Energy effectiveness of duct sealing and insulation in two multifamily buildings

Energy losses from forced air distribution systems have a significant impact on the energy efficiency of buildings. Little work has been done to quantify these losses in apartment buildings. In this paper the authors will discuss field measurements made on four forced air heating systems to evaluate the duct system energy losses to unconditioned basements. The apartments were heated by natural gas furnaces located in the basements. The systems had bare sheet metal ductwork exposed to the basement conditions. The pre-retrofit measurements were made on the systems after sealing large easily visible leaks. The post-retrofit measurements were made after wrapping the ducts in foil backed glass fiber insulation and additional leak sealing. Only the sections of duct exposed to the basement were retrofitted because only these sections were accessible. This study examines the potential energy savings for this type of limited retrofit. The energy losses were separated into leakage and conduction terms. Leakage measurements were made using register flowhood techniques. Conduction losses were estimated by measuring temperatures in the plenums and at the registers. Analysis of the measurements has shown typical reduction in leakage flow due to duct sealing of about 40%. The reduction in leakage translated into a reduction in energy consumption of about 10%

Information diffusion in the U.S. real estate investment trust market

This study examines the information diffusion process in the U.S. Real Estate Investment Trust (REIT) market with a focus on the impacts of changing market environments, information supply, and information demand on the lead-lag effect. The results suggest that a significant lead-lag relationship exists between the lagged returns of big REITs and the current returns of small REITs. This relationship has slightly decreased along with policy and environment changes that occurred in the U.S. REIT market during the study period from 1986 to 2012, while still remaining significant in the most recent REIT market. The process of information diffusion is becoming unstable in recent years and the reverse lead-lag effect from small REITs to big REITs is observed especially when REIT market liquidity and return volatility are high. The lead-lag effect among REITs is driven largely by slow adjustment to negative information, which is magnified by a lack of information supply, especially as demand for such information increases. Finally, information flow from REITs with more media coverage to those with less media coverage becomes even more sluggish than the information flow from big REITs to small REITs

Design indicators for better accommodation environments in hospitals: inpatients’ perceptions

This is an Author's Accepted Manuscript of an article published in Intelligent Buildings International, 2012, [© Taylor & Francis], available online at: http://www.tandfonline.com/doi/abs/10.1080/17508975.2012.701186Several studies have found an association between the physical environment and human health and wellbeing that resulted in the postulation of the idea of evidence-based and patient-centred design of healthcare facilities. The key challenge is that most of the underpinning research for the evidence base is context specific, the use of which in building design is complex, mainly because of the difficulties associated with the disaggregation of findings from the context. On the other hand, integrating patients’ perspectives requires an understanding of the relative importance of design indicators, which the existing evidence base lacks to a large extent. This research was aimed at overcoming these limitations by investigating users’ perception of the importance of key design indicators in enhancing their accommodation environments in hospitals. A 19-item structured questionnaire was used to gather inpatients' views on a 5-point scale, in two Chinese hospitals. A principal component analysis (PCA) resulted in five constructed dimensions with appropriate reliability and validity (Cronbach’s alpha=0.888). The item, design for cleanliness, was ranked as most important, closely followed by environmental and safety design indicators. The item, entertainment facilities, was ranked lowest. The indicator, pleasant exterior view had the second lowest mean score, followed by the item, ability to customise the space. Age, accommodation type and previous experience of hospitalisation accounted for statistically significant differences in perceptions of importance of various constructed design dimensions

The DOE Slide Rule: An Energy Conservation Estimating Tool for Homebuilders

How much insulation should be placed in the ceiling of a home? Which furnace is the best investment? Is reflective glazing a marketable option? The DOE slide rules and accompanying guides are designed to help answer such questions by providing a way to measure the impact on home energy use of a variety of energy conservation options. The whole kit is designed to be accurate and easy to use. It provides guidance on energy efficient construction practices, and a means to quantify them by using the slide rules. An economic analysis is also suggested. The work aims at transferring high level research to non-technical users: homeowners, builders and lenders

Effectiveness of Duct Sealing and Duct Insulation in Multi-Family Buildings. Final Report

