Space Heating

The renewables-based energy system represents a unique opportunity to meet climate goals while increasing economic growth, creating new employment opportunities and enhancing human welfare. Hence the role of renewable energy has been assuming increasing significance in recent times with the growing concern for the energy security. This paper overviews the current trends of renewable energy globally and particularly in India as well as their growth and environmental issues.

Almost 60% of the world's electricity is consumed in residential and commercial buildings. At the national level, energy use in buildings typically accounts for 20-40% of individual country total final energy use, with the world average being around 30%. In many developing and industrialized country, escalation of energy demand can be solved by using locally available and sustainable low-enthalpy geothermal resources. Certain geological locations provide low enthalpy resources that are best adapted for direct utilization. These are the socalled plate boundaries which take the form of spreading zones or rift zones. These zones will remain the main areas of interest until the time when Hot Sedimentary Aquifer (HSA) technology might allow geothermal production virtually everywhere in the world. Consequently, the countries that are positioned within these zones may become more independent from fossil fuel import because of the possibility of using indigenous energy. Direct-use of geothermal energy is the most versatile and common forms of utilizing geothermal energy. The total installed capacity, reported through the end of 2014 for geothermal direct utilization worldwide is 70,329 Mega Watt, a 45.0% increase over World Geothermal Congress (WGC) 2010, growing at an annual compound rate of 7.7%. The installed capacity now totals 7,556 Mega Watt and the annual energy use is 88,222 Tera Joule per year. In comparison, 88% of the total installed capacity and 89% of the annual energy use is in district heating (28 countries). While, the installed capacity of space cooling is 360 Mega Watt and the annual energy use is 2,600 Tera Joule per year. Space heating can be provided by means of pumped wells, heat pump, or through the use of down-hole heat exchangers. A space heater is intended to heat a space directly, unlike a central heating furnace or boiler which distributes heat to the house through a system of ducts or pipes. Geothermal absorption refrigeration units make use of the boiling temperature of a liquid depends on pressure; heat is transferred from the environment when a liquid boils, and the result is space cooling.

Because of acute shortage of electric power, especially the energy consumed for heating and cooling in the official working hours for government departments and the private sectors grew the idea our design solar space heating system operate on solar power only and for the official working hours because the most of solar energy systems are auxiliary power beside the electric power. In this research, the system is designed for heating of a meetings hall for a period of six hours. The research has been carried out in Iraq under the ministry of science and technology during winter (2011 -2012) for the period from November 2011 to March 2012.The research was started with the design calculations for the required space heating load and this value has been calculated (2092.2W/day).The energy provided by evacuated tubes solar collectors that suit the heating load required and its value (46332kJ/day).The readings have been taken for every ten minutes by using data logger, measuring and recording device and store data of solar radiation rate (solar meter) respectively. The study showed that how the system compensate (9.6 kWh/day) instead of the electric power that consumed for space heating load for hall of area 47.5m 2 .

In this paper a survey of the various types of solar thermal collectors and applications is presented. Initially, an analysis of the environmental problems related to the use of conventional sources of energy is presented and the benefits offered by renewable energy systems are outlined. A historical introduction into the uses of solar energy is attempted followed by a description of the various types of collectors including flat-plate, compound parabolic, evacuated tube, parabolic trough, Fresnel lens, parabolic dish and heliostat field collectors. This is followed by an optical, thermal and thermodynamic analysis of the collectors and a description of the methods used to evaluate their performance. Typical applications of the various types of collectors are presented in order to show to the reader the extent of their applicability. These include solar water heating, which comprise thermosyphon, integrated collector storage, direct and indirect systems and air systems, space heating and cooling, which comprise, space heating and service hot water, air and water systems and heat pumps, refrigeration, industrial process heat, which comprise air and water systems and steam generation systems, desalination, thermal power systems, which comprise the parabolic trough, power tower and dish systems, solar furnaces, and chemistry applications. As can be seen solar energy systems can be used for a wide range of applications and provide significant benefits, therefore, they should be used whenever possible. q

Because of acute shortage of electric power, especially the energy consumed for heating and cooling in the official working hours for government departments and the private sectors grew the idea our design solar space heating system operate on solar power only and for the official working hours because the most of solar energy systems are auxiliary power beside the electric power. In this research, the system is designed for heating of a meetings hall for a period of six hours. The research has been carried out in Iraq under the ministry of science and technology during winter (2011 -2012) for the period from November 2011 to March 2012.The research was started with the design calculations for the required space heating load and this value has been calculated (2092.2W/day).The energy provided by evacuated tubes solar collectors that suit the heating load required and its value (46332kJ/day).The readings have been taken for every ten minutes by using data logger, measuring and recording device and store data of solar radiation rate (solar meter) respectively. The study showed that how the system compensate (9.6 kWh/day) instead of the electric power that consumed for space heating load for hall of area 47.5m 2 .

