Engineering Commons^™

Measured Cooling Energy Savings From Reflective Wall Finishes: Evaluation As An Efficiency Measure Across Climates, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

In past research, reflective roofs have shown significant potential to reduce cooling in buildings. However, there have been few empirical evaluations of cooling reductions from changing wall reflectance. In the reported study, several experiments with instrumented scale test buildings are used to provide validation for a detailed simulation analysis across varied North American climates. The simulations establish the potential of reflective walls as an efficiency measure in existing buildings against climate.

This paper was published in the 2020 ACEEE Summer Study on Energy Efficiency in Buildings.

Field And Laboratory Testing Of Approaches To Smart Whole-House Mechanical Ventilation Control, Florida Solar Energy Center, Eric Martin

FSEC Energy Research Center®

Whole-house mechanical ventilation is a critical component to a comprehensive strategy for good indoor air quality (IAQ). However, due to lack of integration with standard heating and cooling systems, and perceptions from a portion of the homebuilding industry about risks related to increased energy use, increased cost, and decreased comfort, voluntary and code-required adoption varies amongst regions. Smart ventilation controls (SVC) balance energy consumption, comfort, and IAQ by optimizing mechanical ventilation operation to reduce the heating and/or cooling loads, improve management of indoor moisture, and maintain IAQ equivalence according to ASHRAE 62.2.Suggested Citation:Martin, E.; Fernaughty, K.; Parker, D.; Lubliner, M.; …

Design Of An Very High Efficiency Evaporatively Cooled Mini-Split Air Conditioner, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

An in-house research project at the Florida Solar Energy Center in 2013 was conducted to evaluate the potential of an evaporatively cooled mini-split heat pump. The mini-split heat pump modified was a 1.5-ton Fujitsu model with 19.2 SEER and 10.0 HSPF energy efficiency ratings. Cooling capacity of the system is variable and ranges from 7,000 to 23,000 Btu/h.

We demonstrated that it is possible to improve the energy efficiency of the evaluated mini-split air conditioner by 21% seasonally in Florida's humid climate using an evaporative pre-cooler. Further, we showed the same apparatus was able to improve air conditioner efficiency by …

Flexible Residential Test Facility: Impact Of Infiltration And Ventilation On Measured Cooling Season Energy And Moisture Levels (2016), Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Originally published in January 2014, this revision of the report clarifies and corrects references to Standard 62.2 as the 2013 version (62.2-2013), and it corrects the total CFM requirement for the subject buildings under the standard. Further, two plots have been updated to distinguish between the mechanical CFM and the total CFM required for the subject buildings under Standard 62.2-2013.

Evaluation Of The Impact Of Slab Foundation Heat Transfer On Heating And Cooling In Florida, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

The U.S. Department of Energy's Building America Partnership for Improved Residential Construction (BA-PIRC) performed experiments in the Florida Solar Energy Center's Flexible Residential Test Facility intended to assess for the first time (1) how slab-on-grade construction influences interior cooling in a cooling-dominated climate and (2) how the difference in a carpeted versus uncarpeted building might influence heating and cooling energy use.

Final Report: Cooling Seasonal Energy And Peak Demand Impacts Of Improved Duct Insulation On Fixed-Capacity (Seer 13) And Variable-Capacity (Seer 22) Heat Pumps, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

Previous phase 1, 2, and 3 research identified that duct conductive losses to an attic environment imposed greater relative energy losses for the variable-capacity systems compared to the fixed-capacity systems (Cummings and Withers 2011) because of the longer dwell time of conditioned air in the ducts. The purpose of the Phase 4 experiments reported here was to see if duct R-value enhancement would benefit the overall operating efficiency of the variable-capacity system relatively more than the fixed-capacity system. The current Phase 4 experiments (the primary focus of this report) found that this was a secondary effect.

