scholarly journals Photovoltaic Greenhouses: Comparison of Optical and Thermal Behaviour for Energy Savings

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Maurizio Carlini ◽  
Tommaso Honorati ◽  
Sonia Castellucci
Keyword(s):  
Food Production ◽  
Energy Savings ◽  
Climatic Parameters ◽  
Local Climate ◽  
Heating And Cooling ◽  
Productive Activities ◽  
Solar Greenhouse ◽  
Climate Exposure ◽  
Cultivated Plant ◽  
Computational Aspects

The production of energy from renewable sources, the diversification of the productive activities, and the development of photovoltaic technology and integrated systems have led to the development of solar greenhouses. The interest of the developers and designers is now to seek new approaches to combine the electricity and food production optimally. The interaction of factors as outside local climate, exposure, slope, soil, altitude, wind conditions, structural materials, or cultivated plant species, influences greatly the energy balance. This paper illustrates the comparison of optical and thermal behavior of a solar greenhouse and a similar glass greenhouse, devoted to the production of soil-less tomatoes in three different Italian areas, with computational aspects and methods of the TRNSYS simulation. Values of climatic parameters are obtained as a responce for the feasibility of the cultivation under PV modules. The results show energy savings both for heating and cooling due to PV panels, adding a new reason for the realization of these systems.

The Efficiency of Geothermal Heat Pumps With Vertical Ground Heat Exchangers: A Simulation Under Iraqi Conditions

2010 ◽  
Author(s):  
Nazar F. Antwan ◽  
Iyd E. Maree
Keyword(s):  
Heat Exchangers ◽  
Energy Savings ◽  
Heat Pumps ◽  
Domestic Water ◽  
Geothermal Heat ◽  
Local Climate ◽  
Climate Conditions ◽  
The North ◽  
Heating And Cooling ◽  
Ground Source

Geothermal heat pumps with ground source heat exchangers have been widely used for heating and cooling homes as well as for domestic water heating. A study on a small house in Erbil-Iraq was conducted to assess energy savings when using GHPs with closed loop ground source heat exchangers as compared with air-to-air heat pumps. Local climate conditions and soil properties of Erbil located in the north of Iraq were used. The simulation was performed using TRNSYS-16 software. The results of this study show that we can reduce the energy used for heating and cooling by 39% during annual when using GHP. The simulation also showed that the average COP for heating is 2.9 and for cooling is 2.6 when using air to air heat pumps and the average COP for heating is 5.6 and 3.6 for cooling when using GHP. This reduction in energy reduces the CO2 emission as it reduces energy consumption.

Buildings

2017 ◽  
Author(s):  
Peter Rez
Keyword(s):  
Heat Transfer ◽  
Heat Pump ◽  
Energy Efficient ◽  
Energy Use ◽  
Fossil Fuel ◽  
Local Climate ◽  
Heating And Cooling ◽  
The Difference ◽  
As If

Most of the energy used by buildings goes into heating and cooling. For small buildings, such as houses, heat transfer by conduction through the sides is as much as, if not greater than, the heat transfer from air exchanges with the outside. For large buildings, such as offices and factories, the greater volume-to-surface ratio means that air exchanges are more significant. Lights, people and equipment can make significant contributions. Since the energy used depends on the difference in temperature between the inside and the outside, local climate is the most important factor that determines energy use. If heating is required, it is usually more efficient to use a heat pump than to directly burn a fossil fuel. Using diffuse daylight is always more energy efficient than lighting up a room with artificial lights, although this will set a limit on the size of buildings.

scholarly journals Towards Sustainable Energy Retrofitting, a Simulation for Potential Energy Use Reduction in Residential Buildings in Palestine

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3876
Author(s):  
Sameh Monna ◽  
Adel Juaidi ◽  
Ramez Abdallah ◽  
Aiman Albatayneh ◽  
Patrick Dutournie ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Energy Use ◽  
Energy Savings ◽  
Residential Buildings ◽  
Residential Building ◽  
Simulation Models ◽  
Water Heating ◽  
Heating And Cooling ◽  
Space Cooling ◽  
Cooling Loads