In this paper a survey of the various types of solar thermal collectors and applications is presented. Initially, an analysis of the environmental problems related to the use of conventional sources of energy is presented and the benefits offered by renewable energy systems are outlined. A historical introduction into the uses of solar energy is attempted followed by a description of the various types of collectors including flat-plate, compound parabolic, evacuated tube, parabolic trough, Fresnel lens, parabolic dish and heliostat field collectors. This is followed by an optical, thermal and thermodynamic analysis of the collectors and a description of the methods used to evaluate their performance. Typical applications of the various types of collectors are presented in order to show to the reader the extent of their applicability. These include solar water heating, which comprise thermosyphon, integrated collector storage, direct and indirect systems and air systems, space heating and cooling, which comprise, space heating and service hot water, air and water systems and heat pumps, refrigeration, industrial process heat, which comprise air and water systems and steam generation systems, desalination, thermal power systems, which comprise the parabolic trough, power tower and dish systems, solar furnaces, and chemistry applications. As can be seen solar energy systems can be used for a wide range of applications and provide significant benefits, therefore, they should be used whenever possible. q

Various energy sources can be used for room heating, among which waste heat utilization has significantly improved in recent years. However, the majority of applicable waste heat resources are high-grade or stable thermal energy, while the low-grade or unstable waste heat resources, especially low-temperature industrial residual water (IRW), are insufficiently used. A thermal energy storage (TES) unit with paraffin wax as a phase change material (PCM) is designed to solve this problem in a pharmaceutical plant. The mathematical models are developed to simulate the heat storage and release processes of the TES unit. The crucial parameters in the recurrence formulae are determined: the phase change temperature range of the paraffin wax used is 47 to 56 °C, and the latent heat is 171.4 kJ/kg. Several thermal behaviors, such as the changes of melting radius, solidification radius, and fluid temperature, are simulated. In addition, the amount of heat transferred, the heat transfer rate, and the heat storage efficiency are discussed. It is presented that the medicine production unit could save 10.25% of energy consumption in the investigated application.

When it comes to residential buildings, there are several stochastic parameters, such as renewable energy production, outdoor air conditions, and occupants’ behavior, that are hard to model and predict accurately, with some being unique in each specific building. This increases the complexity of developing a generalizable optimal control method that can be transferred to different buildings. Rather than hard-programming human knowledge into the controller (in terms of rules or models), a learning ability can be provided to the controller such that over the time it can learn by itself how to maintain an optimal operation in each specific building. This research proposes a model-free control framework based on Reinforcement Learning that takes into account the stochastic hot water use behavior of occupants, solar power generation, and weather conditions, and learns how to make a balance between the energy use, occupant comfort and water hygiene in a solar-assisted space heating and hot water production system. A stochastic-based offline training procedure is proposed to give a prior experience to the agent in a safe simulation environment, and further ensure occupants comfort and health when the algorithm starts online learning on the real house. To make a realistic assessment without interrupting the occupants, weather conditions and hot water use behavior are experimentally monitored in three case studies in different regions of Switzerland, and the collected data are used in simulations to evaluate the proposed control framework against two rule-based methods. Results indicate that the proposed framework could achieve an energy saving from 7% to 60%, mainly by adapting to solar power generation, without violating comfort or compromising the health of occupants.

Methods to select the outdoor design temperature (ODT) for heating load calculation specified in current design codes in different countries are firstly discussed. Then a new method namely Stochastic Analysis is presented to determine the outdoor synthetic temperature (OST), which fully considers the randomness of weather and internal casual gains, and the thermal performance of buildings. The concept of OST enables the design of space heating system to be the trade-off between economics and risk. Finally, case studies of the influence of different building components on OST of a residential room in Beijing have been studied, which shows that OST depends upon building structures as well as weather conditions. It is recommended that OST rather than ODT should be employed in heating load calculation hence, sizing equipment for space heating systems.

Solar air collectors have various applications: on the one hand, they can be used for air heating in cold seasons; on the other hand they can be used in summer to evacuate the warm and polluted air from residential, offices, industrial, and commercial buildings. The paper presents experimental results of a solar collector air, under the climatic conditions of the Southeastern Europe. The relationships between the direct solar irradiation, the resulting heat flow, the air velocity at the outlet, the air flow rate, the nominal regime of the collector and the efficiency of conversion of solar energy into thermal energy are all highlighted. Thus, it was shown that after a maximum 50 min, solar air collectors, with baffles and double air passage can reach over 50% efficiency for solar irradiation of 900-1000 W/m 2. The article also presents a mathematical model and the results of a computational program that allows sizing solar collectors for the transfer of air, with the purpose of improving the natural ventilation of buildings. The article is completed with case studies, sizing the area to be covered with solar collectors, to ensure ventilation of a house with two floors or for an office building. In addition, the ACH (air change per hour) coefficient was calculated and compared.

The objective of this work is to quantify the resultant savings across the EU from the optimization of existing system components in domestic space heating distribution systems to maintain comfort levels. Heat energy savings are shown to range from 1% to 19% depending on dwelling type, age, location and initial specific heat energy consumption. Total potential savings across the sector amount 22.6 Mtoe, a reduction of 7.3%; 53% of these from a reduction in pumping power required by heating distribution systems and 47% of these from a reduction in the heat energy consumed by heating systems. The carbon abatement potential is estimated to be 496 million tonnes of CO 2 equivalent. Regulatory changes to the domestic replacement and maintenance industry are required for these low-cost, high impact and highly applicable energy saving measures to be adopted more extensively.

