Small Fan Research Articles

Numerical study on airflow performance and mechanical characteristics of centrifugal fan

As small fans are widely used to dissipate the heat of the electronic components, a series of special requirements are put forward on the airflow performance and stress characteristics. In the present study, the computational fluid dynamics (CFD) method is adopted to study the airflow characteristics of a specific type of fan, including the fluid pressure distribution, flow velocity field and fluid streamline distribution. The stress characteristics of the fan blades are systematically analyzed based on the fluid-solid coupling and thermal-solid coupling methods. The results show that with the rotation speed of 1400 rpm, the airflow velocity in the air duct is unevenly distributed, and some eddy disturbances form and occur in the flow field. To improve the operating efficiency of the fan, appropriate optimization schemes should be adopted to reduce the intensity and range of the eddy influence. When the inlet temperature is 20 °C, the stress on the impeller is mainly caused by centrifugal force and thermal load. As the inlet temperature increases, the effect of the thermal load becomes increasing. While for the centrifugal force, its influence on the impeller gradually disappears and completely disappears when the temperature reaches 50 °C.

Measurements of the flow field around an axial fan with acoustic resonance in an upstream duct

For a small axial-flow fan installed in a duct, the effects of the acoustic resonance occurring in the duct on the flow field and aerodynamic characteristic were investigated. The measurements of the sound pressure level around the fan installed in two ducts with different widths showed that more intense acoustic resonance occurs for the narrower duct at the blade passing frequency for a specific rotational speed. Moreover, the static pressure coefficient of the fan was found to drop at the specific rotational speed where the intense acoustic resonance occurs (resonance condition). To clarify the effects of the acoustic resonance on the immediately downstream wake flow of the fan, velocity measurements were conducted by a hot-wire anemometer. As a result, the time average velocity became lowest at the resonance condition for the narrower duct. This is possibly because the circumferential velocity became low due to a decrease in pressure load causing the curvature of the flow by the fan blade. Moreover, the power of velocity fluctuations around the blade tip in the frequency range lower than the blade passing frequency became largest at the resonance condition, which indicates the intensification of disturbances in the tip leakage vortices. The decreased pressure load and increased turbulence lead to the deterioration of the fan pressure coefficient.

CFD-Based Visualization of Effects of Obstructions on P - Q Curves of a Small Axial Cooling Fan

CFD-Based Visualization of Effects of Obstructions on P - Q Curves of a Small Axial Cooling Fan

EFFECT OF FINE PARTICULATE MATTER EXPOSURE ON TRIGGERING DEPRESSIVE-LIKE RESPONSE AND TOTAL BODY WEIGHT IN C57BL/6J MICE

Objective: To study the effect of fine particulate matter exposure in instigating depressive-like response and total body weight changes in C57BL/6J mice.
 Study Design: Laboratory-based experimental study.
 Place and Duration of Study: Anatomy Department, Army Medical College, Rawalpindi, in collaboration with the Military Hospital, Rawalpindi and the National Institute of Health (NIH), Islamabad, from Jun to Sep 2020.
 Methodology: Thirty male and female C57BL/6 mice, 8 weeks of age, weighing 37 ± 2 gm were obtained from NIH, Islamabad. They were retained in separate cages in the animal house of NIH under standard laboratory conditions. The animals were divided into two groups, 15 mice in each group (8 males and 7 females) Group A was marked as control, received regular diet and water ad libitum. Group B (experimental group) received dynamic inhalation of 3 mg/m³ fine particles (soot) through air circulation for 6h/d for 12 weeks, in a plastic cabin measuring 2x2x2 feet fitted with two small fans for evenly distribution of PM. The initial and final weight of animals was recorded, and a tail suspension test was performed to assessdepression in form of immobility.
 Result: The experimental group after exposure to fine particulate matter showed decreased activity and behavioural deficits with p-value <0.001 and loss in total body weight as compared to the control group with a p-value <0.001.
 Conclusion: Fine particulate matter has a significant effect on behaviour and cognition. It also causes a decrease in the total body weight of animals due to stress and agitation.

Improving the performance of the air-cooling unit in the cooling system of a radar

The article discusses the issues of reducing the size of the cooling unit of the antenna of a radar station by improving the gas-dynamic processes occurring in the air-cooling unit. The results of the experimental studies of the gas flow in a plate-fin heat exchanger, being blown by one axial fan are presented. The feasibility of changing the number of axial fans for organizing a more uniform flow around the heat-exchange surfaces has been determined by calculation and theoretical methods. The calculation results are confirmed by experimental studies of the air flow in the segment of the heat exchanger, which is provided by a smaller fan.

