Engineering Commons^™

Improving Energy Savings And Peak Demand Reduction Estimates Using Ami Data For Utility Commercial Rebate Programs, Florida Solar Energy Center, Karen Fenaughty

FSEC Energy Research Center®

Solar reflective, or cool roofs, are a demonstrated method of reducing air conditioning energy, particularly in cooling-dominated climates. Similarly, efficient lighting or mechanical equipment replacement programs have a reputation for achieving large savings in c01mnercial buildings. Savings estimates for such measures have historically used monthly utility bills, which only provide a macroscopic view of utility program savings. Advanced Metering Infrastructure (AMI) is commonly used in the U.S. by utilities for residential and commercial customers and provides not only a valuable record of changing premise energy use and demand profiles but in much greater detail than utility bills, if desired.

Partnering …

Simulating The Energy Performance Of A Foam Roof System, Florida Solar Energy Center, Jeffrey Sonne

FSEC Energy Research Center®

Annual residential simulations were run in 13 US cities to determine the energy savings of using an insulated foam tile roof in retrofit applications where ceiling insulation was only R-11 or R-19. Variations included leaving the attic vented and sealing the attic space.

Building America Industrialized Housing Partnership (Baihp Ii)Final Report Budget Periods 1-5, April 1, 2006 - November 30, 2010, Florida Solar Energy Center, Robert Abernethy

FSEC Energy Research Center®

This report summarizes the work conducted by the Building America Industrialized Housing Partnership (BAIHP - www.baihp.org) during the final budget period (BP5) of our contract, January 1, 2010 to November 30, 2010. Highlights from the four previous budget periods are 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 in BP5 was performed in six tasks areas:

• Task 1: Building America System Research Management, Documentation and Technical Support
• Task 2A: Stage G1A: Integrated Solutions for Specific Climate Regions
• Task …

Nightcool: Nocturnal Radiation Cooling Concept, Long Term Performance Evaluation, Florida Solar Energy Center, John Sherwin

FSEC Energy Research Center®

An experimental evaluation has been conducted on a building-integrated night sky cooling system designed to substantially reduce space cooling needs in homes in North American climates. The system uses a sealed attic covered by a highly conductive metal roof (a roof integrated radiator) which is selectively linked by air flow to the main zone with the attic zone to provide cooling - largely during nighttime hours. Available house mass is used to store sensible cooling. The system's capability for solar dehumidification with minimal electricity input is demonstrated with long-term performance data taken over 2007 - 2009. A year-long study period …

Energy Performance Aspects Of A Florida Green Roof, Part 2, Florida Solar Energy Center, Jeffrey Sonne

FSEC Energy Research Center®

This monitored study is an evaluation of summer and winter energy performance aspects of a green roof on a 2-story central Florida university building addition that was completed in 2005. An earlier report on this study was published through the 2006 Symposium on Improving Building Systems in Hot and Humid Climates. This report reviews these earlier results and provides second-summer results which show significant performance improvements for the green roof compared with the first summer results.

Nightcool: A Nocturnal Radiation Cooling Concept, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

An experimental evaluation has been conducted on a night sky cooling system designed to substantially reduce space cooling needs in homes in North American climates. The system uses a sealed attic covered by a highly conductive metal roof (a roof integrated radiator) which is selectively linked by air flow to the main zone with the attic zone to provide cooling - largely during nighttime hours. Available house mass is used to store sensible cooling. Currently, the system's capability for solar dehumidification with minimal electricity input is demonstrated.

Experimental Evaluation Of The Nightcool Nocturnal Radiation Cooling Concept: Annual Performance Assessment In Scale Test Buildings, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

An experimental evaluation has been conducted on a night sky cooling system designed to substantially reduce space cooling needs in homes in North American climates. The system uses a sealed attic covered by a highly conductive metal roof (a roof integrated radiator) which is selectively linked by air flow to the main zone with the attic zone to provide cooling--largely during nighttime hours. Available house mass is used to store sensible cooling. Additional dehumidification is done during the evening hours as warranted by interior conditions.

