Engineering Commons^™

Assessing Six Residential Ventilation Techniques In Hot And Humid Climates, Florida Solar Energy Center, Neil Moyer

FSEC Energy Research Center®

The addition of mechanical ventilation air to "tight" homes in hot and humid climates may adversely impact health, building durability, comfort and energy use by raising indoor humidity levels (RH) above 50%. High indoor humidity has been linked to microbial growth, building material decay, discomfort, and increased energy use (Moyer, et al, 2001). High indoor humidity in "tight" homes with mechanical ventilation has been documented in various Building America projects in hot humid locations (Rudd 2003).

The research described here quantifies the energy use, and humidity impacts of six mechanical ventilation strategies installed serially in a new, Energy Star Manufactured …

Standards For Clean Air Florida Homes, Florida Solar Energy Center, Subrato Chandra

FSEC Energy Research Center®

These standards are designed for new, slab on grade homes built in Florida. Changes to the standards may be necessary for other house construction types. These standards are not meant to be exclusionary. The home builder may submit alternative materials or design details which will result in equivalent performance. These standards complement all building codes and do not supersede any codes.

Performance And Impact From Duct Repair And Ventilation Modifications Of Two Newly Constructed Manufactured Houses Located In A Hot And Humid Climate, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

Two nearly identical houses situated next to each other in Bossier City, Louisiana were studied in an effort to better understand moisture and cooling energy related problems in manufactured houses with low thermostat set-points during the cooling season. By design, the major difference between houses was the type of air conditioning units. House A had a standard split air conditioner and House B had a two-speed split air conditioner.

In an effort to make the buildings more similar, the building airtightness was adjusted until it was the same in each house, and duct leaks were sealed so that the ducts …

Effects Of Ventilation On Human Thermal Comfort In Rooms, Ahmed F. Alfahaid

Mechanical & Aerospace Engineering Theses & Dissertations

Nowadays, the majority of people spend up to 90% of their time indoors; as a result, the maintenance of optimal indoor climate conditions has become important for their overall health and comfort. The main goal of this study is to predict numerically the flow and temperature patterns and the human thermal comfort conditions in an indoor environment using displacement ventilation.

A Computational Fluid Dynamics (CFD) code has been used to analyze thermal comfort conditions for a fullscale ventilated room. Unstructured grids have been used to discretize the numerical domain. Before undertaking a detailed investigation, the code was validated by comparing …

Evaluation Of Energy Efficient Improvements To Portable Classrooms In Florida, Florida Solar Energy Center, Michael Callahan

FSEC Energy Research Center®

Florida has over 25,000 portable classrooms in use around the state. Energy costs for these structures exceed $20 million a year - or about 11% of all energy-related expenditures for educational facilities. Research has also shown interior ventilation rates in these classrooms typically fall far below the recommended levels in ASHRAE Standard 62-1989.

To explore ways in which costs might be reduced and the physical learning environment improved, we conducted a two year experiment in two highly instrumented portable classrooms at Silver Sands Middle School in Volusia County. A series of retrofits, aimed to cut energy use and improve ventilation …

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 …

Monitored Summer Peak Attic Air Temperatures In Florida Residences, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Florida Solar Energy Center (FSEC) has analyzed measured summer attic air temperature data taken for some 21 houses (three with two different roof configurations) over the last several years. The analysis is in support of the calculation within ASHRAE Special Project 152P which will be used to estimate duct system conductance gains which are exposed to the attic space. Knowledge of prevailing attic thermal conditions are critical to the duct heat transfer calculations for estimation of impacts on residential cooling system sizing.

