Experimental simulation of wind driven cross-ventilation in a naturally ventilated building

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.Includes bibliographical references (p. 29).A device was designed and constructed to simulate cross-ventilation through a building due to natural wind. The wind driver device was designed for use with a one tenth scale model of an open floor plan office building in Luton, England. The air flow patterns produced by the wind driver were observed, and the uniformity of the velocity of the flows into the model windows was measured for the three settings of the wind driver fans. The temperatures and velocities of flows on the interior of the building and at the exhaust windows were also examined. The wind driver device was capable of producing uniform velocities across the face of the model to within 20 to 27%, depending on the fan setting. The consistency of certain features of the velocity distributions produced by the wind driver operating at different speeds suggest that improvements made to the design of the wind driver could lower this variation to about 15%. The velocities measured on the interior of the model seem consistent with interior velocities in the Luton building, although further experimentation is needed to confirm this trend. Cross-ventilation was effective in reducing interior model temperatures by up to 10⁰C from the natural convection case.by Erin L. Hult.S.B

Helping underserved leaders transition: a school based pre-vocational skills program

The transition from high school to adulthood is typically accompanied by student’s prepping and planning for post-secondary education and employment following the completion of their education. Obtaining employment is a key milestone in a young adult’s life and provides the opportunity for earning money, living independently, and actively participating within the community and work environment. Young adults with disabilities (YADs) face numerous barriers when attempting to prepare for and obtain employment. Barriers such as transportation, employer bias, and an individual's interpersonal factors contribute to poorer employment outcomes for YADs when compared to neurotypical same aged peers. Helping Underserved Leaders Transition (HULT) is a school based pre- vocational skills program developed to address poor employment outcomes for YADs. Utilizing a mixed methods research design, HULT derives both qualitative and quantitative data from each program stakeholder including the students, their families and/or caregivers, and the school district administrators assisting with the logistics of the program implementation. Using quantitative data measures such as the use of Likert scales, HULT analyzes several outcomes before and after program participation related to the students’ skills in areas such as level of self-esteem, level of independence while completing vocational tasks, and ability to utilize coping strategies. Pre-vocational training within a school setting provides a dynamic and unique addition to YADs educational experience. HULT in conjunction with community resources and school curriculum allows students to prepare for their future employment endeavors earlier and within an inclusive, client centered environment. HULT demonstrates the importance of pre-vocational skills programming earlier in a student’s education to ensure accessibility and to improve overall employability for YADs

Energy Management in Small Commercial Buildings: A Look at How HVAC Contractors Can Deliver Energy Efficiency to this Segment

While buildings smaller than 50,000 sq ft account for nearly half of the energy used in US commercial buildings, energy efficiency programs to-date have primarily focused on larger buildings. Interviews with stakeholders and a review of the literature indicate interest in energy efficiency from the small commercial building sector, provided solutions are simple and low-cost. An approach to deliver energy management to small commercial buildings via HVAC contractors and preliminary demonstration findings are presented. The energy management package (EMP) developed includes five technical elements: benchmarking and analysis of monthly energy use; analysis of interval electricity data (if available), a one-hour onsite walkthrough, communication with the building owner, and checking of results. This data-driven approach tracks performance and identifies low-cost opportunities, using guidelines and worksheets for each element to streamline the delivery process and minimize the formal training required. This energy management approach is unique from, but often complementary to conventional quality maintenance or retrofit-focused programs targeting the small commercial segment. Because HVAC contractors already serve these clients, the transaction cost to market and deliver energy management services can be reduced to the order of hundreds of dollars per year. This business model, outlined briefly in this report, enables the offering to benefit the contractor and client even at the modest expected energy savings in small buildings. Results from a small-scale pilot of this approach validated that the EMP could be delivered by contractors in 4-8 hours per building per year, and that energy savings of 3-5percent are feasible through this approach

Blower-door techniques for measuring interzonal leakage

AbstractThe standard blower door test methods, such as ASTM E779, describe how to use a single blower door to determine the total leakage of a single-zone structure such as a detached single-family home. There are no standard test methods for measuring interzonal leakage in a two-zone or multi-zone building envelope such as might be encountered in with an attached garage or in a multifamily building. Some practitioners have been using techniques that involve making multiple measurements with a single blower door as well as combined measurements using multiple blower doors. Even for just two zones there are dozens of combinations of one-door and two-door test protocols that could conceivably be used to determine the interzonal air tightness. We examined many of these two-zone configurations using both simulation and measured data to estimate the accuracy and precision of each technique for realistic measurement scenarios. We also considered the impact of taking measurements at a single pressure versus over multiple pressures. We compared the various techniques and evaluated them for specific uses. Some techniques work better in one leakage regime; some are more sensitive to wind and other noise; some are more suited to determining only a subset of the leakage values. This paper makes recommendations on which techniques to use or not use for various cases and provides data that could be used to develop future test methods

Unlocking Energy Efficiency in Small Commercial Buildings through Mechanical Contractors

Although buildings smaller than 4,645 m2 account for nearly half of the energy used in U.S. commercial buildings, energy-efficiency programs to date have primarily focused on larger buildings. Stakeholder interviews conducted during a scoping study by Lawrence Berkeley National Laboratory (LBNL) indicated interest in energy efficiency from the small commercial building sector, provided solutions are simple and of low cost. To address this need, an energy management package (EMP) was developed to deliver energy management to small commercial buildings via HVAC contractors, because they already serve these clients and the transaction cost to market would be reduced. This energy-management approach is unique from, but often complementary to, conventional quality maintenance or retrofit-focused programs targeting the small commercial segment. This paper presents an overview of the EMP, the business model to deliver it, and preliminary demonstration findings from a pilot use of the EMP. Results from the pilot validated that contractors could deliver the EMP in 4-8 h per building per year and that energy savings of 3-5% are feasible through this approach