Improving the Energy Efficiency of Dehumidification Technology at a Large Facility in Florida


Book Description

This thesis examines energy use and management of twenty heat pipes used in dehumidification systems at a large (10,000+ acre) facility in Florida. Eleven of the twenty heat pipes use electric strip heaters that, when activated, consume 693.8 kW of electrical power from the grid. Solar photovoltaics, specifically a silicon monocrystalline cell with 22.5% efficiency, were considered as a means to provide an alternative energy source and opportunity for cost savings for 11 of the heat pipes (Sunpower, 2011). The remaining nine heat pipes use hot water heaters for which alternative energy sources were not considered. Data gathered and analyzed include weather, solar irradiance, PV size and cost, utility incentives, emissions, fuel consumption, energy cost, and heat pipe operating parameters. These data were used to calculate the (1) annual electricity cost for the heaters, (2) installed cost for enough PV to offset electric heater energy use, (3) surface area needed to install the estimated PV system, (4) one-time and ongoing financial incentives, (5) avoided energy savings, (6) avoided fuel usage and emissions, and (7) the undiscounted payback period of the various equipment investments. Savings were calculated to be almost 600,000 dollars annually (approximately 145,000 dollars attributable to the heaters) if PV were to power the heaters 125 days of the year and ancillary systems at other times. The cost of an appropriately sized PV system (4.57 acres with between 8,553 and 15,205 PV panels depending on panel size) was estimated at 3,228,806 dollars assuming 150,000 dollars of electric utility incentives. It was also estimated that the photovoltaic (PV) system could earn 85,087 dollars in annual tax credits through the Florida Renewable Energy Production Tax Credit program, and that the undiscounted payback period would be about five years. Further, the use of 728,350 US gallons of oil, and the emission of 13,656.6 lbs of SO2, 9,104.37 lbs of NOx, and 10,843,300 lbs of CO2, could also be avoided. It is recommended that the installation of PV energy generation capabilities be further investigated. It is also recommended that further research be performed to obtain accurate costs and benefits of integrating solar thermal into the hot water heaters at the facility because of the complexity of integrating solar thermal into the existing hot water heaters, the lack of readily available price information regarding solar thermal heating, and the fact that the hot water heaters consume about 170,000 dollars per year.










Florida Building Code - Energy Conservation, 7th Edition (2020)


Book Description

The 7th Edition (2020) update to the Florida Building Code: Energy Conservation is a fully integrated publication that updates the 6th Edition 2017 Florida Building Code: Energy Conservation using the latest changes to the 2018 International Energy Conservation Code® with customized amendments adopted statewide. Chapter tabs are also included. Effective Date: December 31, 2020




Improving Energy Efficiency in a Pharmaceutical Manufacturing Environment -- Production Facility


Book Description

The manufacturing plant of a pharmaceutical company in Singapore had low energy efficiency in both its office buildings and production facilities. Heating, Ventilation and Air-Conditioning (HVAC) system was identified to be the major energy consumer in the plant. An HVAC specific energy management tool was developed to monitor the energy efficiency and calculate the heat gains and cooling loads. In the office building, the HVAC operation schedule was revised, and motion detection lighting control was installed and configured to save electricity. In production facilities, house vacuum, process vacuum and dust collector were shut down during non-production time in Pharmaceutical Facility 2 (PF2). Statistical analysis using measured data was performed to verify the projected energy savings. Dehumidifier was disabled in Pharmaceutical Facility 1 (PF1) to relax the relative humidity from around 22% to 50%, while still maintaining it within the upper specification of 55%. Theoretical AHU-Dehumidifier models were built to find the optimum system settings with minimum energy consumption. With the implemented strategies, the annual energy consumption would be reduced by 6.68%, 6.58% and 2.32% in the office building, PF1 and PF2 respectively. The AHU-Dehumidifier models suggested a pre-cooling off-coil temperature of 15.50 C and a post-cooling off-coil temperature of 21 'C in face of the current humidity requirement to achieve minimum energy consumption.