Since buildings are one of the major contributors to global warming, efforts should be intensified to make them more energy-efficient, particularly existing buildings. This research intends to analyze the energy savings from a suggested retrofitting program using energy simulation for typical existing residential buildings. For the assessment of the energy retrofitting program using computer simulation, the most commonly utilized residential building types were selected. The energy consumption of those selected residential buildings was assessed, and a baseline for evaluating energy retrofitting was established. Three levels of retrofitting programs were implemented. These levels were ordered by cost, with the first level being the least costly and the third level is the most expensive. The simulation models were created for two different types of buildings in three different climatic zones in Palestine. The findings suggest that water heating, space heating, space cooling, and electric lighting are the highest energy consumers in ordinary houses. Level one measures resulted in a 19–24 percent decrease in energy consumption due to reduced heating and cooling loads. The use of a combination of levels one and two resulted in a decrease of energy consumption for heating, cooling, and lighting by 50–57%. The use of the three levels resulted in a decrease of 71–80% in total energy usage for heating, cooling, lighting, water heating, and air conditioning.

scholarly journals A Study of Optimal Specifications for Light Shelves with Photovoltaic Modules to Improve Indoor Comfort and Save Building Energy

2021 ◽  
Vol 18 (5) ◽  
pp. 2574
Author(s):  
Heangwoo Lee ◽  
Xiaolong Zhao ◽  
Janghoo Seo
Keyword(s):  
Energy Savings ◽  
Building Energy ◽  
Energy Performance ◽  
Building Energy Efficiency ◽  
Efficiency Change ◽  
Photovoltaic Modules ◽  
Heating And Cooling ◽  
Pv Module ◽  
Pv Modules ◽  
Indoor Comfort

Recent studies on light shelves found that building energy efficiency could be maximized by applying photovoltaic (PV) modules to light shelf reflectors. Although PV modules generate a substantial amount of heat and change the consumption of indoor heating and cooling energy, performance evaluations carried out thus far have not considered these factors. This study validated the effectiveness of PV module light shelves and determined optimal specifications while considering heating and cooling energy savings. A full-scale testbed was built to evaluate performance according to light shelf variables. The uniformity ratio was found to improve according to the light shelf angle value and decreased as the PV module installation area increased. It was determined that PV modules should be considered in the design of light shelves as their daylighting and concentration efficiency change according to their angles. PV modules installed on light shelves were also found to change the indoor cooling and heating environment; the degree of such change increased as the area of the PV module increased. Lastly, light shelf specifications for reducing building energy, including heating and cooling energy, were not found to apply to PV modules since PV modules on light shelf reflectors increase building energy consumption.

Impact of Climbing Plants on Buildings and Their Environment

2018 ◽  
pp. 297-309
Author(s):  
Jacek Borowski
Keyword(s):  
Plant Growth ◽  
Energy Savings ◽  
Economic Benefits ◽  
Climbing Plants ◽  
Heating And Cooling ◽  
Home Heating ◽  
The Impact

In this chapter, the impact of climbing plants on facades of buildings and their surroundings is presented. Benefits and risks of plant growth on the walls are discussed with respect to their durability. Economic benefits from the presence of vines are shown including energy savings for home heating and cooling. Additionally, the phytoremediation (cleaning up the environment by plants) properties of vines are describe. It should be stated that climbing plants can contribute to damage only in places where facades are damaged, plaster cracked, or where plants are incorrectly planted.

scholarly journals Modeling of an Aerogel-Based “Thermal Break” for Super-Insulated Window Frames