Intensity-based and a lifetime-based PSP imaging method with enhanced sensitivity

A pressure-/temperature-sensitive paint (PSP/TSP) has been developed and used as a measurement tool for the two-dimensional distribution of pressure and temperature on aerodynamic surfaces. In recent years, although the concern with measuring a pressure difference of several Pa, such as countermeasures against the noise of small fans, has been growing, the resolution of current PSP measurements is limited to several 10 Pa, even with carefully conducted measurements. For highly accurate measurements, researches on the advanced coating films in PSP/TSP have eagerly been conducted to date. However, measurement resolution and accuracy deteriorate when quantum efficiency or lifetime decrease under high pressure or high temperature conditions.

U-PB ages and environmental evolution of the De La Cuesta Formation (late Paleozoic): Record of the Choiyoi Volcanism in the retroarc area of the Paganzo Basin, Western Gondwana

This paper examines the relationship between the sedimentation in the retroarc Paganzo Basin and the activity of the magmatic arc developed in the neighboring Andean Cordillera during the Late Pennsylvanian-Cisuralian. The temporal relationships between the Choiyoi Volcanism (Andean region) and the retroarc Paganzo Basin were investigated according to three lines of research: 1. Sedimentology and lithostratigraphy of the De La Cuesta Formation, 2. Geochronology and, 3. Biostratigraphy.Paleoenvironmental studies indicate that small alluvial fans (facies association A) and braided river (facies association B) deposits prevailed in the lower third of the De La Cuesta Formation, which includes a thin intercalation of shallow marine sediments only present in the western part of the area (facies association C). A progressive decrease in the energy of the fluvial systems occurred at the middle part of the unit, where dominant finning-upward successions correspond to meandering rivers (facies association D). In contrast, interbedded sandstones and mudstones were subsequently deposited by low-energy ephemeral rivers (facies association E). Finally, the upper third of the De La Cuesta Formation corresponds to eolian sandstones (facies association F) and shallow water bodies deposits, including evaporites, limestones, and tuffs (facies association G) sedimented under semiarid to arid conditions with periods of explosive volcanism.A U–Pb age of 278.84 Ma was obtained from a tuff level at the uppermost part of the De La Cuesta Formation (facies association G). This age, together with one previously obtained of 311.89 ± 0.21 Ma corresponding to the base of the unit, indicate that the De La Cuesta Formation is Moscovian-Kungurian in age and that it was mostly deposited before the main phase of the Choiyoi magmatism, synchronically with the so-called Pre-Choiyoi magmatism. Furthermore, a rich palynological assemblage belonging to the Lueckisporites/Weylandites Biozone (LW), recovered from deposits of the facies association G, is equivalent to the Lueckisporites virkkiae (Lv) Biozone from the Paraná Basin (Brazil), pointing out a Kungurian age for these biostratigraphic units.The new radiometric age and the palynological taxa recovered from the top of the De La Cuesta Formation (facies association G) confirm a Kungurian age for this interval, establishing a key level for correlation between the sedimentation in the retroarc with the onset of the Choiyoi Volcanism in the magmatic arc.

Morphometry and morphology of fan-shaped landforms in the high-Arctic settings of central Spitsbergen, Svalbard

In this study, the distribution, morphometry and morphology of alluvial fans and colluvial cones were investigated in a high-Arctic, periglacial environment. The main aims were to present their surface morphology types, analyse the relationship between the morphometric properties of fans and their catchments, and to investigate potential factors controlling the morphometry of fans. Data from a set of 297 fan-shaped landforms in central Spitsbergen, Svalbard, were presented and analysed to ascertain factors likely to influence their distribution and character. First, based on the dominant morphological processes, the studied landforms were divided into three groups: fluvial-flow-dominated fans, debris-flow-dominated fans, and colluvial fans. Then, to analyse the relationship between fans and their catchments, 20 variables were investigated. Those analyses indicate that small catchments, characterised by a low relief and high Melton's R number, tend to produce small and steep fans. This tendency was most visible for colluvial fans and debris-flow-dominated fans but less so for fluvial-flow-dominated fans. The latter tend to adjust stronger to the local topography. However, in all cases, these associations were weaker than in morphometry studies based on data from other climatic settings. The most important controls on the distribution of the studied fan-shaped landforms seem to be the availability of accommodation space (related to deglaciation time) and local erosion base level.

Linear Drive Based on Silicon/Ethanol Composite.