Evaluation of Humidity Control Options in Hot-Humid Climate Homes (Fact Sheet).


Book Description

This technical highlight describes NREL research to analyze the indoor relative humidity in three home types in the hot-humid climate zone, and examine the impacts of various dehumidification equipment and controls. As the Building America program researches construction of homes that achieve greater source energy savings over typical mid-1990s construction, proper modeling of whole-house latent loads and operation of humidity control equipment has become a high priority. Long-term high relative humidity can cause health and durability problems in homes, particularly in a hot-humid climate. In this study, researchers at the National Renewable Energy Laboratory (NREL) used the latest EnergyPlus tool equipped with the moisture capacitance model to analyze the indoor relative humidity in three home types: a Building America high-performance home; a mid-1990s reference home; and a 2006 International Energy Conservation Code (IECC)-compliant home in hot-humid climate zones. They examined the impacts of various dehumidification equipment and controls on the high-performance home where the dehumidification equipment energy use can become a much larger portion of whole-house energy consumption. The research included a number of simulated cases: thermostat reset, A/C with energy recovery ventilator, heat exchanger assisted A/C, A/C with condenser reheat, A/C with desiccant wheel dehumidifier, A/C with DX dehumidifier, A/C with energy recovery ventilator, and DX dehumidifier. Space relative humidity, thermal comfort, and whole-house source energy consumption were compared for indoor relative humidity set points of 50%, 55%, and 60%. The study revealed why similar trends of high humidity were observed in all three homes regardless of energy efficiency, and why humidity problems are not necessarily unique in the high-performance home. Thermal comfort analysis indicated that occupants are unlikely to notice indoor humidity problems. The study confirmed that supplemental dehumidification is needed to maintain space relative humidity (RH) below 60% in a hot-humid climate home. Researchers also concluded that while all the active dehumidification options included in the study successfully controlled space relative humidity excursions, the increase in whole-house energy consumption was much more sensitive to the humidity set point than the chosen technology option. In the high-performance home, supplemental dehumidification equipment results in a significant source energy consumption penalty at 50% RH set point (12.6%-22.4%) compared to the consumption at 60% RH set point (1.5%-2.7%). At 50% and 55% RH set points, A/C with desiccant wheel dehumidifier and A/C with ERV and high-efficiency DX dehumidifier stand out as the two cases resulting in the smallest increase of source energy consumption. At an RH set point of 60%, all explicit dehumidification technologies result in similar insignificant increases in source energy consumption and thus are equally competitive.







Building America Case Study


Book Description

This report, Evaluation of the Performance of Houses with and without Supplemental Dehumidification in a Hot-Humid Climate, describes a research study that that was conducted by the Building Science Corporation (BSC) Building America Research Team. BSC seeks to research and report on the field monitoring of the performance of in-situ supplemental dehumidification systems in low energy, high performance, homes in a Hot-Humid climate. The purpose of this research project was to observe and compare the humidity control performance of new, single family, low energy, and high performance, homes. Specifically, the study sought to compare the interior conditions and mechanical systems operation between two distinct groups of houses, homes with a supplemental dehumidifier installed in addition to HVAC system, and homes without any supplemental dehumidification. The subjects of the study were ten single-family new construction homes in New Orleans, LA. Data logging equipment was installed at each home in 2012. Interior conditions and various end-use loads were monitored for one year. In terms of averages, the homes with dehumidifiers are limiting elevated levels of humidity in the living space. However, there was significant variation in humidity control between individual houses. An analysis of the equipment operation did not show a clear correlation between energy use and humidity levels. In general, no single explanatory variable appears to provide a consistent understanding of the humidity control in each house. Indoor humidity is likely due to all of the factors we have examined, and the specifics of how they are used by each occupant.







Testimony of members of Congress


Book Description