Energy demand attributable to the operation of supermarkets on-site is thought to be responsible for 1% of UK greenhouse gas emissions. In use data show a performance gap approaching a factor of three for overall energy use, with a gap of a factor of six in energy demand for heating. This performance gap indicates significant faults in the conventional modelling route. Current building regulations in the UK require the "building related" energy use of new commercial buildings to comply with particular requirements. Supermarket buildings are therefore modelled according to these protocols to establish their predicted energy demand. The impact on this predicted energy demand of the exclusion of process energy (eg for refrigeration) from these protocols is explored by modelling a supermarket retail floor with heat transfers related to refrigerated cabinets, and comparing the sensitivities of such models with those of models compliant with regulatory protocols. Whereas models compliant with regulatory protocols indicate an advantage of limiting the level of insulation and airtightness, and allowing stratification, to facilitate heat loss through the store envelope; models that include heat transfers around the refrigerated cabinets are found to show that energy demand may be decreased by up to 40% by doubling both insulation and airtightness, and by destratification. This will, however, only apply if rates of air change in buildings in use match those modelled. This shows the importance of including heat transfers around refrigerated cabinets in design modelling, so that appropriate decisions may be taken with respect to building envelope parameters. Compliance modelling protocols should be changed to reflect this. In order to facilitate this change and enable modelling of refrigerated cabinets within a compliance model through a few simple inputs, a set of data and associated algorithms is derived and offered for inclusion in compliance modelling tools.

Climate change projections estimate a rise of approximately 3 °C by the 2080‘s for most of the UK (under a medium emissions scenario at 50% probability level, 1961-1990 baseline). Warming is of particular concern for urban areas due to the issues of urban densification and the Urban Heat Island (UHI) effect. To combat warming, one adaptation strategy that has been suggested for urban areas is increasing the proportion of greenspace, such as parks, gardens, street tree plantings, and green roofs. While a number of studies have investigated the cooling effect of greenspace in terms of park size, proximity to a park, or area covered by tree canopy, little is yet known about the specific types of greenspace that contribute to its cooling effectiveness and how this relates to building energy demand. This thesis employs an interdisciplinary approach to model fine-scale changes to greenspace for a temperate northern UK city, linking the resulting microclimate changes to building energy consumption in commercial buildings. Using the urban microclimate model ENVI-met, two study areas (one urban one suburban) were modelled with seven different greenspace scenarios (a base case representing current field conditions, +5% new trees, +5% mature trees, +5% hedges, addition of a green roof on the largest building, changing all current greenspace to grass only, and changing all current greenspace to asphalt only) for a summer day in July 2010. The models were calibrated based on measured air temperature data and then analysed for microclimate changes due to each greenspace scenario. Both the modelled and measured microclimate data were then used to inform a series of building energy models using IES-VE 2012 for three commercial building types, estimating summer cooling and winter heating trade-offs due to greenspace effects. For the most effective scenario of adding 5% mature trees to the urban case study, the microclimate modelling estimates a maximum hourly air temperature reduction of nearly 0.7 °C at 5 pm and surface temperature reductions up to 1.7 °C at 3 pm. In the suburban case study, a 5% increase in mature deciduous trees can reduce mean hourly surface temperatures by 1 °C between 10 am and 5 pm, while the worst case scenario of replacing all current vegetation (20% of the study area) with asphalt results in increased air temperature of 3.2 °C at mid-day. The building energy modelling estimates a reduction of 2.7% in July chiller energy due to the combination of reduced UHI peak hours and eight additional trees (four on the north side and four on the south side) of a three-storey shallow plan building. These energy savings increase to 4.8% under a three-day period of peak UHI conditions. While winter boiler energy usage shows large reductions for a building in an urban location with a low proportion of greenspace (as compared to a suburban location), this benefit is marginal when analysed in terms of carbon trade-offs between summer cooling and winter heating requirements.

No description available.

