Energy codes for new construction set the minimum guidelines or a baseline standard in which to gauge the energy design efficiency of new builders. Going beyond government standards to fully optimize building efficiency is no longer viewed as an undesired increase in initial costs. Compliance to ever expanding building energy codes has become more agreeable to owners and project stakeholders as deep energy savings and automated facilities management bring a calculable and predictive return on investment.
The full benefits of building energy codes are not only monetary but include governmental demands to reduce the environmental impact caused by carbon emissions and the use of fossil fuels as a primary energy source. The US Department of Energy (DOE) gives an illustration of energy cost savings directly attributed to the impact of building energy code enforcement for residential and commercial structures (cumulative 2010-2040), as follows:
- 12.82 quads of primary energy saved
- 841 MMT of reduced carbon emissions
- $126 billion energy cost savings
Thermal modeling services will reduce the initial costs of engineering, installed equipment, and the construction of optimized energy efficient buildings by balancing building envelope material, installed system costs, building code compliance, and occupant comfort levels, along with increased systems management functionality and reducing future maintenance costs. A thermal management solution can be determined which is cost effective and takes advantage of active energy systems and installed equipment, natural and passive energy resources, along with the building layout.
Integrated Energy Efficient Building Design and Construction
Engineers, architects, designers, and contractors seek energy-efficient solutions from a variety of methods. This integrated energy design and construction technique employs the inherent design of the building, installation of insulating materials, the utilization of energy-rated equipment, and the harvesting of natural and passive energy sources, to establish an interactive system of energy efficiency.
Our engineers work with client input to provide building simulation and comparison of thermal models using computer-aided engineering (CAE) software and advanced graphics technology. Our skilled engineers utilize mathematical analysis and a multi-physics approach of thermal dynamics and CAD thermal simulation and visualization software to:
- predict how construction materials will manage heat under dynamic real-world scenarios
- provide an effective way to simulate real-world HVAC systems thermal management problems and solutions
- remove barriers that hamper energy efficiency without over-riding construction cost budgets
- visualize a full range of temperature distribution parameters throughout the structure to solve for thermal convection, conduction, and radiation under both steady-state and transient conditions
The task of predicting the thermal performance of your building and its energy systems requires specialized tools and the precise construction of a thermal model, which represents and emulates building components as they react withing the physical laws of heat transfer. These include room air, windows, walls and slabs under volumes of air movement, heat capacity, internal loads, convective and conductive heat transfer of surfaces, ventilation, and many other parameters.
Structural Analysis Thermal Model Simulations
A thermal model simulation based on structural components can visually display the heat flow through the building in either a steady state (without change) or as a transient condition, where the natural laws of thermodynamics are applied. This type of analysis will consider the construction material properties, and calculate the temperatures and heat flow between them.
In addition to the structural model analysis, a thermal fluid analysis can be simulated, where the effect of air (or liquid) movement is calculated and simulated. The data gained from thermal fluid analysis can be used extensively by HVAC engineers to begin the equipment specification process, such as environmental comfort factors and air quality levels.
A thermal model based on structural analysis and thermal fluid analysis, when properly loaded and configured, will simulate the total energy use of the building, including ventilation, heating/cooling, lighting, and hot water. In addition to these fixed energy sources, the inclusion of solar radiation absorbed through the building surfaces will enable a complete thermal model simulation which can be used by engineers and architects for the following design and construction considerations:
- building site orientation, envelope and window shading requirements
- construction and building activities schedules
- internal loads of spaces (including leakages)
- load calculations for thermal zones
- air, plant, and zone HVAC requirements
- return and supply plenum loads
- service water heating setpoints
- refrigeration system capacities
- lifecycle costs or utilization
- future utility bill calculations
Thermal Model Comparisons of Building Enclosures and Systems
The maximum amount of heat loss of a building can be prescribed by it’s ‘energy frame’ – which is the mathematical value of energy losses allowed and is calculated from the accumulated simpler values such as temperature, u-values, solar heat gains, etc. This method will give an overall thermal value per square meter of building area, and is used to prove the building has been constructed in compliance with governmental building energy codes.
In the ‘thermal energy model’ method, the set losses, values, and efficiencies are based upon the characteristics of each actual building component. Following clearly defined methods, this complicated model will include all energy systems and building materials, along with passive or renewable energy systems. The energy model simulation offers engineers and designers more freedom to exchange expensive systems or materials and to increase efficiencies in the building where it is most cost-effective.
In comparing thermal models, there is always the allowance for engineering discretion for trade-offs between systems and materials to achieve appropriate comfort levels, energy efficiency, and budget considerations. A ‘trade-off model’ can effectively show how some parts and installations are exceeding efficiency standards, while other building parts fall below. These sound engineering trade-offs can be developed in numerous ways:
- building envelope materials such as prefabricated insulated wall panels
- HVAC equipment substitutions, zoning and duct layout modifications
- BIM model design for facility management
- LED lighting and automation lighting control systems
- energy recovery systems to transfer existing heat losses to other spaces
- air sealing and moisture barrier solutions
- curtain wall systems or e-rated window shading for solar radiation
Thermal Modeling Services within BIM Framework
Building information system models (BIM) must have a thermal analysis model as the energy foundation during the early-stage design process. The calculation of the buildings energy demand is necessary to know the costs that will be required to meet that demand. As a minimum, the following information is required to establish an energy model to be used for future design input:
- building geometry and wall constructions
- thermal performance properties of walls and windows
- building occupancy including zones and occupant schedules
- geographical climate information including cloud coverage, temperatures, and sunlight
- HVAC and lighting systems installed services
The thermal model is used as a part of the total building performance model. BIM models are designed to use less water and energy, and while the initial cost may be greater, the daily energy costs will be substantially less than a non-BIM model. Additional parameters are generally included in a BIM thermal model, such as passive heating and cooling, and daylighting.
A BIM model is the optimum design process to manage thermal properties and energy utilization throughout the lifecycle of the structure. Using an outsourced 3D modeling and design firm to construct a BIM model will include not only energy utilization and management but also structural, architectural and lighting visualizations, automated construction collision checking, quantity take-offs and cost estimates, erection and construction management, and much more.
Partner with a firm that has extensive experience in 3D BIM services and thermal modeling services to capture your thermal environment and obtain thermal management solutions.