Buildings ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 60 ◽  
Author(s):  
Alessandro Cannavale ◽  
Francesco Martellotta ◽  
Umberto Berardi ◽  
Chiara Rubino ◽  
Stefania Liuzzi ◽  
...  
Keyword(s):  
Potential Role ◽  
Energy Savings ◽  
Building Stock ◽  
Insulating Materials ◽  
Existing Building ◽  
Heating And Cooling ◽  
Research Activities ◽  
Optimal Exploitation ◽  
Indoor Comfort ◽  
Window Frames

Research activities in the field of innovative fixtures are continuously aiming at increasing their thermal and optical performances to offer optimal exploitation of daylight and solar gains, providing effective climate screen, according to increasing standards for indoor comfort and energy saving. Within this work, we designed an innovative aerogel-based “thermal break” for window frames, so as to consistently reduce the frame conductance. Then, we compared the performance of this new frame both with currently used and obsolete frames, present in most of the existing building stock. Energy savings for heating and cooling were assessed for different locations and confirmed the potential role played by super-insulating materials in fixtures for extremely rigid climates.

Energy Saving by ESCO (Energy Service Company) Project in Japanese Hospital

2009 ◽  
Author(s):  
S. Okamoto
Keyword(s):  
Energy Demand ◽  
Energy Savings ◽  
High Efficiency ◽  
Hospital Setting ◽  
Electrical Heating ◽  
Public Network ◽  
Service Company ◽  
Heating And Cooling ◽  
Energy Service ◽  
Energy Service Company

This paper describes a study starting from an analysis of typical energy demand profiles in a hospital setting followed by the case study of a cogeneration system (CGS) by an ESCO (Energy Service Company) project. The concept is a future autonomous system for the combined generation of electrical, heating and cooling energy in the hospital. The driving cogeneration units are two high-efficiency gas engines; this is used to produce the electrical and heat energy. Gas engine is used as a driving unit because of high needs for electrical and heating energy. The natural gas-fuelled reciprocating engine is used to generate 735kW of power. In our case electrical energy will be used only in the Hospital. A deficit in electricity can be also purchased from the public network. The generated steam will be used to drive three steam-fired absorption chillers and delivered to individual consumers of heat. This system is capable of doing simultaneous heating and cooling. No obstacles were recognized for the technical feasibility of CGS. The average ratio between electric and thermal load in the Hospital is suitable to make CGS system operate. An analysis performed for a non-optimized CGS system predicted a large potential for energy savings.

scholarly journals Comparison Evaluations of VRF and RTU Systems Performance on Flexible Research Platform

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Je-hyeon Lee ◽  
Piljae Im ◽  
Jeffrey D. Munk ◽  
Mini Malhotra ◽  
Min-seok Kim ◽  
...  
Keyword(s):  
Energy Use ◽  
Energy Savings ◽  
Thermal Conditions ◽  
The United States ◽  
Energy Performance ◽  
Coefficient Of Performance ◽  
Part Load ◽  
Variable Air Volume ◽  
Heating And Cooling ◽  
Load Conditions

The energy performance of a variable refrigerant flow (VRF) system was evaluated using an occupancy-emulated research building in the southeastern region of the United States. Full- and part-load performance of the VRF system in heating and cooling seasons was compared with a conventional rooftop unit (RTU) variable-air-volume system with electric resistance heating. During both the heating and cooling seasons, full- and part-load conditions (i.e., 100%, 75%, and 50% thermal loads) were maintained alternately for 2 to 3 days each, and the energy use, thermal conditions, and coefficient of performance (COP) for the RTU and VRF system were measured. During the cooling season, the VRF system had an average COP of 4.2, 3.9, and 3.7 compared with 3.1, 3.0, and 2.5 for the RTU system under 100%, 75%, and 50% load conditions and resulted in estimated energy savings of 30%, 37%, and 47%, respectively. During the heating season, the VRF system had an average COP ranging from 1.2 to 2.0, substantially higher than the COPs of the RTU system, and resulted in estimated energy savings of 51%, 47%, and 27% under the three load conditions, respectively.

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