An initial report describes a detailed simulation model of the relevant night cooling phenomenon, examining …

Experimental Evaluation Of Nightcool Nocturnal Radiation Cooling Concept: Performance Assessment In Scale Test Buildings, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

An experimental test evaluation has been conducted of a night sky cooling system designed to substantially reduce space cooling needs in homes in North American climates. The system uses a sealed attic covered by a highly conductive metal roof (a roof integrated radiator) which is selectively linked by air flow to the main zone with the attic zone to provide cooling- largely during nighttime hours. Available house mass is used to store sensible cooling. Additional dehumidification is done during the evening hours as warranted by interior conditions.

A previous report describes a detailed simulation model of the relevant night cooling …

Energy Efficient Renovations Of Storm Damaged Residences - Florida Case Studies, Florida Solar Energy Center, Neil Moyer

FSEC Energy Research Center®

Storm-damaged homes offer the opportunity for repairs that reduce energy use, improve comfort and enhance resistance to future storms. Case studies of four Florida homes damaged in the summer of 2004 were documented to show the costs and benefits of various retrofit strategies. All four homes required roof replacement and each took advantage of roof cladding with higher reflectance than the original, a proven means of reducing cooling energy use. Two of the case studies included improvements to attic insulation, tightening of the envelope and/or duct system and improved efficiency equipment and lighting. Energy savings attributable to storm repairs were …

Energy Performance Aspects Of A Florida Green Roof, Florida Solar Energy Center, Jeffrey Sonne

FSEC Energy Research Center®

Previous green roof studies have found that planted roofs significantly reduce roof temperatures and roof heat flux, and simulations indicate cooling load reductions of up to 25%. This monitored study evaluates summer and winter energy performance aspects of a green roof on a central Florida university building addition that was completed in 2005.

Analysis of 2005 summer data indicates significantly lower peak roof surface temperatures for the green roof compared with the conventional roof and a significant shift in when the peak temperature occurs compared to the conventional roof. Summer roof heat flux estimates show the green roof to have …

Technical Support For Development Of An Attic Simulation Model For The California Energy Commission, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

The California Energy Commission (CEC) is developing a new attic simulation model for assessing residential energy performance within its Title 24 residential compliance methodology. Within this project, we are providing technical support to assist Bruce Wilcox and CEC in development of the model based on Florida Solar Energy Center (FSEC) experience with similar models. We assisted the effort by using data from FSEC instrumented facilities to help verify the eventual simulation. We also outlined critical issues for modeling with the development of the simulation. Given the importance of attic ventilation, we are also conducting new studies of varied ventilation rates …

Flexible Roofing Facility: 2004 Summer Test Results, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

The Flexible Roof Facility (FRF) is a test facility in Cocoa, Florida designed to evaluate five roofing systems at a time against a control roof with black shingles and vented attic (Figure E-1). Since 1989 the testing has evaluated how roofing systems impact summer residential cooling energy use and peak demand. In the summer of 2004, the following roofing systems were tested. Materials tested were: Galvalume® unfinished (unpainted) 5-vee metal with vented attic (3rd year of exposure), galvanized unfinished 5-vee metal with vented attic (3rd year of exposure, black shingles with standard attic ventilation (Control Test Cell), white standing seam …

Theoretical Evaluation Of The Nightcool Nocturnal Radiation Cooling Concept, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

An evaluation has been conducted of the potential of a night sky cooling system to substantially reduce space cooling needs in homes in North American climates. The report describes the innovative residential cooling system which uses nocturnal night sky radiation from a roof integrated radiator. The system uses a sealed attic covered by a highly conductive metal roof which is selectively linked by air flow to the main zone with the attic zone to provide cooling- largely during nighttime hours. Available house mass is used to store sensible cooling. Additional dehumidification is done during the evening hours as warranted by …