This research investigated the cost-effectiveness of sealing and insulating the accessible portions of duct systems exposed to unconditioned areas in multifamily housing. Airflow and temperature measurements were performed in 25 apartments served by 10 systems a 9 multi-family properties. The measurements were performed before and after each retrofit, and included apartment airflow (supply and return), duct system temperatures, system fan flow and duct leakage area. The costs for each retrofit were recorded. The data were analyzed and used to develop a prototypical multifamily house. This prototype was used in energy simulations (DOE-2.1E) and air infiltration simulations (COMIS 2.1). The simulations were performed for two climates: New York City and Albany. In each climate, one simulation was performed assuming the basement was tight, and another assuming the basement was leaky. Simulation results and average retrofit costs were used to calculate cost-effectiveness. The results of the analysis indicate that sealing leaks of the accessible ductwork is cost-effective under all conditions simulated (simple payback was between 3 and 4 years). Insulating the accessible ductwork, however, is only cost-effective for buildings with leaky basement, in both climates (simple paybacks were less than 5 years). The simple payback period for insulating the ducts in buildings with tight basements was greater than 10 years, the threshold of cost-effectiveness for this research. 13 refs., 5 figs., 27 tabs

The Optimal Timing of Strategic Action – A Real Options Approach

The possibility of a first-mover advantage arises in a variety of strategic choices, including product introductions, business start-ups, and mergers and acquisitions. The strategic management literature reflects ambiguity regarding the likelihood that a first mover can or will capture additional value. This paper uses a real options approach to address the optimal timing of strategic moves. Previous studies have modeled real options using either a perpetual or a European financial option. With these models, a strategic choice could only be made either without respect to a time frame (perpetual) or at a fixed point in time (European option.) Neither case is realistic. Companies typically have strategic options with only a limited time frame due to market factors, but companies may choose to act at any time within that constraint. To reflect this reality, we adapt a method for valuing an American financial option on a dividend paying stock to the real options context. The method presented in this paper proposes a solution for the optimum value for a project that should trigger a strategic choice, and highlights the value lost by not acting optimally. We use simulation results to show that the time frame available to make a strategic choice has an important effect on both the project value for when action should be taken, as well as on the value of waiting to invest at the optimal time. The results presented in this paper help to clarify the ambiguity that is found in the strategic management literature regarding the possibility of obtaining a first-mover advantage. Indeed, a first mover that acts sub-optimally could incur losses or at least not gain any advantage. A first mover that waits to invest at the right time based on the superior information supplied by models based on real options could be better positioned to obtain the benefits that might come from the first move.Możliwość uzyskania przewagi “pierwszego ruchu” pojawia się w kontekście różnorodnych decyzji o charakterze strategicznym, takich jak wprowadzenie na rynek nowego produktu, podjęcie nowej działalności gospodarczej czy też fuzje i przejęcia. Literatura z zakresu zarządzania strategicznego nie charakteryzuje w sposób jednoznaczny prawdopodobieństwa uzyskania dodatkowej wartości z tytułu realizacji “pierwszego ruchu”. Niniejsza praca proponuje podejście oparte o metodologię wyceny realnych opcji (ang. real options approach) dla wyznaczenia optymalnego momentu dla realizacji strategicznego posunięcia (realizacji projektu inwestycyjnego). W odróżnieniu od proponowanych w literaturze podejść z zakresu wyceny realnych opcji, autorzy proponują metodę opartą o wycenę opcji finansowej typu Amerykańskiego. Metoda, oparta o znany model aproksymacyjny zaproponowany przez Barone-Adesi i Whaley (1987), pozwala na wyznaczenie wartości projektu w terminie optymalnym dla jego realizacji i wartości wstrzymania się z podjęciem decyzji o realizacji projektu do terminu optymalnego (wartość opcji “wait and see”). Rezultaty symulacji wskazują na istotną rolę długości horyzontu czasowego, który jest dostępny dla podjęcia decyzji o strategicznym posunięciu, zarówno dla wyceny wartości projektu inwestycyjnego jak i wartości opcji – możliwości przesunięcia decyzji na późniejszy optymalny termin