Engineering Commons^™

Urban Versus Lake Impacts On Heat Stress And Its Disparities In A Shoreline City, T. C. Chakraborty, Jiali Wang, Yun Qian, William Pringle, Zhao Yang, Pengfei Xue

Michigan Tech Publications, Part 2

Shoreline cities are influenced by both urban-scale processes and land-water interactions, with consequences on heat exposure and its disparities. Heat exposure studies over these cities have focused on air and skin temperature, even though moisture advection from water bodies can also modulate heat stress. Here, using an ensemble of model simulations covering Chicago, we find that Lake Michigan strongly reduces heat exposure (2.75°C reduction in maximum average air temperature in Chicago) and heat stress (maximum average wet bulb globe temperature reduced by 0.86°C) during the day, while urbanization enhances them at night (2.75 and 1.57°C increases in minimum average air …

University Of Kentucky Measurements Of Wind, Temperature, Pressure And Humidity In Support Of Lapse-Rate Using Multisite Fixed-Wing And Rotorcraft Unmanned Aerial Systems, Sean C. C. Bailey, Michael P. Sama, Caleb A. Canter, Luis Felipe Pampolini, Zachary S. Lippay, Travis J. Schuyler, Jonathan D. Hamilton, Sean B. Macphee, Isaac S. Rowe, Christopher D. Sanders, Virginia G. Smith, Christina N. Vezzi, Harrison M. Wight, Jesse B. Hoagg, Marcelo I. Guzman, Suzanne Weaver Smith

Mechanical Engineering Faculty Publications

In July 2018, unmanned aerial systems (UASs) were deployed to measure the properties of the lower atmosphere within the San Luis Valley, an elevated valley in Colorado, USA, as part of the Lower Atmospheric Profiling Studies at Elevation – a Remotely-piloted Aircraft Team Experiment (LAPSE-RATE). Measurement objectives included detailing boundary layer transition, canyon cold-air drainage and convection initiation within the valley. Details of the contribution to LAPSE-RATE made by the University of Kentucky are provided here, which include measurements by seven different fixed-wing and rotorcraft UASs totaling over 178 flights with validated data. The data from these coordinated UAS flights …

Residential Attic Performance Comparison Research, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

This research project evaluated cooling energy and moisture-related impacts between conventional attic venting and sealed attic vents in a lab home located in central Florida. All tests had R30 insulation on the ceiling and the roof deck uninsulated. A total of four different test configurations were tested. The four tested configurations were: Attic Vented with Attic Ducts, Attic Vents Sealed with Attic Ducts, Attic Vented with Indoor Ducts, and Attic Vents Sealed with Indoor Ducts. On average the impact from sealing attic vents will increase annual cooling energy use in a Florida home between 5%-10%. For a 1620 square foot …

Piezoresponse, Mechanical, And Electrical Characteristics Of Synthetic Spider Silk Nanofibers, Nader Shehata, Ishac Kandas, Ibrahim Hassounah, Patrik Sobolčiak, Igor Krupa, Miroslav Mrlik, Anton Popelka, Jesse Steadman, Randolph V. Lewis

Biology Faculty Publications

This work presents electrospun nanofibers from synthetic spider silk protein, and their application as both a mechanical vibration and humidity sensor. Spider silk solution was synthesized from minor ampullate silk protein (MaSp) and then electrospun into nanofibers with a mean diameter of less than 100 nm. Then, mechanical vibrations were detected through piezoelectric characteristics analysis using a piezo force microscope and a dynamic mechanical analyzer with a voltage probe. The piezoelectric coefficient (d₃₃) was determined to be 3.62 pC/N. During humidity sensing, both mechanical and electric resistance properties of spider silk nanofibers were evaluated at varying high-level …

A Humidity-Controlled Fast Integrated Mobility Spectrometer (Hfims) For Rapid Measurements Of Particle Hygroscopic Growth, Tamara Pinterich, Steven R. Spielman, Yang Wang, Susanne V. Hering, Jian Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