Geographic Variation In Potential Of Rooftop Residential Photovoltaic Electric Power Production In The United States, Florida Solar Energy Center, Matthew Lombardi

FSEC Energy Research Center®

This paper describes a geographic evaluation of Zero Energy Home (ZEH) potential, specifically an assessment of residential roof-top solar electric photovoltaic (PV) performance around the United States and how energy produced would match up with very-efficient and super-efficient home designs. We performed annual simulations for 236 TMY2 data locations throughout the United States on two highly-efficient one-story 3-bedroom homes with a generic grid-tied solar electric 2kW PV system. These annual simulations show how potential annual solar electric power generation (kWh) and potential energy savings from PV power vary geographically around the U.S. giving the user in a specific region an …

Flexible Roofing Facility: 2003 Summer Test Results, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

The Flexible Roof Facility (FRF) is a test facility in Cocoa, Florida designed to evaluate five roofing systems at a time against a control roof with black shingles and vented attic (Figure E-1). The testing evaluates how roofing systems impact summer residential cooling energy use and peak demand. In the summer of 2003, the following roofing systems were tested: Galvalume® unfinished 5-vee metal with vented attic (2nd year of exposure); sealed attic with proprietary configuration; high reflectance brown metal shingle with vented attic; galvanized unfinished 5-vee metal with vented attic (2nd year of exposure); black shingles with standard attic ventilation …

Flexible Roofing Facility: 2001 Summer Test Results, Florida Solar Energy Center, Jeffrey Sonne

FSEC Energy Research Center®

The Flexible Roof Facility (FRF) is a test facility in Cocoa, Florida designed to evaluate five roofing systems at a time against a control roof with dark shingles. The intent of the testing is to evaluate how roofing systems impact summer residential cooling energy use and peak demand. In the summer of 2001, the following roofing systems were tested.

Cell # Description

1. Weathered white barrel tile with sealed attic
2. Double roof with radiant barrier, sealed attic and insulated roof deck
3. High reflectance brown metal shingle with vented attic
4. Terra cotta barrel tile with vented attic
5. Dark shingles with standard attic …

Comparative Evaluation Of The Impact Of Roofing Systems On Residential Cooling Energy Demand In Florida, Florida Solar Energy Center, John Sherwin

FSEC Energy Research Center®

Roof and attic thermal performance exert a powerful influence on cooling energy use in Florida homes. The Florida Power and Light Company and the Florida Solar Energy Center instrumented six side-by-side Habitat homes in Ft. Myers, Florida with identical floor plans and orientation, R-19 ceiling insulation, but with different roofing systems designed to reduce attic heat gain. A seventh house had an unvented attic with insulation on the underside of the roof deck rather than the ceiling: (RGS) Standard dark shingles (control home); (RWB) White "Barrel" S-tile roof; (RWS) Light colored shingles; (RWF) White flat tile roof; (RTB) Terra cotta …

A Summary Report On The Application Of Photovoltaic Systems And Metal Roofs, Florida Solar Energy Center, Stephen Barkaszi

FSEC Energy Research Center®

A recent resurgence of interest in roof-mounted photovoltaic systems has prompted the Florida Solar Energy Center to assess the current state of the technology from a systems viewpoint. A major part of the system that is often underestimated in the performance and economics of the system is the roof structure. The type of roof can significantly affect both the initial cost of an installation and the life cycle costs.

