Michele Bottarelli

Michele Bottarelli
University of Ferrara | UNIFE · Department of Architecture

MSc

About

76
Publications
16,964
Reads
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465
Citations
Introduction
Research: ground-coupled heat pumps, phase change materials, underground thermal energy storage, vented roofs, porous media. Teaching: Applied Thermal Engineering, Renewable Energy.
Additional affiliations
October 2019 - present
University of Ferrara
Position
  • Professor (Associate)
Description
  • Applied Physics
November 2008 - September 2019
University of Ferrara
Position
  • Professor (Assistant)
Description
  • Researcher in Applied Physics
October 2008 - present
University of Ferrara
Position
  • Professor
Description
  • Applied Thermal Engineering, Renewable Energies

Publications

Publications (76)
Article
Full-text available
In hot climates, ventilated pitched roofs help dissipating the excess heat, thus reducing the cooling energy demand. The key factor is the so-called Above Sheathing Ventilation (ASV) that depends on the air entering and leaving at the eaves, ridge and the gaps among tiles. A strategy for increasing the ASV is the enhancement of the roof air permeab...
Article
The increasing energy demand for heating and cooling is leading to the development of new strategies for reducing energy consumption and greenhouse gas emissions. Phase change materials applied on the building envelope can act as a heat modulation passive cooling strategy, reducing the energy requirement. An essential aspect for an effective applic...
Article
The construction sector accounts for more than one-third of the global energy consumption. Ventilated roofs and facades are among the adopted strategies to improve the efficiency of the building envelope: air flowing in cavities under the cladding layer, in fact, is particularly effective in hot summers for the reduction of the incoming heat flow d...
Article
The behaviour of a multi-source heat pump system coupled with phase change materials (PCMs) is discussed in this manuscript, as based on selected data collected during one-year testing at the TekneHub Laboratory of the University of Ferrara (Italy), as a synergic prototype setup of two European projects: IDEAS, an H2020 project, and CLIWAX, an EFDR...
Conference Paper
Ground Source Heat Pumps are promising technologies that can contribute to decarbonize the space heating and cooling in buildings. In this work, a particular ground heat exchanger for residential buildings is studied via numerical models. The system consists of a helical heat exchanger immersed in a water tank (cell) buried into the ground. A sensi...
Article
Full-text available
The building sector is responsible for a third of the global energy consumption and a quarter of greenhouse gas emissions. Phase change materials (PCMs) have shown high potential for latent thermal energy storage (LTES) through their integration in building materials, with the aim of enhancing the efficient use of energy. Although research on PCMs...
Conference Paper
The construction sector represents more than one-third of the global energy consumption, and a consistent part of the building stock is made of historical buildings. The application of phase change materials (PCMs) mixed within the plaster represents a tangible possibility to improve the performances of historical buildings without violating any le...
Article
Full-text available
The construction sector is among the major players responsible for global energy consumption and therefore related emissions, both because of the constantly increasing indoor air quality standard which requires increasingly higher energy demands as well as the great share of historical buildings which are now obsolete and are not up to date with cu...
Article
Significant energy savings and thermal comfort improvement related to radiant floor systems may not be achieved when underfloor heating/cooling is adopted in lightweight building envelopes. Phase change materials (PCMs) are suitable candidates for providing the necessary thermal inertia with a minimum effect on the construction technology. Impactin...
Article
The improvement of energy efficiency in the building sector is one of the most promising actions for achieving the energy and environmental goals of the European Community. The deep retrofit of buildings is obviously the best solution in terms of energy performance result. When the deep retrofit is not allowed or possible, the simple maintenance of...
Article
The study of swimming behavior is an important part of fish biology research and the swim tunnel is used to study swimming performance as well as metabolism of fish. In this investigation, we have developed a user-friendly, automated, modular, and low-cost swim tunnel that permits to study the performance of one or more fish separately, as well as...
Article
Full-text available
The current paper presents the state-of-the-art of the ongoing IDEAS research project, funded under the Horizon 2020 EU framework programme. The project involves fourteen partners from six European countries and proposes a multi-source cost-effective renewable energy system for the decarbonisation of the building envelope. The system features a rad...
Article
Full-text available
Radiant floor systems enhanced with Phase Change Materials (PCMs) could achieve significant energy savings while improving the thermal comfort of occupants in lightweight buildings. Effective integration of PCMs typically requires customised solutions based on a comprehensive analysis due to their complex nature. The objective of the present study...