In this dissertation, an increased thermal capacitance (ITC) and thermal storage management (TSM) system was simulated to reduce building energy consumption, specifically energy related to heating, cooling and domestic hot water. An increased thermal capacitance allows phase shift and amplitude reduction of heat flow fluctuations associated with the building’s internal temperature response due to weather. An adaptive allocation and control of the added capacitance through TSM significantly improves the benefits of the extra capacitance. This dissertation was conducted in three parts: (1) a first-order analysis of the ITC/TSM applied to a micro-building; (2) a transient simulation of the ITC/TSM with PCM implementation for tank volume control; and (3) a parameter study on the ITC/TSM system with added complexities such as the inclusion of DHW and a multiple story residential building. The first-order analysis was used for transient simulation comparison, as simple models are much more suitable for real time implementation in actual control systems. A first order study on a small residential building is also used to establish the merit of the ITC/TSM concept before integrating into a more complex analysis. This study determined that the ITC/TSM could potentially provide savings but required a very large thermal mass. The ITC/TSM system was then coupled with phase change materials (PCMs), which enable thermal energy storage volume reduction. The transient energy modeling software, TRNSYS, is used to simulate the building’s thermal response and energy consumption, as well as the ITC/TSM system and controls. Four temperature-controlled operating regimes are used for the ITC/TSM operations: building shell circulation, heat exchanger circulation, solar panel circulation, and storage. After this, 125 simulations were conducted to design and optimize the ITC/TSM. The three parameters of interest were: tank volume size, solar panel size, and mass flowrate. Domestic hot water usage was also included as another energy savings opportunity. Results for the parameter study showed that savings are optimized when the solar panel and the hot water tank are size together. If they are not sized simultaneously, the temperature of the large thermal capacitance is not adequately controlled. For all simulations conducted in the parameter study, the building energy usage was reduced significantly.

An energy analysis was performed on the Texas A & M University at Qatar building in Doha, Qatar. The building and its HVAC systems were modeled using EnergyPlus. Building chilled water and electrical data were collected to validate the computer simulation. The simulated monthly electricity consumption was within plus/minus 5 percent of the metered building data. Ninety-five percent of simulated hourly electricity data in a day were within plus/minus 10 percent of metered data. Monthly chilled water demand was within plus/minus 18 percent of measurements, and simulated monthly demand was correlated to metered monthly values with an R-squared correlation coefficient of 0.95. Once the simulation was verified with the metered data, an optimization of the building's HVAC systems was performed. Better utilizing the building's variable speed fans at part loads showed potential annual electricity savings of 16 percent over the base case, with another 22 percent savings in chilled water energy. After converting chilled water savings to equivalent chiller electricity savings, the potential utility cost savings over the base case were found to be $90,000/yr at local utility rates. Reducing outdoor air intake to ASHRAE indoor air quality minimums yielded an additional 17 percent in potential chilled water savings and brought total monetary savings over the base case to $110,000/yr. Using a dedicated outside air system to precisely control individual zone ventilation showed potential for an additional 12 percent chilled water savings and $14,000 in yearly utility savings, while also eliminating cases of under-ventilation. A hypothetical retrofit of fan powered terminal units (FPTU's) resulted in energy savings only at very low minimum flow rates, below ventilation standards. Savings were never more than 20 percent over the no-fan case. Series FPTU's showed no savings at any flow setting and negligible difference was found between ECM and SCR motor control. Finally, the dependence on climate of each improvement was studied. Simulations were run in the relatively milder climates of Houston and Phoenix and compared to those found for Doha. It was found that variable speed fan operation is a more cost effective option for milder climates, while outside air control is more cost effective in extreme hot and humid climates such as Doha. Future study is needed to make the FPTU model valid for different climates and flow ranges.

No description available.

Current designs of high performance buildings utilize hourly building energy simulations of complex, interacting systems. Such simulations need to quantify the benefits of numerous features including: thermal mass, HVAC systems and, in some cases, special features such as active and passive solar systems, photovoltaic systems, and lighting and daylighting systems. Unfortunately, many high performance buildings today do not perform the way they were simulated. One potential reason for this discrepancy is that designers using the simulation programs do not understand the analysis methods that the programs are based on and therefore they may have unreasonable expectations about the system performance or use. The purpose of this study is to trace the origins of a variety of simulation programs and the analysis methods used in the programs to analyze high performance buildings in the United States. Such an analysis is important to better understand the capabilities of the simulation programs so they can be used more accurately to simulate the performance of an intended design. The goal of this study is to help explain the origins of the analysis methods used in whole-building energy simulation, solar system analysis simulation or design, and lighting and daylighting analysis simulation programs. A comprehensive history diagram or genealogy chart, which resolves discrepancies between the diagrams of previous studies, has been provided to support the explanations for the above mentioned simulation programs.

