Numerical modelling of thermal comfort in non-uniform environments using real-time coupled simulation models

This research aimed to test and validate the only existing real-time coupled model of human thermal comfort by comparing simulation results and measured data for a number of different realistic non-uniform scenarios. This model incorporates detailed and realistic human figures in CFD, coupled with the IESD-Fiala model which enables the reaction of human occupants and their influence on the environment by heat and mass transfer to be modelled. A set of likely configurations have been created in an environmental chamber. Typical furniture, a thermal manikin and a portable fan have been used to generate non-uniform controlled environments, and detailed measurements have been taken. The same configurations have been modelled using the coupled model. The initial results highlight that this coupled model can effectively predict human thermal comfort in non-uniform environments, being able to represent dynamic conditions around the body in real time. Further work is addressing more complex configurations

Development of the ASHRAE Global Thermal Comfort Database II

Recognizing the value of open-source research databases in advancing the art and science of HVAC, in 2014 the ASHRAE Global Thermal Comfort Database II project was launched under the leadership of University of California at Berkeley’s Center for the Built Environment and The University of Sydney’s Indoor Environmental Quality (IEQ) Laboratory. The exercise began with a systematic collection and harmonization of raw data from the last two decades of thermal comfort field studies around the world. The ASHRAE Global Thermal Comfort Database II (Comfort Database), now an online, open-source database, includes approximately 81,846 complete sets of objective indoor climatic observations with accompanying “right-here-right now” subjective evaluations by the building occupants who were exposed to them. The database is intended to support diverse inquiries about thermal comfort in field settings. A simple web based interface to the database enables filtering on multiple criteria, including building typology, occupancy type, subjects’ demographic variables, subjective thermal comfort states, indoor thermal environmental criteria, calculated comfort indices, environmental control criteria and outdoor meteorological information. Furthermore, a web-based interactive thermal comfort visualization tool has been developed that allows end-users to quickly and interactively explore the data

Feasibility of coupling a thermal/optical carbon analyzer to a quadrupole mass spectrometer for enhanced PM2.5 speciation

A thermal/optical carbon analyzer (TOA), normally used for quantification of organic carbon (OC) and elemental carbon (EC) in PM2.5 (fine particulate matter) speciation networks, was adapted to direct thermally evolved gases to an electron impact quadrupole mass spectrometer (QMS), creating a TOA-QMS. This approach produces spectra similar to those obtained by the Aerodyne aerosol mass spectrometer (AMS), but the ratios of the mass to charge (m/z) signals differ and must be remeasured using laboratory-generated standards. Linear relationships are found between TOA-QMS signals and ammonium (NH4+), nitrate (NO3-), and sulfate (SO42-) standards. For ambient samples, however, positive deviations are found for SO42-, compensated by negative deviations for NO3-, at higher concentrations. This indicates the utility of mixed-compound standards for calibration or separate calibration curves for low and high ion concentrations. The sum of the QMS signals across all m/z after removal of the NH4+, NO3-, and SO42- signals was highly correlated with the carbon content of oxalic acid (C2H2O4) standards. For ambient samples, the OC derived from the TOA-QMS method was the same as the OC derived from the standard IMPROVE_A TOA method. This method has the potential to reduce complexity and costs for speciation networks, especially for highly polluted urban areas such as those in Asia and Africa.Implications: Ammonium, nitrate, and sulfate can be quantified by the same thermal evolution analysis applied to organic and elemental carbon. This holds the potential to replace multiple parallel filter samples and separate laboratory analyses with a single filter and a single analysis to account for a large portion of the PM2.5 mass concentration

Benefit-Cost Analysis in Environmental, Health, and Safety Regulation: A Statement of Principles

Benefit-cost analysis can play a very important role in legislative and regulatory policy debates on improving the environment, health, and safety. It can help illustrate the tradeoffs that are inherent in public policymaking as well as make those tradeoffs more transparent. It can also help agencies set regulatory priorities. Benefit-cost analysis should be used to help decisionmakers reach a decision. Contrary to the views of some, benefit-cost analysis is neither necessary nor sufficient for designing sensible public policy. If properly done, it can be very helpful to agencies in the decisionmaking process. Decisionmakers should not be precluded from considering the economic benefits and costs of different policies in the development of regulations. Laws that prohibit costs or other factors from being considered in administrative decisionmaking are inimical to good public policy. Currently, several of the most important regulatory statutes have been interpreted to imply such prohibitions. Benefit-cost analysis should be required for all major regulatory decisions, but agency heads should not be bound by a strict benefit-cost test. Instead, they should be required to consider available benefit-cost analyses and to justify the reasons for their decision in the event that the expected costs of a regulation far exceed the expected benefits. Agencies should be encouraged to use economic analysis to help set regulatory priorities. Economic analyses prepared in support of particularly important decisions should be subjected to peer review both inside and outside government. Benefits and costs of proposed major regulations should be quantified wherever possible. Best estimates should be presented along with a description of the uncertainties. Not all benefits or costs can be easily quantified, much less translated into dollar terms. Nevertheless, even qualitative descriptions of the pros and cons associated with a contemplated action can be helpful. Care should be taken to ensure that quantitative factors do not dominate important qualitative factors in decisionmaking. The Office of Management and Budget, or some other coordinating agency, should establish guidelines that agencies should follow in conducting benefit-cost analyses. Those guidelines should specify default values for the discount rate and certain types of benefits and costs, such as the value of a small reduction in mortality risk. In addition, agencies should present their results using a standard format, which summarizes the key results and highlights major uncertainties.

