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Energy & Daylight Audits & Models

Energy and Daylight Audits & Modeling

Solar radiant flux on earth’s surface is an opportunity and an integral component of building energy consumption and generation. However, the optical and radiometric properties of solar radiation pose significant challenge to the selection of building fabric, both opaque and transparent components, in architectural design. Building energy modeling may be utilized to evaluate building energy consumption. The overall objective of any green design is to reduce energy consumption, and/or develop strategies to optimize energy consumption and offset the consumption through on-site energy generation or achieve Net Zero Energy status.
The Green Roundtable's staff utilizes state-of-the-art scientific tools to evaluate building envelope components, building HVAC systems and renewables. Additionally, as effective daylighting reduces electrical energy consumption, GRT staff is experienced in evaluating daylighting potential for a building to achieve optimum energy savings in buildings. It is essential to balance the energy flows in a building.
With this broad outlook, GRT provides the following advanced building performance services:

ASHRAE Commercial Building Energy Audits

GRT staff conducts ASHRAE Level I: Walk-through and Level II: Energy Survey and Engineering Analysis through,

  • Identifying possible no-cost/low-cost energy conservation measures. 
  • Developing comprehensive recommendations for energy efficiency improvements.
  • Reviewing of mechanical and electrical system design and operating methods, including existing operating and maintenance problems.
  • Evaluating the building energy flows – inputs and outputs based on energy use and preparing total annual energy use into end-use components. 

Building Systems Analysis

For New Construction, GRT staff assesses building systems to help building design professionals in,

  • Reviewing mechanical systems to optimize performance and minimize energy use.
  • Providing recommendations for high-performance building envelope design, shading optimization and balancing of daylight.

For Existing Buildings, GRT staff performs an extensive site assessment including,

  • Studying site components, building shell, and mechanical and electrical systems.
  • Reviewing existing building conditions and systems as they relate to energy and resource use
  • Developing recommendations for optimizing performance and minimizing energy use. 

Additional building systems services include,

  • Life-cycle costing assessment
  • Presenting the capital and operating costs of various building systems options and combinations.
  • Energy modeling services for USGBC LEED® rating systems, MA Stretch Code, IRS Tax Incentives, etc. 

Building Energy Modeling

GRT staff performs in-depth building energy modeling using project specifications, if available, or helps achieve optimized building thermal specifications through a process-oriented NZE approach. The building energy modeling process includes,

  • Compiling take–offs and modeling assumptions
  • Determining schedules of operation for various occupancies
  • Defining equipment power densities, air changes per hour, light power density, occupant density
  • Determining window-wall-ratio, floor-to-floor heights, plenum height, Solar Heat Gain Coefficient and U-factors for fenestration, etc.
  • Identification of various alternatives Energy Conservation Measures (ECMs).
  • Prioritizing ECMs based on the resultant saving. Eventually, all ECMs that yield satisfactory results of reasonable payback period will be combined into a single case. Several configurations of Base Case + ECMs need to be defined and simulated before arriving at the best or optimum combination of ECMs.
  • Reporting energy analysis calculations that will include a description of the project, a record of all modeling assumptions (set-points, material specifications, schedules, equipment and lighting densities, etc.), a description of ECMs, recommendations, specifications, and simulation results.

While developing the model, certain approximations are necessary such as, simplification of complicated contours and using thermal properties of the most closely related material for new or unspecified building materials. Attempts, though, would be made to minimize such compromises.

Daylighting Analysis

GRT staff performs comprehensive daylighting of building interiors for,

  • Evaluation of glazing parameters including location, type and size.
  • Development of photo-realistic renderings of complex interiors, including specular reflections using RADIANCE, an accurate backward particle-tracing algorithm.
  • Studying interaction between daylighting and thermal heat gain for glazing selection decision-making.

 

Request information by filling out this online form or contacting Colleen Soden at  colleen@greenroundtable.org or 617-374-3740 x102.