Heat pumps can be considered one of the key technologies to meet the building stock decarbonization target set by Europe. Especially in warm locations, many households have already incurred costs for the installation of air-to-air heat pumps, but, in...
The air-reversed Brayton cycle produces charming, environmentally friendly effects by using air as its refrigerant and has potential energy efficiency in applications related to space heating and building heating. However, there exist several types o...
The finned-tube heat exchanger (FTHX) works better with more circuits as an evaporator but fewer as a condenser in air-source heat pumps (ASHPs). In this article, a reversely variable circuitry is proposed to address this contradiction. The effects o...
This paper presents a reversible heat pump based on CO2 as the refrigerant, able to provide heating, cooling, and domestic hot water to high energy demand buildings. The unit was developed and tested under the EU H2020 project MultiPACK, which has th...
During annual operation, a heat pump produces both heating and cooling effects, so it would be of great advantage to store one of the two to be then used when it is necessary. To do this, a seasonal energy storage is necessary. This paper presents re...
Reversible heat pumps are increasingly adopted for meeting the demand for space heating and cooling in buildings. These technologies will play a key role not only in the decarbonization of space air conditioning but also in the development of 100% re...
In recent years, modern and energy-saving solutions, such as heat pumps or solar collectors, have enjoyed great popularity in the heating and cooling sector, which is conditioned by political and environmental factors. The aim of this paper was to an...
Exergy-based methods provide engineers with the best information with respect to options for improving the overall thermodynamic efficiency of an energy conversion system. This paper presents the results of an advanced exergy analysis of an air-to-wa...
Redox materials have been investigated for various thermochemical processing applications including solar fuel production (hydrogen, syngas), ammonia synthesis, thermochemical energy storage, and air separation/oxygen pumping, while involving concent...
Heating, cooling and domestic hot water (DHW) are responsible for the largest share of energy use in residential buildings in Spain and play an important role in the implementation of nearly zero-energy buildings (NZEB). Building Information Modellin...
Frost deposits on the outdoor heat exchanger of an air source heat pump (ASHP) air conditioner and reduces its capacity during winter operation. However, the prevailing reverse-cycle defrosting (RCD) turns the indoor heat exchanger into an evaporator...
Required refrigerant charge in heat pump systems with propane is analyzed. Two systems are compared: the first a direct heat pump, with fin-and-tube heat exchangers, and the second an indirect system, with plate heat exchangers with an additional bri...
The European Parliament has imposed to reduce by 2030 whole HFC emissions by at least two-thirds with respect to 2014 levels. With the aim of contributing to determine the energy and environmental advantages of refrigerants alternative to R-410A, thi...
The evolution of district heating networks is moving toward low temperatures in heat distribution with so called 4th generation networks. However, the lowest heat transfer fluid temperatures in district heating are achieved through ultra-low temperat...
In this paper, a new R744 heat pump system is studied. The gas cooler, evaporator, indoor heat core, and indoor gas cooler are all micro-channel heat exchangers. The R744 high pressure system adopts a combination of an accumulator and internal heat e...
In this paper, the performance of an innovative micro-combined cooling, heating, and power (CCHP) system, based on an internal combustion engine fueled with syngas from woody biomass, is analyzed. In particular, a numerical model, which considers a d...
Energy needs of air conditioning systems are constantly growing worldwide, due to climate change and growing standards of buildings. Among the possible systems, solar heating and cooling based on reversible heat pumps and thermally driven chillers ar...
Energy consumed for air conditioning in residential and tertiary sectors accounts for a large share of global use. To reduce the environmental impacts burdening the covering of such demands, the adoption of renewable energy technologies is increasing...
In the European Union (EU), buildings are responsible for about 40% of the total final energy consumption, and 36% of the European global CO2 emissions. The European Commission released directives to push for the enhancement of the buildings energy p...
This study proposes and evaluates a car seat-integrated heat pump as localized air conditioning system for electric vehicles (EVs). The proposed system uses R1234yf and comprises a compressor, microchannel heat exchangers, an electronic expansion val...
Efficiently storing energy on a large scale poses a major challenge and one that is growing in importance with the increasing share of renewables in the energy mix. The only options at present are either pumped hydro or compressed air storage. One no...
Heat pump (HP) technology has been widely adopted in electric vehicles (EVs) for cabin and battery heating in cold weather due to its high efficiency. However, when an HP works under low ambient temperatures and high humidity, frost grows on the surf...
In order to improve the low efficiency and malfunction caused by the FWRV (four-way reversing valve) when the working mode of the heat pump air conditioning system changes in refrigeration and heating, it is of great significance to study the structu...
A major issue in the renewable energy supply of buildings is to establish a simultaneity of the fluctuating renewable energy generation and the energy consumption in buildings. This work provides a new case for a better understanding of how to establ...
In its usual definition, exergy cancels out at the ambient temperature which is thus taken both as a constant and as a reference. When the fluctuations of the ambient temperature, obviously real, are considered, the temperature where exergy cancels o...
The pressing demand for clean water worldwide has increased attention to developing innovative desalination processes. In this work, the second law of thermodynamics is used to examine and assess two coupled desalination systems: a separation-based r...
This research work synthetizes the energy, economic, and environmental aspects of a novel configurational analysis of four polygeneration schemes designed to fulfill the demands of a multi-family building that includes 12 dwellings. The design aims t...
Previous studies have indicated that a basic frost layer negatively affects the heat-transfer efficiency and is difficult to remove using a single ultrasonic transducer. Herein, an ultrasonic phased array technology is proposed for evaporator coil de...
The Clean Energy for all Europeans Package pushes for the diffusion of renewable energy communities, introducing their definition in the European legislative framework. Following this interest, this paper analyses the energy and environmental perform...
This investigation attempts to develop a tower solar collector-based system designed for the cogeneration of cooling and desalination. The traditional organic Rankine cycle (ORC) integrated with the ejector refrigeration cycle generates limited power...
More attention on renewable energy has been attracted after the achievement of Paris Agreement against climate change. Solar-based technology is supposed to be one of the most promising green energy technologies for residential buildings since its wi...
In line with the decarbonization of the domestic sector to meet the 2050 climate neutrality targets, this paper describes the energy, economic, and environmental analysis of a set of different novel configurations of polygeneration installations to p...
An existing idle cooling tower can be reversibly used as a heat-source tower (HST) to drive a heat pump (HP) in cold seasons, with calcium chloride (CaCl2) aqueous solution commonly selected as the secondary working fluid in an indirect system due to...
This paper reports on modelling outcomes for improvements to building energy performance in Indonesia. Long-term climate effects due to building energy demand and carbon emissions are also considered. The global change assessment model (GCAM) was use...