daylight and artificial light inside the building
• Model the impact of wind pattern and ventilation and assess its effect on energy use
• Estimate the size/capacity of equipment required for thermal and visual comfort
• Calculate the effect of various building components on each other and predict resulting conditions and impact on energy use
• Assess the changes in energy consumption through sensitivity analysis with respect to design changes affecting building geometry and materials, components, systems, etc.

**Courtesy: ECBC Tip Sheet

Lighting is a major energy consumer in commercial buildings. Heat generated from electrical lighting also contributes significantly to the energy needed for cooling of buildings. ECBC prescribes the amount of power for lighting, specifies types of lighting controls, and defines situations where daylighting must be used. Two types of lighting simulations are as below:

Daylighting Simulation

A computer-based calculation of the amount of daylight available inside or outside of a building under one or several sky conditions. Simulation outputs may be discrete numbers (illuminances and luminances) under selected sensor points within a scene or visualizations of a scene.

Daylighting reduces the need for lighting energy , which when integrated with the approach to lighting design can contribute to a decrease in the energy consumption. It is estimated that a well day-lit building can reduce lighting energy use by 50 to 80%.

With the use of modeling software tools, ALF Green can help the design team to enhance daylighting availability in most regularly occupied spaces in the building, thereby providing a comfortable environment to the occupants while reducing energy consumption.

Artificial Lighting Simulation

A computer-based calculation of the amount of man made lighting that is being used or required in a building. A building’s interior lighting system effects both the emotional and physical well being of the occupants in addition to major consumption of electrical energy and also a source of internal heat.  Specifying energy efficient lighting system which uses both natural and lighting controls will provide a comfortable visual environment to the occupants.

The simulation process is completely integrated with the other design services (architectural, structural, energy modelling, utilities etc. With the use of modeling software tools, ALF Green can help the design team to achieve highly efficient artificial lighting systems.

Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses numerical analysis data structures to analyze and solve problems that involve. Computers are used to perform the calculations required to simulate the free-stream flow of the fluid, and the interaction of the fluid (liquids and gases) with surfaces defined by boundary conditions.

CFD is the analysis of systems involving fluid flow, heat transfer and associated phenomena such as chemical reactions by means of computer-based simulation. The technique is very powerful and spans a wide range of industrial and non-industrial application areas. Some examples are:

• External and internal environment of buildings: wind loading and heating/ventilation 
• Aerodynamics of aircraft and vehicles: lift and drag 
• Hydrodynamics of ships 
• Power plant: combustion in internal combustion engines and gas turbines 
• Turbomachinery: flows inside rotating passages, diffusers etc. 
• Electrical and electronic engineering: cooling of equipment including microcircuits 
• Chemical process engineering: mixing and separation, polymer molding 
• Marine engineering: loads on off-shore structures 
• Environmental engineering: distribution of pollutants and effluents 
• Hydrology and oceanography: flows in rivers, estuaries, oceans 
• Meteorology: weather prediction 
• Biomedical engineering: blood flows through arteries and veins

**Courtesy: An Introduction to Computational Fluid Dynamics by H K Versteeg and W Malalasekera