We present a humidity-controlled fast integrated mobility spectrometer (HFIMS) for rapid particle hygroscopicity measurements. The HFIMS consists of a differential mobility analyzer (DMA), a relative humidity (RH) control unit and a water-based FIMS (WFIMS) coupled in series. The WFIMS (Pinterich et al., 2017) combines the fast integrated mobility spectrometer (Kulkarni and Wang, 2006a, b) with laminar flow water condensation methodologies (Hering and Stolzenburg, 2005; Spielman et al., 2017). Inside the WFIMS, particles of different electrical mobilities are spatially separated in an electric field, condensationally enlarged and imaged to provide 1 Hz measurements of size distribution spanning a factor of ∼3 …

Enhancing The Thermal Performance Of Temporary Fabric Structures For The Advanced Energy Efficient Shelter System, Justin E. Eshleman, Robert A. Lake, Ronald A. Coutu Jr.

Electrical and Computer Engineering Faculty Research and Publications

The focus of this research is to characterize the thermal load on temporary fabric shelters deployed in the Middle East in order to establish realistic contract specification for the thermal performance of future shelters. Three different testing methods were utilized to evaluate shelter thermal performance. Small-scale tests allowed for economical comparisons of different shelter materials and configurations.

Humidity Sensor Based On A Single-Mode Hetero-Core Fiber Structure, Qiang Wu, Yuliya Semenova, Jinesh Mathew, Pengfei Wang, Gerald Farrell

Articles

Using a small-core single-mode fiber (SCSMF), a novel relative humidity (RH) sensor based on an SMF28-SCSMFSMF28 fiber structure was proposed in this paper. By depositing a humidity sensitive material, such as poly (ethylene oxide) (PEO) on the bare SCSMF fiber, the proposed structure can act as an RH sensor with high sensitivity. Experiments demonstrated that the proposed RH sensor with PEO coating can achieve a sensitivity of 430nm per relative humidity unit (RHU) in the RH range from 80% to 83% RH and a sensitivity of 50nm per RHU in the RH range from 83% to 95% RH.

Building America Industrialized Housing Partnership (Baihp Ii), Annual Report - Budget Period 4 (Bp4), January 01, 2009 - December 31, 2009, Florida Solar Energy Center, Robert Abernethy

FSEC Energy Research Center®

This annual report summarizes the work conducted by the Building America Industrialized Housing Partnership (BAIHP - www.baihp.org) during the fourth budget period (BP4) of our contract, January 1, 2009 to December 31, 2009. Progress from the three previous budget periods is included for context.

BAIHP is led by the Florida Solar Energy Center (FSEC) of the University of Central Florida. With over 50 Industry Partners including factory and site builders, work was performed in four task areas:

• Task 1: System Evaluations
• Task 2: Prototype House Evaluations
• Task 3: Community Scale Evaluations
• Task 4: Post- Phase 3 Activities.

In Task 1, …

Top 10 Checklist - Energy-Efficient Buildings For The Southern United States, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

The following Top Ten Checklist provides recommendations for creating energy efficient commercial buildings in areas with hot and humid summers. Commercial and institutional buildings vary greatly, from one to another, in size, use, and type of construction. For purposes of this Top Ten Checklist we are assuming a medium-sized (20,000 to 50,000 ft²) office building located in areas with hot and humid summers. The issues that are raised here may equally apply to schools, churches, theaters, and some retail buildings.

Ac System Equipment Specification, Installation And Operational Options For Improved Indoor Humidity Control, Florida Solar Energy Center, Don B. Shirey Iii

FSEC Energy Research Center®

High-efficiency home designs have significantly reduced sensible cooling loads, and some building codes and IAQ standards have begun requiring continuous outdoor ventilation air. These trends have led to an increased prevalence of high indoor humidity conditions (Rudd and Henderson 2007). This paper presents a summary of low-cost or no-cost equipment selection and operation options for conventional residential air-conditioning equipment than can result in lower indoor humidity levels. These options should be evaluated and employed to the extent possible prior to considering the added first cost and operating costs of separate dehumidification equipment.