The field data was from a variety of residential monitoring projects which were classified according to intrinsic differences …

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 …

Controlling Ventilation And Space Depressurization Inrestaurants Inhot And Humid Climates, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

Testing was performed in 9 restaurants to identify uncontrolled air flows and pressure imbalances, building and duct system airtightness, building air barrier location, pressure differentials, building air flow balance, and ventilation rates. All restaurants are depressurized under normal operating conditions, ranging from -1.0 to -43 pascals. Space depressurization is a function of exhaust fan flow rates, missing or undersized make-up air, intermittent outdoor air caused by the cycling of air handlers, dirty outdoor air and make-up air filters, and building airtightness. Ventilation rates were found to be high, generally exceeding ASHRAE 62-1989 minimum recommended levels. Pressure imbalances and excessive ventilation …

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 …

Energy Efficient Office Building Design For A Hot And Humid Climate: Florida's New Energy Center, Florida Solar Energy Center, Philip Fairey

FSEC Energy Research Center®

Hot and humid climates, such as those in Florida, pose unique challenges to architects and engineers seeking energy efficient office building designs. The severe impact of internal loads on cooling, the intense solar conditions and the need for increased ventilation set against high relative humidities, all serve to limit the success of many conventional methods of reducing building energy use. To provide a high-visibility demonstration of potential energy design solutions, the Florida Solar Energy Center (FSEC) is building a state-of-the-art office complex for its new facility in Cocoa, Florida.

Measured Natural Cooling Enhancement Of A Whole House Fan, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

An experimental study was carried out in the summer of 1991 to investigate the natural cooling potential of use of a whole house fan in Central Florida's hot and humid climate. The residential building, in Cocoa Beach, FL, is typical of much of the existing housing stock in Florida: a concrete block structure with R-11 ceiling insulation. The building was ventilated with all windows open during the three month summer test period (June-August). Air temperatures and relative humidity inside the home interior along with exterior meteorological conditions (insolation, wind speed, air temperature, relative humidity) were scanned every five seconds with …

Thermal Performance Monitoring Results From The Residential Standards Demonstration Program, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

The Model Conservation Standards (MCS) were developed by the Northwest Power Planning Council in 1983. These standards were designed to save large amounts of space heating energy in new U.S. residential construction in the Pacific Northwest. Creation of the MCS resulted in a desire to demonstrate the actual savings of such energy efficiency standards. The Bonneville Power Administration sponsored the Residential Standards Demonstration Program (RSDP) in 1984 which resulted in the construction of 410 energy-efficient single-family homes in the four-state region. Typically these buildings incorporated design features such as high levels of insulation for attic, walls and floors, triple-glazed windows …

Procedures For Calculating Natural Ventilation Airflow Rates In Buildings. 03-87, Florida Solar Energy Center, Subrato Chandra

FSEC Energy Research Center®

This is the final report of ASHRAE research project 448-RP "Building Pressure Distribution for Natural Ventilation" initiated in October 1985. The objective of the research was to review the worldwide data on building pressure coefficient and to assimilate the data for use in hourly calculation of natural ventilation airflow rates in buildings. This report is organized in two parts. Part 1 is written for the user who wants to use the information. Part 2 provides the background and research data analysis which was conducted to come up with the Part 1 information.

Cooling With Ventilation, Florida Solar Energy Center, Subrato Chandra

FSEC Energy Research Center®

In keeping with the national energy policy foal of fostering an adequate supply of energy at a reasonable cost, the United States Department of Energy (DOE) supports a variety of programs to promote a balanced and mixed energy resource system. The mission of the DOE Solar Building Research and Development Program is to support this goal by providing for the development of solar technology alternatives for the buildings sector. It is the goal of the Program to establish a proven technology base to allow industry to develop solar products and designs for buildings that are economically competitive and can contribute …

Fitting The Mechanical Refrigerator Into The Home, E. B. Lewis, M. P. Brunig

Nebraska Agricultural Experiment Station: Historical Circulars

Within the last five years the mechanical refrigerator has become a popular piece of household equipment. Its year-round use has caused architects and others interested in planning for the convenience of the housewife to recommend placing the new cabinet in kitchens and other convenient places, with little thought about the effect on the operation of the refrigerator. The purpose of this publication is to point out some of the conditions under which the refrigerator has been expected to operate successfully, and some of the effects of these conditions upon the operation of the machine.