Article
Radiant floor systems enhanced with Phase Change Materials (PCMs) could achieve significant energy savings while improving the thermal comfort of occupants in lightweight buildings. Effective integration of PCMs typically requires customised solutions based on a comprehensive analysis due to their complex nature. The objective of the present study...
Article
In this study two phase change materials (PCMs) mixed with sand were evaluated for distributed latent heat thermal energy storage (LHTES) coupled with a novel Flat-Panel ground heat exchanger (GHE) for shallow geothermal applications. N-Octadecane and a commercial paraffin-based PCM were mixed (30% v/v) separately with sand, which is commonly used...
Experiment Findings
Full-text available
A real scale hydronic radiant floor integrated with macro encapsulated PCM was installed in a set up building. Hydrated salts with different melting temperatures were chosen: 27°C for space heating and 21°C for space cooling. The different PCM containers were arranged above the mortar alternately in order to avoid any located inhomogeneity of the f...
Article
Full-text available
Several passive cooling design techniques are known for reducing solar heat gain through building envelope in summer season. These include the use of phase change materials (PCM), which has received an increased attention over the last years, and the strategy of increasing the above-sheathing ventilation (ASV) in ventilated roofs. However, few stud...
Article
Full-text available
Installation costs of ground heat exchangers (GHEs) make the technology based on ground-coupled heat pumps (GCHPs) less competitive than air source heat pumps for space heating and cooling in mild climates. A smart solution is the dual source heat pump (DSHP) which switches between the air and ground to reduce frosting issues and save the system ag...
Conference Paper
The application of Phase Change Materials (PCMs) in radiant floor heating considerably enhance their energy saving potential and the improvement of indoor thermal comfort as well. The study aims at investigating the energy performance of a PCM integrated hydronic underfloor heating system in dry and wet sand conditions. Experimental and numerical a...
Experiment Findings
Full-text available
Experimental tests conducted on an hydronic radiant floor enhanced with PCM containers. The impact of using dry and wet sand on thermal performance was investigated. The behaviour of the system including temporal changes in temperature and heat flux were analysed.
Conference Paper
Dual source heat pumps (DSHPs) combine air and ground as mutual complementary thermal sources for invertible heat pump systems by switching between them, in order to reduce frosting issues and avoid too low/high temperatures affecting air-mode operation by using the ground thermal source [1]. As the ground thermal source is not continuously exploit...
Conference Paper
International Energy Agency has recently warned about the fast growing of space cooling in buildings, especially in the hottest parts of the world. In this context, different passive cooling techniques, such as the use of phase change materials (PCM) in building envelope and Above Sheathing Ventilation (ASV) systems, have received an increased atte...
Conference Paper
The effect of high infrared (IR) reflective coatings of interior building surfaces is experimentally studied. By mean of a test rig heated with a black body at 67.5°C, temperatures and heat fluxes have been monitored for two different kinds of IR-reflective paints in comparison with the same paint without IR-reflective additive. Results of IR-refle...
Article
Full-text available
The paper reports and analysis the preliminary tests of a dual-source heat pump prototype (DSHP) as experimental airconditioning system for a room at the University of Ferrara (UNIFE), Italy. The prototype is composed of a common air-to-air heat pump, a geothermal closed loop, and a novel kit for coupling the air-source heat pump with the closed lo...
Article
Ground-coupled and air-source heat pumps (GCHPs and ASHPs, respectively)are regarded as energy efficient systems for air conditioning. Their coupling in a dual air and ground source heat pump (DSHP)can offer a further performance improvement by reducing the drawbacks of each standalone technology. In the present study, a DSHP coupled with a Flat-Pa...
Article
Full-text available
The article is a product of the COST RELY Action, it is a glossary: definitions related to renewable energy and landscape quality.
Article
The refrigerator is one of the most essential domestic appliances and causes considerable energy consumption every year. The efficiency of a normal household refrigerator is significantly affected by the heat-insulating property of the thermal barrier of the freezer due to its low inner temperature. In this study, a novel refrigerator with a loop t...
Article
Full-text available
Air-source and ground coupled heat pumps are depicted as energy efficient systems. Nevertheless, the ground coupling incurs in expensive extra-costs owing to the ground heat exchangers (GHEs), whereas the air exploitation suffers lower temperatures and frosting conditions. Coupling both solutions in a dual-source heat pump system (DSHP) can mitigat...
