Category: Publications, Presentations, Seminar Notes

In my earlier columns, I tried to explain the concept of uncertainty analysis and also draw the attention of the industry to the advantages of performing probabilistic energy modeling. One of the most valuable complementary tools to uncertainty analysis is sensitivity analysis. Terje Aven in his book, Foundation of Risk Analysis,1 gives the following definition for sensitivity analysis: “A sensitivity analysis is a study of how sensitive the risk is with respect to changes in input parameter of risk model.” more

Health-care design evolves constantly, reflecting improvements and advancements in surgical techniques, equipment (such as MRIs and robotic surgical equipment), clinical practices, hospital design trends, energy efficiency, sustainable design, and other factors. Ventilation for health-care facilities must change to be aligned with the changing needs of health-care facilities design, patients, surgeons, clinical staff, and visitors. more

Building an energy-efficient building often begins with an energy (cost) comparison between a design building and an imaginary baseline building as defined in ASHRAE/IES Standard 90.1, Appendix G. Even though this method has contributed to higher performance of buildings and systems, I believe we can do better than that. more

When one thinks of critical infrastructures, some come quickly to mind: the water system, the power grid, the Internet, dams, bridges, roads, air and rail transportation to name a few. Commercial buildings may not occur to the average individual as critical infrastructure, but they are considered as such by the Department of Homeland Security (DHS) and ASIS International. If we think about the impact of the 9/11 attack on the Twin Towers, we understand why. The attack on the Twin Towers cost nearly 2,600 people their lives, and launched the United States into a long term war on terror that has increased the national debt approximately 1.5 trillion dollars.1  more

In my November column, I discussed the necessity of performing a probabilistic energy modeling process instead of a deterministic one for an ASHRAE/IES Standard 90.1, Appendix G, design building. To be able to run a probabilistic energy model, the first step is to develop a tolerance margin library for all the construction material that would be used in constructing a building and for its associated equipment. more

Uncertainty analysis is the process of changing simulation model input parameters in a small margin of possible occurrences and observing how simulation output can be affected (output probability distribution). That is the basic difference between a deterministic simulation and a probabilistic (uncertain) simulation. Uncertainty analysis is a strong tool for modelers and those who use modeling results to make well-informed decisions. more

Most HVAC design engineers use an array of sophisticated software calculation and modeling tools for load calculations and energy analysis. These tools offer almost total flexibility for the engineer to define physical arrangement, thermal parameters, operating schedules, internal loads and zoning. To achieve that flexibility, the input parameters are extensive and time consuming. more

Architects have long embraced BIM, and software developers are moving to add mechanical, electrical and plumbing to the models. ASHRAE Technical Committee 4.1, Load Calculation Data and Procedures, prepared a seminar for the 2010 ASHRAE Annual Conference to examine the state-of-the-art for using building information modeling (BIM) for load calculations, including methods of extracting data from the BIM model for import into traditional stand-alone calculation programs and use of built-in “native” BIM load calculation software. This article addresses native BIM load calculations only, although lessons learned regarding interoperability and data definition apply to both approaches.  more

ANSI/ASHRAE/ASHE Standard 170-2008, Ventilation of Health Care Facilities, can be adopted by authorities for health care facility construction and private national organizations such as the Facilities Guidelines Institute (FGI). In 2010, FGI incorporated Standard 170- 2008 as Part Six of its Guidelines for Design and Construction of Health Care Facilities.1 This includes all addenda, present and future, issued by ASHRAE. The Joint Commission, federal agencies and authorities in 42 states use the Guidelines either as a code or a reference standard when reviewing, approving, and financing projects or when surveying, licensing, certifying or accrediting newly constructed facilities, according to FGI.  more

Specialty systems include many of the low-voltage systems that comprise the tools necessary for information professionals to produce work. Many applications such as e-mail, messaging, telephony, security systems and building environmental controls depend on the LAN and WAN and require a robust combination of physical hardware and logical configuration to operate correctly. As we learned by watching the heating, ventilating and air conditioning (HVAC) industry, benefits can be realized by more closely involving the design team, the contractor and the owner during the implementation phase to ensure that systems operate as intended and can prove themselves fully during a performance evaluation. more