Cooling And Heating Season Impacts Of Right-Sizing Of Fixed- And Variable-Capacity Heat Pumps With Attic And Indoor Ductwork, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

The U.S. Department of Energy's research team Building America Partnership for Advanced Residential Construction implemented two phases of experiments to examine the cooling and heating seasonal and peak demand performance of a variable-capacity 2-ton SEER 22 heat pump versus a 3-ton variable-capacity SEER 21 heat pump with attic ducts and indoor ducts. The experiments also compared the cooling and heating seasonal and peak demand performance of 2-ton versus 3-ton fixed-capacity SEER 13 heat pumps with attic ducts and indoor ducts.

Assessment Of Energy Efficient Methods Of Indoor Humidity Control For Florida Building Commission Research, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

This research project was conducted with the primary objective to identify approaches and technologies which can achieve energy-efficient latent cooling in light of code requirements that may increase overall ventilation rates in new Florida homes. This report covers the work of two primary efforts of completing a literature review and testing a few space conditioning methods in a mechanically ventilated building. Results from a literature review provide a list of various approaches to managing the latent load in homes with emphasis on energy efficiency and cost-effectiveness. In addition to a literature review, controlled experiments using four different approaches to space …

Flexible Residential Test Facility: Impact Of Infiltration And Ventilation On Measured Cooling Season Energy And Moisture Levels, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Air infiltration and ventilation in residential buildings is a very large part of the heating loads, but empirical data regarding the impact on space cooling has been lacking. Moreover, there has been little data on how building tightness might relate to building interior moisture levels in homes in a hot and humid climate. To address this need, BA-PIRC has conducted research to assess the moisture and cooling load impacts of airtightness and mechanical ventilation in two identical laboratory homes in the hot-humid climate over the cooling season.

Energy And Peak Power Reduction From Air Misting Products Applied To Commercial Condensing Units In Hot And Humid Climates, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

A proprietary research project was conducted to evaluate the potential annual and peak energy reduction resulting from the addition of a water misting system applied to supermarket condenser coils in the Florida Power and Light service territory. Tests were performed to evaluate the performance of a mist system under various outdoor conditions over an eight-month period in a hot and humid climate zone. The project measured an average of 2.8% percentage energy savings and average 3.2% utility peak demand reduction. The report discusses why hot and humid climates can expect much lower savings compared to hot and arid climates. One …

Determining Appropriate Heating And Cooling Thermostat Set Points For Building Energy Simulations For Residential Buildings In North America, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Existing building energy simulation tools have a purported tendency to over-predict heating use and, in some cases, to under-predict cooling use, an outcome often attributed to inappropriate assumptions about thermostat management. As a result, a systematic review was conducted for the purposes of determining typical heating and cooling set points for single-family houses in North America. The preliminary consensus results provide an empirical basis for establishing typical inputs for building energy simulation models, increasing prediction accuracy of heating and cooling loads. The results of this review have been applied as default values in the Lawrence Berkeley National Laboratory's Home Energy …

Measured Cooling Performance And Potential For Buried Duct Condensation In A 1991 Central Florida Retrofit Home, Florida Solar Energy Center, David Chasar

FSEC Energy Research Center®

The Florida Solar Energy Center (FSEC) conducted energy performance monitoring of two existing residences in Central Florida that were undergoing various retrofits. These homes were occupied by FSEC researchers and were fully instrumented to yield detailed energy, temperature, and humidity measurements. The data gave feedback about the performance of two levels of retrofit in two types of homes in a hot-humid climate. This report covers a moderate-level retrofit and includes 2 years of pre-retrofit data to characterize the impact of improvements. The other home, covered in a separate report (Parker and Sherwin 2012), is a deep energy retrofit that has …

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.

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.

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. …

Cooling Performance Assessment Of Building America Homes, Florida Solar Energy Center, David Chasar

FSEC Energy Research Center®

Long-term monitoring of building energy use and environmental conditions has been a strong component of FSEC research since the 1980s. Fully-automated data collection, verification, archiving and management ensure accurate logging of large amounts of data simultaneously from numerous field sites prior to being made available for analysis and display via the internet. Homes are typically monitored using 15 to 50 channels of data to measure indoor and outdoor environmental conditions and energy use of heating, cooling, water heating, whole house, and other points (e.g. Solar PV or Solar DHW) if needed.