Presentation
Full-text available
The presentation reports experimental results of a kit to transform standard small air-to-air heat pumps in dual-source heat pumps, able to thermally exploit the ground by mean of a closed loop coupled with Flat-Panels ground heat exchangers. The kit is called DSK, Dual-Souce Kit, and it's an idea explored during the HEGOS project, funded by Europe...
Conference Paper
Full-text available
Ground-coupled and air-source heat pumps (GCHPs and ASHPs, respectively) are regarded as energy efficient systems for air conditioning. Coupling both solutions in a dual air and ground source heat pump (DSHP) could offer a further performance improvement of heat pumps. The energy behaviour of a DSHP coupled with a Flat-Panel as a horizontal ground...
Conference Paper
Full-text available
The present paper analyses the preliminary results about the performance of a dual-source heat pump (DSHP), able to switch between air and ground according to operating rules for the airconditioning system. The prototype is composed by a common air-to-air heat pump whose refrigerant circuit has been modified for coupling through a plate heat exchan...
Article
Shallow ground heat exchangers are increasingly studied due to their advantages in cost and long-term energy performance stability when coupled with heat pumps for space heating and cooling. As for borehole heat ex-changers, the backfilling material affects significantly the operating efficiency of the whole system, mainly driven by the low thermal...
Article
Full-text available
This study investigates the thermal and fluid-dynamic behaviour of two ventilated roofs equipped with a new tile shape in comparison with a standard Portuguese tile. The novel tile shape was designed to improve the air permeability of coverings, thus producing a further above sheathing ventilation (ASV) enhancement as proposed in the ongoing LIFE H...
Article
In hot climates, ventilated pitched roofs with tiled coverings reduce the heat transfer across the roof, due to the ventilated air layer between tiles and roofing underlay, which is formed by the arrangement of battens and counter-battens. This so-called Above Sheathing Ventilation (ASV), which depends on the air entering and leaving at the eaves,...
Article
Full-text available
In tiled pitched roofs, a ventilated layer reduces the heat transfer between tiles and roof structure by means of natural and forced convection, thereby also reducing the cooling energy requirement. This effect could be enhanced by increasing the air permeability between the tiles by means of novel tile shapes, as proposed by the HEROTILE European...
Conference Paper
Full-text available
The thermal performance of a ventilated pitched roof with tiled coverings is analysed and compared with unventilated roofs. The analysis is carried out by means of a finite element numerical code, by solving both the fluid and thermal problems in steady-state. A whole one-floor building with a pitched roof is schematized as a 2D computational domai...
Article
Full-text available
In hot climates tiled pitched roofs significantly reduce the heat transfer across the roof structure, due to the ventilated air layer between tiles and roofing underlay formed by the arrangement of battens and counter-battens supporting the tiles. This so-called Above Sheathing Ventilation (ASV) depends on the air entering and leaving at the eaves,...
Conference Paper
Full-text available
The performance of horizontal ground heat exchangers (HGHEs) is strongly dependent on climatic conditions, due to the low installation depth. In numerical modelling of HGHEs, the estimation of shallow soil temperature distribution is a key issue, therefore the boundary condition (BC) at the ground surface should be assigned carefully. With this in...
Conference Paper
Full-text available
Heat pumps may be coupled to shallow-ground geothermal fields and used for the purpose of space heating and cooling of buildings. However, quite often it is not possible to locate the geothermal field in cleared grounds, especially in cities where building density is high and land has a high premium. This leads to the possibility of burying the geo...
Poster
Full-text available
In climates with high temperature and solar radiation, reducing the cooling consumption and increasing the standards of indoor comfort are topics of great importance. The roof plays a key role in controlling the indoor thermal comfort. In ventilated roofs, air flow within the ASV (Above Sheathing Ventilation) depends on the air entering and leaving...
Conference Paper
Full-text available
In ventilated roofs, the so-called Above Sheathing Ventilation (ASV) helps dissipating the excess heat in summer, thus reducing the cooling energy requirement. The ASV can be enhanced by increasing the air permeability of the tiled covering through the development of new tile shapes. This is the purpose of the Life HEROTILE European project, of whi...
Article
A dual air and ground source heat pump can be an effective solution to improve the performance of a heat pump, by reducing the respective drawbacks of each individual technology. A dual source system in fact, allows a reduction in the size of the ground heat exchanger. Moreover, a dual source system can achieve a higher efficiency by switching to t...
