On the Benefits of Whole-building IAQ, Ventilation, Infiltration, and Energy Analysis Using Co-simulation between CONTAM and EnergyPlus

Publicly available tools to perform whole-building simulation of indoor air quality, ventilation, and energy have been available for several decades. Until recently, these tools were developed in isolation, such as the whole-building contaminant transport and airflow analysis tool, CONTAM, developed by the National Institute of Standards and Technology (NIST) and the whole-building energy analysis tool, EnergyPlus, developed by the U.S. Department of Energy (DOE). The ability to couple these tools during runtime has been implemented through co-simulation, enabling improved analysis of the interdependent effects of temperature and airflow on contaminant transport and energy use on a whole-building scale. This presentation will include the development of a set of coupled reference building models for the purposes of evaluating the potential benefits of using co-simulation between CONTAM and EnergyPlus. A set of Residential Prototype Building Models available from DOE has been modified by NIST and utilized to demonstrate the coupling process and the benefits of this coupling with respect to IAQ and energy analysis, and to evaluate multiple whole-building simulation methods related to infiltration, ventilation, and occupant exposure. These methods include an original EnergyPlus prototype model, the original model with NIST-based infiltration correlations, co-simulation between EnergyPlus and CONTAM, and stand-alone CONTAM simulations. Potential benefits will be explored related to the ability of co-simulation to address the effects of variations in building typology and ventilation system performance on contaminant transport results while leveraging the capabilities of whole-building energy analysis.

Efficient Envelope Designs to Maximize Residential Cooling Energy Savings in Bangkok Neighborhoods

Architectural design can significantly improve home energy-efficiency. New energy-saving techniques are regularly proposed; however, integrating all design parameters into the energy simulation specific knowledge and is time-consuming, making it difficult for non-experts in building energy analysis. This present study investigates the impact of envelope designs on household cooling energy consumption in housing complexes located in Bangkok neighborhood areas. The study selects a representative house and identifies a range of envelope designs, including thermal properties of exterior walls and roof, painted color, length of roof eaves, and window-to-wall ratio (WWR). The Latin hypercube method randomly generates two hundred sets of design scenarios based on those design parameters. The eQuest model is used to perform analysis of household cooling energy consumption for four orientations, and the simulation results are validated. The standardized regression coefficient (SRC) is used to determine a strong correlation between design parameters and cooling energy consumption in detached houses. The results reveal that improving a window’s solar heat gain coefficient (SHGC), wall painted color, wall u-value, and length of roof eaves could reduce energy consumption by up to 19.7 percent. The WWR and building orientation were found to have only a small impact on household cooling energy consumption, especially for a square-shaped house. The results provide designers and non-professional a simple design guideline to improve the energy efficiency of their home designs.

Green roofs in building retrofits: outdoor microclimate benefits and energy savings

The impact of green roof retrofits on the local microclimate and energy consumption of a building is investigated. This research is based on a case study of Kerr Hall located on the Ryerson University campus in Toronto. The software ENVI-met is used to simulate the microclimate while EnergyPlus is used for the building energy analysis. Results indicate that increasing the leaf area index (LAI) of the green roof leads to increased cooling effect up to 0.4 degrees C during the day at pedestrian-level; however, more significant cooling is attained at the rooftop-level. The addition of the green roof reduced both the heating and cooling demands and improved indoor comfort levels. Energy demand reductions up to 3% were obtained with the green roof retrofits with the biggest contribution form from reduction in heating on the top floor. Increasing the soil depth had a larger impact on the energy consumption compared to increasing the LAI.

Green roofs in building retrofits: outdoor microclimate benefits and energy savings

The impact of green roof retrofits on the local microclimate and energy consumption of a building is investigated. This research is based on a case study of Kerr Hall located on the Ryerson University campus in Toronto. The software ENVI-met is used to simulate the microclimate while EnergyPlus is used for the building energy analysis. Results indicate that increasing the leaf area index (LAI) of the green roof leads to increased cooling effect up to 0.4 degrees C during the day at pedestrian-level; however, more significant cooling is attained at the rooftop-level. The addition of the green roof reduced both the heating and cooling demands and improved indoor comfort levels. Energy demand reductions up to 3% were obtained with the green roof retrofits with the biggest contribution form from reduction in heating on the top floor. Increasing the soil depth had a larger impact on the energy consumption compared to increasing the LAI.