Energy performance in many Building America homes has been …

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 …

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 …

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.

Fsec Approved Solar Energy Systems: Domestic Hot Water And Pool Heating, Florida Solar Energy Center, John Harrison

FSEC Energy Research Center®

This listing contains Florida Energy Factors for solar domestic hot water systems that have been approved by the Florida Solar Energy Center (FSEC) for use in the State. These energy factors represent the dimensionless ratio of the hot water energy made available by each approved system divided by the electrical energy used by the system. The Florida Energy Factor (FEF) is used to determine hot water credit multipliers for residential solar water heating systems in the 1993 Florida Energy Efficiency Code for Building Construction. The FEF can also be used to compare the efficiency of solar water heating systems with …

Field Testing And Computer Modeling To Characterize The Energy Impacts Of Air Handler Leakage, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

In order to determine the impact of air handler location upon heating and cooling energy use, the amount of air leakage which occurs in the air handler cabinet needs to be known. Also, the leakage which occurs at the connections between the air handler cabinet and the return and supply plenums needs to be known as well because these connection leaks would also be located in the attic or any other location.

In order to assess this leakage, testing was performed on a total of 69 air conditioning systems. Thirty systems were tested in the year 2001 under funding from …

Measured And Simulated Cooling Performance Comparison; Insulated Concrete Form Versus Frame Construction, Florida Solar Energy Center, David Chasar

FSEC Energy Research Center®

Four occupied homes near Dallas, Texas were monitored to compare cooling energy use. Two homes were built with typical wood frame construction, the other two with insulated concrete form (ICF) construction. Remote data loggers collected hourly readings of indoor and outdoor temperature, relative humidity, furnace runtime fraction, total building electrical energy and HVAC energy use. Data was recorded from January through August 2000.

Analysis of the measured data shows that insulated concrete form (ICF) construction can reduce seasonal cooling energy use 17 - 19% over frame construction in two-story homes in the North Texas climate. This result includes adjustments to …

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 …

Measured Impact Of Advanced Windows On Cooling Energy Use, Florida Solar Energy Center, Michael Anello

FSEC Energy Research Center®

A significant portion of Florida's residential building stock consists of single-family homes with clear, single-pane, aluminum frame windows. Such windows can lead to considerable heat gain during the hot Florida summer. A side-by-side field test in two identical homes was conducted to evaluate the impact of high performance windows on space cooling demand under realistic conditions.

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 …

How Contractors Really Size Air Conditioning Systems, Florida Solar Energy Center, Robin Vieira

FSEC Energy Research Center®

This paper presents results from 489 of the 5559 Florida air conditioning contractors surveyed (an 8.5% response rate) regarding equipment sizing methods in new residences. Air conditioning sizing is accomplished by using ACCA's Manual-J procedure by 33% of the respondents, software by 34.4% of the respondents, square-footage by 24.2% and other estimate procedures by about 8.4%. Those using square-footage estimates varied from 350 square-feet- per-ton to 700 square-feet-per-ton. Over a third of respondents indicated oversizing intentionally on some jobs, in order to avoid complaints, accommodate future expansions, enable quicker cooling down of homes, and to allow for lower cooling set …

Are Energy Savings Due To Ceiling Fans Just Hot Air?, Florida Solar Energy Center, Patrick James

FSEC Energy Research Center®

Human comfort studies have shown that people prefer higher temperatures when they are subjected to a breeze. Ceiling fans are often used to create air motion in residences. Simulation studies (including one given in this paper) have demonstrated that in Florida, using ceiling fans combined with raising a home's temperature 2° F will generate about a 14% net savings in annual cooling energy use (subtracting out the ceiling fan energy and accounting for internally released heat). This savings drops to 2.6% with a 1° F increase in set point and to a negative 3.7% savings with only a 0.5° F …

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 …