Article
This study first describes the principle of a lens-walled CPC (compound parabolic concentrator) which compromises the advantages of common mirror CPC and solid dielectric CPC, by applying a lens shape on the surface of a common CPC. Due to the structural feature of a CPC, the irradiation on the base of a CPC is non-uniform, where a PV cell is insta...
Article
The effect on numerical solution of different thermal boundary conditions at the ground surface was analysed in modelling HGHEs. Boundary conditions of the 1st, 2nd and 3rd kind have been alternately tested by means of a finite element numerical code, solving the unsteady-state heat transfer problem in a 2D domain. An energy balance equation at the...
Conference Paper
Full-text available
Integrating air and ground source can be an effective solution to improve the performance of a heat pump by reducing the drawbacks of each individual technology. In fact, a dual source system not only greatly reduce the size of the ground heat exchanger, but also can achieve a higher efficiency by selecting the more thermally favourable source. Hen...
Conference Paper
This study first describes the principle of a lens-walled CPC (compound parabolic concentrator) which compromises the advantages of common mirror CPC and solid dielectric CPC, by applying a lens shape on the surface of a common CPC. Due to the structural feature of a CPC, the irradiation on the base of a CPC is non-uniform, where a PV cell is insta...
Conference Paper
Full-text available
Geothermal energy is produced by coupling a heat pump with the ground, resorting to ground heat exchangers (GHEs) that can be installed in vertical or inclined boreholes or horizontally in shallow ground. Horizontal GHEs are easy to be installed and maintained, more compliant with environmental regulations, and generally do not interfere with groun...
Article
Full-text available
Efficient and sustainable exploitation of low-enthalpy geothermal energy relies on accurate representations of heat transfer processes in the subsurface. An analytical model, which provides such a representation by predicting the dynamics of thermal fields induced by shallow GHEs (ground heat exchangers), is derived. The model accounts for atmosphe...
Article
A discounted cash flow analysis (DCFA) and a cost-benefit analysis (CBA) have been implemented in order to investigate the economic aspects of ground-coupled heat pump (GCHP) for space heating and cooling, in comparison to traditional condensing boiler (CB). The DCFA allows the analysis of investment costs, operating costs and savings of the two di...
Conference Paper
Full-text available
The effect on numerical solution of different thermal boundary conditions at the ground surface was analysed in modelling HGHEs. Boundary conditions of the 1st, 2nd and 3rd kind have been alternately tested by means of a finite element numerical code, solving the unsteady-state heat transfer problem in a 2D domain. An energy balance equation at the...
Article
Full-text available
This study presents a numerical validation of a new approach to model single junction PV cell under non-uniform illumination for low-concentration solar collectors such as compound parabolic concentrators (CPC). The simulation is achieved by finite element modelling (FEM). To characterize the results, the model is simulated with five different non-...
Article
The use of a horizontal ground heat exchanger may represent a reliable and cost effective option for ground-source thermal applications. This study presents the thermal performance analysis of a drainage trench used as ground heat exchanger (GHE) coupled with underground thermal energy storage (UTES). The trench is dug in shallow soil and filled wi...
Article
The energy performance of a shallow ground heat exchanger constituted by a drainage trench is studied. The 12 × 2 × 0.5 m trench is dug in shallow soil and filled with gravel; two vertical tubes at the opposite ends of the trench act as inlet and outlet of the working fluid, which flows into the closed loop of a system for heating/cooling of a resi...
Article
Full-text available
Ground-source heat pumps are a reliable technology and may represent an efficient and cost-effective option for space heating and cooling, when the investment for ground heat exchangers is reasonable. New advanced ground exchangers have been recently proposed, showing high performances also in shallow ground; their shape has not yet been investigat...
Conference Paper
Full-text available
The paper presents a new tool for the thermal comfort evaluation in outdoor public spaces. The model (I-COOL), that is part of a larger doctoral research, defines a new index (VTC) for the evaluation of several components affecting the thermal comfort sensation. The VTC index is a synthesis of the two approaches described in literature (physiologic...
Article
Thermal energy storage with phase change materials (PCMs) is a functional strategy to minimize the sizing of air conditioning systems and reduce their primary energy consumption. This approach is well known in ground-coupled heat pump applications (GCHP), especially with use of borehole ground heat exchangers (GHEs). However, this is seldom investi...