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 …

Demonstration Of Cooling Savings Of Light Colored Roof Surfacing In Florida Commercial Buildings: Retail Strip Mall, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

A series of tests were conducted in seven retail shops in a strip mall in Cocoa, Florida to examine how roof whitening would impact air conditioning load. The roof of the strip mall was conventional: unsurfaced galvanized corrugated metal with R-11 insulation suspended by purlins underneath. Below the insulation was the roof plenum which contained both the air handler and duct air distribution system. Cooling was accomplished in each shop by a dedicated direct expansion air conditioning (AC) system between 3 and 4 tons in size. Each had its air conditioning metered for half of the summer in a baseline …

Demonstration Of Cooling Savings Of Light Colored Roof Surfacing In Florida Commercial Buildings: Our Savior's School, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Architects and designers have long known that light-colored building roofs can reduce cooling needs. Recently, monitoring studies in Florida have made an effort to quantify these savings. Experiments in existing residences have shown that a white reflective roof can reduce cooling requirements by an average of 20%. However, until now there has been no investigation in Florida's climate to examine the potential in commercial scale buildings.

To remedy this need, a two year study was performed on a private elementary school building in Cocoa Beach, Florida. Our Savior's Elementary School was monitored for an entire year in a base line …

Monitored Energy Use Patterns In Low-Income Housing In A Hot And Humid Climate, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

The Florida Solar Energy Center (FSEC) is metering energy use in two Habitat for Humanity developments. The objective is to understand how energy is used in low income housing and how it can be effectively reduced. The ten "control homes" come from a conventional housing project built by in 1993 Habitat for Humanity in Homestead, Florida. Another ten "experimental homes" have been recruited from the 190 home Jordan Commons development in the same vicinity. These houses, which are soon to be metered, are designed to be energy efficient with high SEER air conditioners, reflective roofing, solar water heaters and energy …

The Measured Summer Performance Of Tile Roof Systems And Attic Ventilation Strategies In Hot, Humid Climates, Florida Solar Energy Center, David Beal

FSEC Energy Research Center®

During 1994, simultaneous full-scale testing of residential plywood-decked roofing system was conducted using a flexible roof facility (FRF). The facility consists of a 24-ft by 48ft rectangular building with one large conditioned space under an attic that is partitioned into six separate test cells. Throughout the test protocol one cell was configured as a residential black-shingle roof system, employed as the baseline for comparison of the alternative roofing systems.

Two identical cells were employed during the summer of 1994 to investigate soffit and ridge venting. Tests of two different configurations best illustrate the results. A comparison of a sealed attic …

Measured Cooling Energy Savings From Reflective Roofing Systems In Florida: Field And Laboratory Research Results, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

A series of field experiments in Florida have examined the impact of reflective roof coatings on air conditioning energy use in occupied homes. The tests were conducted on nine residential buildings from 1991 to 1994 using a before and after protocol where the roofs were whitened at mid-summer. Measured AC electrical savings in the buildings during similar pre- and post-retrofit periods averaged 19%, ranging from a low of 2% to a high of 43%. Utility peak coincident peak savings averaged 22%. Cooling energy reductions appear to depend on ceiling insulation level and roof solar reflectance, air duct system location and …

Laboratory Testing Of The Reflectance Properties Of Roofing Materials, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Past simulation and test cell studies have shown potential reduction to building cooling loads from higher exterior surface solar reflectances (Givoni and Hoffman, 1968; Givoni, 1976; Chuan and Busching, 1983; Griggs and Shipp, 1988; Anderson, 1989; Akbari et al., 1990; Chandra and Moalla, 1991; Bansal et al., 1992). Furthermore, simulation analysis of macro-climatic effects have shown that light colored surfaces may reduce the magnitude of the urban heat island (Taha et al., 1988; Akbari et al, 1989; Akbari et al., 1992).

Figure 1 shows a graphic illustration of the potential influence of surface reflectance on roof solar heat gain. The …

Concepts In Passive Design #1 Roof Overhangs, Florida Solar Energy Center, Philip Fairey

FSEC Energy Research Center®

A major source of heat in buildings is direct solar radiation through windows--welcome in cold weather, but a problem in hot weather. Since Florida has such a lengthy cooling season, it is most important to protect windows from the sun; however, there are times between November and March when some heat is needed. Fortunately, the change in the sun's path from summer to winter is such that a properly designed roof overhang can protect south-facing windows from the high summer sun, yet allow the lower winter sun to come in.