Case Study Of An Innovative Hvac System With Integral Dehumidifier, Florida Solar Energy Center, Richard Raustad

FSEC Energy Research Center®

In most applications, heating, ventilating, and air conditioning (HVAC) equipment is controlled to maintain an indoor dry-bulb set point temperature. Moisture removal by the HVAC system is considered to be an operational byproduct. During summer months, the operation of the HVAC system is usually sufficient to meet both the sensible and latent cooling loads. However, during other times of the year when sensible loads are reduced, the moisture load can be significantly higher than the available moisture removal capacity of the air conditioning system. This can lead to elevated indoor relative humidity levels and an uncomfortable indoor environment. In many …

Assessment Of The Effectiveness And Energy Efficiency Of Humidity Control Approaches In Vacant Florida Homes, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

In a hot and humid climate such as Florida, 'snowbirds' that leave their homes for extended summer periods need guidance on effective and energy efficient methods of humidity control. Experiments were performed in seven residences to evaluate various approaches to humidity control, including providing no mechanical system control. A humidity target was identified to maintain indoor relative humidity (RH) at 65% or lower most of the time. Providing no mechanical conditioning (letting the building 'float') yields relative humidity at 65% or below during hot and sunny weather in some homes, but not during cloudy weather. Setting the AC system thermostat …

Ac System Equipment Specification, Installation And Operational Issues That Can Enhance Indoor Humidity Control, Florida Solar Energy Center, Don B. Shirey Iii

FSEC Energy Research Center®

This report presents summary of research on equipment selection and operation issues with conventional air conditioning equipment that can be employed prior to seeking the added first cost and operating cost of separate dehumidifiers.

Hydrogen Peroxide Formation Rates In A Pemfc Anode And Cathode: Effect Of Humidity And Temperature, Vijay A. Sethuraman, John W. Weidner, Andrew T. Haug, Sathya Motupally, Lesia V. Protsailo

Faculty Publications

Hydrogen peroxide (H₂O₂) formation rates in a proton exchange membrane fuel cell (PEMFC) anode and cathode were estimated as a function of humidity and temperature by studying the oxygen reduction reaction (ORR) on a rotating ring disk electrode. Fuel cell conditions were replicated by depositing a film of Pt/Vulcan XC-72 catalyst onto the disk and by varying the temperature, dissolved O₂ concentration, and the acidity levels in hydrochloric acid (HClO₄). The HClO₄ acidity was correlated to ionomer water activity and hence fuel cell humidity. The H₂O₂ formation rates showed …

Closing The Gap: Getting Full Performance From Residential Central Air Conditioners. Task 4.2-Develop New Climate-Sensitive Air Conditioner, Design, Construction, And Testing., Florida Solar Energy Center, Don B. Shirey Iii

FSEC Energy Research Center®

This study evaluated the performance of a prototype air conditioning system. The configuration of the prototype was based on detailed simulation results performed as part of this study. The results of the previously completed simulation indicated that energy-efficient, properly-ventilated homes in humid climates need equipment options or configurations that can provide a modest amount of additional dehumidification capacity while coordinating their operation with conventional cooling and ventilation systems. A prototype air conditioning system was constructed using currently available components and provides a method to independently control sensible (temperature) and latent (moisture) building loads. The prototype system was tested in both …

Closing The Gap: Getting Full Performance From Residential Central Air Conditioners, Task 4 - Develop New Climate-Sensitive Air Conditioner, Simulation Results And Cost Benefit Analysis, Florida Solar Energy Center, Hugh Henderson, Jr.