Conference Paper
Unlike deep and vertical boreholes heat exchangers, shallow and horizontal ground heat exchangers (GHXs) exploit mainly the temporary underground thermal energy storage of the solar radiation. So, the soil surface finishing could play an important role for the energy balance and the performance of the GHXs. To evaluate the relevance, a numerical ap...
Conference Paper
Novel shapes of horizontal ground heat exchangers coupled with ground-source heat pumps represent a viable and efficient option for shallow geothermal plants. Here, the thermal performance of a drainage trench employed as a ground heat exchanger is studied. The 12 x 2 x 0.25 m trench is dug in shallow soil and filled with gravel; two tubes at the o...
Conference Paper
Ground-coupled heat pumps are a reliable technology for space heating and cooling. When coupled with horizontal ground heat exchangers, the profitability may increase according new advanced shapes may that show high performances. In the present study, the analytical method proposed by the Italian regulation UNI-11466 is applied for sizing a novel t...
Conference Paper
Full-text available
A discounted cash flow analysis (DCFA) and a cost benefit analysis (CBA) have been implemented in order to investigate the economic aspects of ground coupled heat pump (GCHP) for space heating and cooling, in comparison to traditional condensing boiler (CB). The DCFA allows the analysis of investment costs, operating costs and savings of the two di...
Conference Paper
Full-text available
Ground-source heat pumps (GSHPs) are a sustainable energy technology for space heating and cooling, obtained by coupling of heat pumps with the ground by means of vertical or horizontal ground heat exchangers (GHXs). The horizontal GHXs are commonly placed in shallow diggings few meters deep in soil, as opposed to the vertical deep solution where t...
Conference Paper
Full-text available
Employing Phase Change Materials (PCMs) is normally considered as an effective measure to store thermal energy, by means of their latent heat during phase changing. But, it could also represent a method to smooth the thermal wave generated from operations of thermal machines, such as ground-source heat pumps (GSHPs). This paper evaluates the applic...
Article
Full-text available
An experimental setup is devised to investigate the behaviour of a novel type of a horizontal ground heat exchanger (HGHE). The prototype is named ‘flat panel’ and is coupled with a hydraulic closed loop in which warm water is circulating to express the cooling mode from a reversible-cycle heat pump. Several thermal sensors are employed in the expe...
Conference Paper
Full-text available
An experimental plant has been devised to investigate the behaviour of a novel type of horizontal ground heat exchanger (GHX), aiming to improve the performance of ground-source heat pumps for space heating and cooling. The GHX system is composed by hollow flat panels, which have been installed edgeways in shallow trenches two meters deep in soil....
Conference Paper
Full-text available
In recent years the diffusion of distributed generation systems has undergone a considerable growth, driven by their increasing cost-effectiveness and by more stringent regulations on energetic efficiency of buildings. This paper jointly addresses two major issues, affecting two of the highest-market-potential microgeneration technologies: the high...
Article
Full-text available
Several solutions are currently being tested to improve the thermal efficiency of ground heat exchangers (GHEs) employed in geothermal closed loops. For shallow exchangers, the main effort is towards maximizing the surface available for heat exchange, while reducing the interference among exchangers; popular solutions towards this end are the slink...
Conference Paper
Full-text available
A DCF model (discounted cash flow model) is implemented in order to investigate the economic aspects of GSHP (ground source heat pump) for heating and cooling, in comparison to traditional CB (condensing boiler). The DCF model allows the analysis of investment costs, operating costs and revenues of the two different systems in order to understand i...
Article
A Discounted Cash Flow Model has been implemented in this paper in order to investigate the economic impact of groundsource heat pump for heating (GSHP) and cooling in comparison with traditional condensing boiler (CB). The economic model allows the analysis costs and revenues of the two different systems and seeks to provide if the GSHP outperform...
Conference Paper
Ground heat exchangers (GHEs) are rarely installed horizontally in linked ground source heat pumps used for space conditioning, because the horizontal installation energetic performance is lower than the vertical one. However, the horizontal installation holds several advantages: it is easy to carry out and upkeep, it is more compliant with environ...
Article
Coupling ground heat exchangers to heat pumps for heating and cooling grants significant energy savings compared to the air heat systems, due to the source higher thermal stability and its better thermophysic properties. A coupled system, consisting of an horizontal ground heat exchanger linked to an ideal heat pump for cooling, is examined here Th...