Is There a Role for Benefit-Cost Analysis in Environmental, Health, and Safety Regulation?

Benefit-cost analysis has a potentially important role to play in helping inform regulatory decision-making, although it should not be the sole basis for such decision-making. This paper offers eight principles on the appropriate use of benefit-cost analysis.Environment, Health and Safety, Regulatory Reform

Coupling a model of human thermoregulation with computational fluid dynamics for predicting human-environment interaction

This paper describes the methods developed to couple a commercial CFD program with a multi-segmented model of human thermal comfort and physiology. A CFD model is able to predict detailed temperatures and velocities of airflow around a human body, whilst a thermal comfort model is able to predict the response of a human to the environment surrounding it. By coupling the two models and exchanging information about the heat transfer at the body surface the coupled system can potentially predict the response of a human body to detailed local environmental conditions. This paper presents a method of exchanging data, using shared files, to provide a means of dynamically exchanging simulation data with the IESD-Fiala model during the CFD solution process. Additional code is used to set boundary conditions for the CFD simulation at the body surface as determined by the IESD-Fiala model and to return information about local environmental conditions adjacent to the body surface as determined by the CFD simulation. The coupled system is used to model a human subject in a naturally ventilated environment. The resulting ventilation flow pattern agrees well with other numerical and experimental work

More Than Forty Prominent Economists Urge Supreme Court to Allow EPA to Consider Costs and Consequences of Clean Air Regulations

More than forty prominent economists filed a Friend of the Court brief with the Supreme Court, asking the justices to overturn a lower court ruling that the Environmental Protection Agency (EPA) may not take into account the costs of regulations when setting standards under the Clean Air Act. Calling the lower court ruling "economically unsound," the economists argued that the EPA "should be allowed to consider explicitly the full consequences" of regulatory decisions, including costs, benefits, and any other relevant facts. In their Amici Curiae brief, the economists contended that the "plain aim" of the Clean Air Act "is protecting the public health&quo.t; That aim, they said, "is unlikely to be achieved without, at least, an implicit balancing of benefits and costs." The Supreme Court filing was organized by the American Enterprise Institute-Brookings Joint Center for Regulatory Studies. The bipartisan group of economists signing the brief included three Nobel laureates, seven former chairmen of the President's Council of Economic Advisers, and two former directors of the White House Office of Management and Budget. The case, American Trucking Association v. Carol M. Browner, Administrator of the Environmental Protection Agency , was appealed to the Supreme Court after a Federal Court in Washington D.C. ruled that the EPA was not permitted to consider costs in setting regulatory standards for enforcing the Clean Air Act. "We believe it would be imprudent for the EPA to ignore costs totally, particularly given their magnitude in this case," the economists stated in the brief. "The EPA estimates that those [clean air] standards could cost on the order of $50 billion annually." The brief argued, "Not considering costs makes it difficult to set a defensible standard, especially when there is no threshold below which health risks disappear." Ignoring costs, the economists said, "could lead to a decision to set the standard at zero pollution," which would threaten "the very economic prosperity on which public health primarily depends." The economists declared: "The importance of this issue cannot be overstated. Both direct benefits and costs of environmental, health, and safety regulations are substantial, estimated to be several hundred billion dollars annually." If the Supreme Court overturns the lower court ruling and allows the EPA to consider costs in establishing clear air regulations, the brief argued, it would be "a historic moment in the making of regulatory policy."Environment, Other Topics

Integrated Economic and Climate Modeling

This survey examines the history and current practice in integrated assessment models (IAMs) of the economics of climate change. It begins with a review of the emerging problem of climate change. The next section provides a brief sketch of the rise of IAMs in the 1970s and beyond. The subsequent section is an extended exposition of one IAM, the DICE/RICE family of models. The purpose of this description is to provide readers an example of how such a model is developed and what the major components are. The final section discusses major important open questions that continue to occupy IAM modelers. These involve issues such as the discount rate, uncertainty, the social cost of carbon, the potential for catastrophic climate change, algorithms, and fat-tailed distributions. These issues are ones that pose both deep intellectual challenges as well as important policy implications for climate change and climate-change policy