FSEC Energy Research Center®

This study evaluated the impacts of conventional and advanced cooling and dehumidification equipment on residential indoor humidity levels and annual energy consumption using whole building computer simulations. The life-cycle cost premium for the various advanced systems was also estimated. Building models were developed for a standard HERS Reference house, meant to represent current residential construction practice, and a High-Efficiency house that would likely qualify for a federal tax credit. The different houses were simulated in seven southeastern U.S. cities and with two ventilation/infiltration scenarios: 1) variable or natural infiltration alone, and 2) mechanical ventilation that complied with ASHRAE Standard 62.2-2004. …

An Autonomous And Adaptable Wireless Device For Flood Monitoring, Valerio Plessi, Filippo Bastianini, Sahra Sedigh

Electrical and Computer Engineering Faculty Research & Creative Works

Wireless devices can be used to monitor and record a broad range of phenomena. Their advantages include ease of installation and maintenance and considerable reduction in wiring costs. The addition of battery power and radio communication to such wireless devices can result in a completely The operating environment of monitoring systems is often hostile, due to temperature fluctuations, humidity, electromagnetic noise, and other interfering phenomena. The system should be able to adapt to changing conditions to maintain dependability in its operations This paper presents the case study of adapting a flood detection device to the environmental threat of submersion.

Abstract/Conclusion: Understanding The Dehumidification Performance Of Air-Conditioning Equipment At Part-Load Conditions, Florida Solar Energy Center, Don B. Shirey Iii

FSEC Energy Research Center®

Air conditioner cooling coils typically provide both sensible cooling and moisture removal. Data from a limited number of field studies (Khattar et al. 1985; Henderson and Rengarajan 1996; Henderson 1998) have demonstrated that the moisture removal capacity of a cooling coil degrades at part-load conditions, especially when the supply fan operates continuously while the cooling coil cycles on and off. Degradation occurs because moisture that condenses on the coil surfaces during the cooling cycle evaporates back into air stream when the coil is off. This degradation affects the ability of cooling equipment to maintain proper indoor humidity levels and may …

Understanding The Dehumidification Performance Of Air-Conditioning Equipment At Part-Load Conditions, Florida Solar Energy Center, Don B. Shirey Iii

FSEC Energy Research Center®

Air conditioner cooling coils typically provide both sensible cooling and moisture removal. Data from a limited number of field studies (Khattar et al. 1985; Henderson and Rengarajan 1996; Henderson 1998) have demonstrated that the moisture removal capacity of a cooling coil degrades at part-load conditions - especially when the supply fan operates continuously while the cooling coil cycles on and off. Degradation occurs because moisture that condenses on the coil surfaces during the cooling cycle evaporates back into air stream when the coil is off. This degradation affects the ability of cooling equipment to maintain proper indoor humidity levels and …

Cooling Load Reduction And Air Conditioner Design In A 19th Century Florida House Museum, Florida Solar Energy Center, David Chasar

FSEC Energy Research Center®

Restoration plans at the H.S. Williams house included the installation of a space conditioning system. This contract report details how building envelope construction and air conditioner design were optimized as a system. Many aspects of the effort lent themselves to maintaining important "character-defining" features of the building including the resurrection of passive cooling attributes like light colored exterior paint and operable storm shutters. In addition, outside air infiltration was measured on the Williams house and six other balloon-frame homes to document this often significant cooling load component.

Improving Doe-2'S Resys Routine: User Defined Functions To Provide More Accurate Part Load Energy Use And Humidity Predictions, Florida Solar Energy Center, Hugh Henderson, Jr.

FSEC Energy Research Center®

In hourly energy simulations, it is important to properly predict the performance of air conditioning systems over a range of full and part load operating conditions. An important component of these calculations is to properly consider the performance of the cycling air conditioner and how it interacts with the building. This paper presents improved approaches to properly account for the part load performance of residential and light commercial air conditioning systems in DOE-2. First, more accurate correlations are given to predict the degradation of system efficiency at part load conditions. In addition, a user-defined function for RESYS is developed that …

Comparative Summer Attic Thermal Performance Of Six Roof Constructions, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Florida Solar Energy Center (FSEC) has measured summer attic thermal performance of six roofs at a heavily instrumented test site, the Flexible Roof Facility (FRF). The FRF is a 1,152 square foot (107 m2) building with six roof adjacent test cells which are heavily insulated from each other. Some 233 channels of data were obtained; this includes twenty temperature measurements per cell, extensive meteorological conditions, surface and tower wind speeds and attic humidity and roof surface moisture accumulation. The data were collected over the ASHRAE definition of summer (June - September) to compare cooling season thermal of roofing systems. Six …