The built environment is responsible for a large portion of total energy use and emissions. A large portion comes from the buildings themselves, but also the transportation system to move people around. As global populations grow, and more people migrate to cities, it is critically important that new city growth is done in the most sustainable manner possible. The typical North American pattern of urban growth is urban sprawl, characterized by single use type zoning, low density, transportation system dominated by personal vehicles, and poor public transit. Urban sprawl has numerous downsides, including poorer energy efficiency in buildings and infrastructure, more congestion and higher emission from vehicles, as well as many negative health effects. This thesis presents the concept of a Mothership, a large, high-density mixed-use building designed to combat urban sprawl and minimize energy use and emissions of the built environment. A mothership is designed to provide all the amenities and housing of a typical suburb for 10,000 people. The analysis in this thesis employ building simulation tools to model various mothership designs and analyse the operational and embodied energy and carbon emissions for each design, and compare it to base cases of more traditional building use types such as single detached homes, and different types of apartment buildings. The effect of high-performance building envelopes and other building materials on operational and embodied energy and emissions are analysed. A multi objective optimization analysis is performed to determine which technologies and combinations of technologies provide the lowest cost solution to meet the mothership’s energy demands while also minimizing emissions. The mothership’s effect on transportation emissions is also investigated. The building’s mixed-use nature allows trips to be satisfied within walking distance in the building. The high concentration of people makes for a good anchor load for public transportation, so the emissions reductions of implementing a bus rapid transit system from the mothership to the central business district is estimated. To reduce transportation emissions further, the effect of an electric car share fleet for mothership residents use is also quantified. The energy system of a mothership is optimized, along with base cases of single detached homes, under numerous scenarios. These scenarios are designed to explore how the energy system changes in an attempt to answer a series of research questions. Some of the measures explored are a high carbon tax, net metering, and emissions limits of net zero, and negative emissions with two different electrical grid carbon intensities. Results showed that a highly insulated, timber framed mothership can achieve very high reductions in energy use and emissions. Overall it showed reductions of 71%, 73%, and 74% in operational energy, embodied energy and embodied carbon respectively, over a baseline case of single detached homes. It was estimated that transportation emissions could be reduced by 58% through the mixed-use development reducing the number of trips and electrically powered transportation vehicles and bus rapid transit. This gives a combined total emissions reduction of 61%. Energy system optimization showed that the mothership design in achieved far lower costs and emissions (4 and 8.7 times lower respectively) than the base case of single detached homes. Of the mothership cases examined, the most expensive case was the one which had a carbon tax, with an annualized cost of $4.3 million. The case with the lowest annualized cost was one with, among other factors, a net zero carbon emissions restriction (annualized cost of $3.08 million. Many of the cases had negative operating costs due to the sale of renewable energy or carbon credits. This illustrates that the integration of renewable energy technologies is not only beneficial for reducing emissions but can also act as an income pathway for energy systems. / Graduate

Being located in subtropical climates, the cooling energy accounts for a huge percentage of the total power consumption, and has become the major cause for power shortages. Therefore, building energy conservation strategies has become the major remedy to tackle this problem. In this study, the building energy performance certificate evaluation system has been established, in referencing the European communities systems, while integrating the financial and consumers factors to establish the building labeling system in Taiwan.

A methodology to develop an easy-to-use toolkit for the preliminary design of high performance schools in hot and humid climates was presented. The toolkit proposed in this research will allow decision makers without simulation knowledge easily to evaluate accurately energy efficient measures for K-5 schools, which would contribute to the accelerated dissemination of energy efficient design. For the development of the toolkit, first, a survey was performed to identify high performance measures available today being implemented in new K-5 school buildings. Then an existing case-study school building in a hot and humid climate was selected and analyzed to understand the energy use pattern in a school building and to be used in developing a calibrated simulation. Based on the information from the previous step, an as-built and calibrated simulation was then developed. To accomplish this, five calibration steps were performed to match the simulation results with the measured energy use. The five steps include: 1) Using an actual 2006 weather file with measured solar radiation, 2) Modifying lighting & equipment schedule using ASHRAE's RP-1093 methods, 3) Using actual equipment performance curves (i.e., scroll chiller), 4) Using the Winkelmann's method for the underground floor heat transfer, and 5) Modifying the HVAC and room setpoint temperature based on the measured field data. Next, the calibrated simulation of the case-study K-5 school was compared to an ASHRAE Standard 90.1-1999 code-compliant school. In the next step, the energy savings potentials from the application of several high performance measures to an equivalent ASHRAE Standard 90.1-1999 codecompliant school. The high performance measures applied included the recommendations from the ASHRAE Advanced Energy Design Guides (AEDG) for K- 12 and other high performance measures from the literature review as well as a daylighting strategy and solar PV and thermal systems. The results show that the net energy consumption of the final high performance school with the solar thermal and a solar PV system would be 1,162.1 MMBtu, which corresponds to the 14.9 kBtu/sqft-yr of EUI. The calculated final energy and cost savings over the code compliant school are 68.2% and 69.9%, respectively. As a final step of the research, specifications for a simplified easy-to-use toolkit were then developed, and a prototype screenshot of the toolkit was developed. The toolkit is expected to be used by non-technical decision-maker to select and evaluate high performance measures for a new school building in terms of energy and cost savings in a quick and easy way.