This paper examines the formation of heating practices at the time of moving house. Interviews on occupant changes in Finnish single-family houses with a focus on heating arrangements and thermal comfort reveal that practice formation in and around occupant changes is a complex process of aligning elements where the house stands out as a coordinative and coordinated aggregate. As houses pass from one set of occupants to the next, they carry practices and delineate new ways of operation to the new occupants. The study demonstrates the temporal unfolding of the hidden complexity to what seems like a straightforward process of residents interacting with a new heating system and home. The findings contribute to the understanding of the domestic sphere as a space for practice formation.

The objective of this work is to quantify the resultant savings across the EU from the optimization of existing system components in domestic space heating distribution systems to maintain comfort levels. Heat energy savings are shown to range from 1% to 19% depending on dwelling type, age, location and initial specific heat energy consumption. Total potential savings across the sector amount 22.6 Mtoe, a reduction of 7.3%; 53% of these from a reduction in pumping power required by heating distribution systems and 47% of these from a reduction in the heat energy consumed by heating systems. The carbon abatement potential is estimated to be 496 million tonnes of CO 2 equivalent. Regulatory changes to the domestic replacement and maintenance industry are required for these low-cost, high impact and highly applicable energy saving measures to be adopted more extensively.

In this paper a survey of the various types of solar thermal collectors and applications is presented. Initially, an analysis of the environmental problems related to the use of conventional sources of energy is presented and the benefits offered by renewable energy systems are outlined. A historical introduction into the uses of solar energy is attempted followed by a description of the various types of collectors including flat-plate, compound parabolic, evacuated tube, parabolic trough, Fresnel lens, parabolic dish and heliostat field collectors. This is followed by an optical, thermal and thermodynamic analysis of the collectors and a description of the methods used to evaluate their performance. Typical applications of the various types of collectors are presented in order to show to the reader the extent of their applicability. These include solar water heating, which comprise thermosyphon, integrated collector storage, direct and indirect systems and air systems, space heating and cooling, which comprise, space heating and service hot water, air and water systems and heat pumps, refrigeration, industrial process heat, which comprise air and water systems and steam generation systems, desalination, thermal power systems, which comprise the parabolic trough, power tower and dish systems, solar furnaces, and chemistry applications. As can be seen solar energy systems can be used for a wide range of applications and provide significant benefits, therefore, they should be used whenever possible. q

Solar air collectors have various applications: on the one hand, they can be used for air heating in cold seasons; on the other hand they can be used in summer to evacuate the warm and polluted air from residential, offices, industrial, and commercial buildings. The paper presents experimental results of a solar collector air, under the climatic conditions of the Southeastern Europe. The relationships between the direct solar irradiation, the resulting heat flow, the air velocity at the outlet, the air flow rate, the nominal regime of the collector and the efficiency of conversion of solar energy into thermal energy are all highlighted. Thus, it was shown that after a maximum 50 min, solar air collectors, with baffles and double air passage can reach over 50% efficiency for solar irradiation of 900-1000 W/m 2. The article also presents a mathematical model and the results of a computational program that allows sizing solar collectors for the transfer of air, with the purpose of improving the natural ventilation of buildings. The article is completed with case studies, sizing the area to be covered with solar collectors, to ensure ventilation of a house with two floors or for an office building. In addition, the ACH (air change per hour) coefficient was calculated and compared.

The rate of increase in energy consumption and high costs in addition to the depletion of existing resources has a significant impact on our standard of living for next generations. In this case, the priority is to develop alternative cost-effective sources for powering the residential and non-residential buildings. This paper proposes and develops a design of a modified small two-story residential solar house for a medium-sized family located in Cairo, Egypt. This modified solar house meets almost all its energy demands including space heating by using solar air collector with a pebble storage unit in winter and a summer cooling system using wind catcher theory. Hot water is obtained throughout the day by using a steel sheltered water storage tank with a capacity of 1000 liter. Finally, the proposed heating system of the solar house is sized and modeled.

Because of acute shortage of electric power, especially the energy consumed for heating and cooling in the official working hours for government departments and the private sectors grew the idea our design solar space heating system operate on solar power only and for the official working hours because the most of solar energy systems are auxiliary power beside the electric power. In this research, the system is designed for heating of a meetings hall for a period of six hours. The research has been carried out in Iraq under the ministry of science and technology during winter (2011 -2012) for the period from November 2011 to March 2012.The research was started with the design calculations for the required space heating load and this value has been calculated (2092.2W/day).The energy provided by evacuated tubes solar collectors that suit the heating load required and its value (46332kJ/day).The readings have been taken for every ten minutes by using data logger, measuring and recording device and store data of solar radiation rate (solar meter) respectively. The study showed that how the system compensate (9.6 kWh/day) instead of the electric power that consumed for space heating load for hall of area 47.5m 2 .