Ventilation, Humidity, And Energy Impacts Of Uncontrolled Airflow In A Light Commercial Building, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

A small commercial building was monitored before and after energy saving retrofits to study the impact of retrofits upon ventilation rates, humidity, building pressure and air conditioning energy use. Duct airtightness testing identified severe duct leakage as a significant source of uncontrolled airflow. Differential pressure and infiltration measurements using tracer gas indicated an attic exhaust fan as another significant source of uncontrolled airflow. Duct repair resulted in a 31% drop (30.5 kWh/day) in cooling energy, and an increase in relative humidity from 72% to 76%. Turning off the attic exhaust resulted in an additional 36% energy savings (14.3 kWh/day), including …

Field Measurement Of Uncontrolled Air Flow And Depressurization In Restaurants, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

Field investigations were done in seven restaurants (subsample of a 63 commercial buildings study) to identify uncontrolled air flows and pressure imbalances. Testing included building airtightness tests, identification of building air barrier location, duct system airtightness, characterization of pressure differentials, building air flow balance, and infiltration/ventilation rates. All restaurants were found to operate at negative pressures which ranged from -0.003 inWC (-0.8 Pa) to -0.173 inWC (-43 Pa) and averaged -0.051 inWC (-12.7 Pa) under normal operation. The variables which affect depressurization are large exhaust fans, missing or undersized make-up air, intermittent outdoor air caused by the cycling of air …

A Water And Heat Management Model For Proton-Exchange-Membrane Fuel Cells, Trung V. Nguyen, Ralph E. White

Faculty Publications

Proper water and heat management are essential for obtaining high-power-density performance at high energy efficiency for proton-exchange-membrane fuel cells. A water and heat management model was developed and used to investigate the effectiveness of various humidification designs. The model accounts for water transport across the membrane by electro-osmosis and diffusion, heat transfer from the solid phase to the gas phase and latent heat associated with water evaporation and condensation in the flow channels. Results from the model showed that at high current densities (> 1 A/cm²) ohmic loss in the membrane accounts for a large fraction of the …

Dealing With Heat & Humidity In Florida Homes, Florida Solar Energy Center, Robin Vieira

FSEC Energy Research Center®

Energy conservation is the solution to the problem of high electric bills. Much is known about home heating conservation, but conservation measures for cooling are not as well-known or widely practiced. This energy note focuses on heat and humidity sources that cause Floridians to run their air conditioners. It also presents conservation techniques that will reduce those air-conditioning requirements.

Temperature And Humidity Prediction In A Burley Curing Facility, Thomas C. Bridges, Linus R. Walton, Larry G. Wells, I. J. Ross

Biosystems and Agricultural Engineering Faculty Publications

No abstract provided.

Limiting Swine Stress With Evaporative Cooling In Kentucky, Robert L. Fehr, K. T. Priddy, Samuel G. Mcneill, Douglas G. Overhults

Agricultural Engineering Extension Updates

During the summer, temperatures in swine buildings often rise to levels that adversely affect animal performance and the profitability of these operations. Heat stress reduces reproductive efficiency in the breeding herd, affecting both the boar and sow. During extended hot weather periods, death of farrowing sows may result.

Estimation Of Pan Evaporation From Climatological Data, Jerald Emmet Christiansen, Ashwin D. Mehta

Reports

A new formula and coefficients for climatological factors was developed for estimating pan evaporation based on an analysis of data from 23 states in the U. S. and from five other countries. This formula may be written: Ev=K R Ct Cw Ch Cs Ce Cm in which K is a dimensionless constant R is the theoretical radiation reaching the outer atmosphere, expressed as equivalent evaporation in the same units~ , as Ev. Ct, Cw, Ch,and Cs are dimensionless sub-coefficients for temperature , wind, humidity, and sunshine. Ce is a sub-coefficient for elevation, and Cm is a monthly coefficient Equations were …