The paper presents a concept of an actuator, based on a silicon/ethanol composite placed in the brass bellows. Such actuator is operating based on a change in the physical state of ethanol, which is enclosed in bubbles surrounded by a matrix of silicone rubber. In this paper, the prototype of the actuator is described, and a series of its test results, in the open and closed loops, are presented. Two laser distance-sensors, with different accuracies, were used as a source of the feedback signal. During the investigations the temperature of the actuator was also measured. This has allowed us to determine the delay in heat flow from the heater to the composite. In the closed loop, P- and PI-type controllers were used in the drive positioning experiments. It was discovered that in the closed loop control, it was possible to achieve a positioning error of less than 200 µm. During the tests, the temperature inside the drive and the ambient temperature were also measured. In order to improve the dynamics of the drive, a small fan was used, controlled by the automation system. It allowed us to shorten the time to return the drive to its starting position. The results of frequency tests of the drive have also been presented.

Reduced order model analysis to identify possible aerodynamic noise sources of small axial fan: POD and CNN

This paper reports computational analysis of location and strength of sound source of the noise generated by a small axial fan widely used as an air-cooling system. High-fidelity Navier-Stokes simulations with high-resolution compact scheme are conducted with an implicit Large Eddy Simulation (LES) method on a HPC system and the resultant large-scale data confirms existence of unsteady vortex structures and their interactions around the impellers, boss and casing of the fan. To identify location and strength of the sound sources, reduced order model analysis is conducted for the distribution of pressure fluctuations in space and time. Snapshot POD (Proper Orthogonal Decomposition) analysis both in time and in circumferential direction, together with conventional FFT analysis, identifies location and strength of the sound sources. In addition, Convolutional Neural Network (CNN) is attempted, which shows more physical mode decomposition and separates some of the important features shown in the snapshot POD analysis. The study shows that the two data-mining techniques considered here identify possible aerodynamic noise sources of the axial fan clearly in comparison to those in the previous studies.

Optimization of Low Noise Blade of Small Axial Fan at Low Reynolds Number

A multidisciplinary optimization design to simultaneously enhance the aeroacoustic and aerodynamic performance of an cooling fan is performed. The flow analysis of the cooling fan is conducted by solving three dimensional steady-state RANS equations with shear-stress transport turbulence model. Based on the results of the steady flow, aeroacoustic analysis is performed by using the Hanson and Brooks model. A multi-objective optimization is performed to simultaneously improve the efficiency and reduce the sound pressure level through an improved non-dominated sorting gentic algorithm. A Kriging surrogate model is used to approximate the function value while reducing computational cost. Series of optimum designs on the pareto front yielded increases in efficiency and decreases in the sound pressure level compared to the reference design. Through numerical analysis and experimental test, the aerodynamic efficiency is increased by 5% and the total sound pressure level is reduced by 4dB without loss of air volume for the selected optimized cooling fan. The thining of rotor boundary layer and inward load shift are the main factors to improve aerodynamic efficiency and reduce noise of the cooling fan.

Construction of Zn–Co–Ni–Se nanosheet arrays on nickel foam for hybrid supercapacitors

The polymetallic selenides exhibit rich redox reactions and high conductivity, making them promising electroactive materials for hybrid supercapacitors (HSCs). Herein, a two-step hydrothermal strategy was developed to grow ternary metal selenides (Zn–Co–Ni–Se) nanosheet arrays on Ni foam (NF) for HSCs. The Zn–Co–Ni–Se nanosheets uniformly covered on NF are favorable to boosting the energy storage activity because they can afford abundant pores, which is beneficial to increase the contact areas and promote ion transport. The binder-free feature can further improve the rate and cyclic performance. As an innovative binder-free electrode, the Zn–Co–Ni–Se NA@NF can deliver 2.5 C cm–2 at 3.1 mA cm–2. Strikingly, the Zn–Co–Ni–Se NA@NF//AC HSC can afford 0.13 mWh cm–2 at 1.27 mW cm–2. The capacity retention of Zn–Co–Ni–Se NA@NF//AC HSC is 92.9% after 5000 cycles at 6.4 mA cm–2. A Zn–Co–Ni–Se NA@NF//AC HSC device could successfully drive a small fan for about 150 s, displaying the bright application prospect of Zn–Co–Ni–Se@NF. Therefore, the present work demonstrates that Zn–Co–Ni–Se NA@NF is an excellent electroactive material for HSCs.

Tectonic–sedimentary interplay of a confined deepwater system in a foreland basin setting: the Pennsylvanian lower Atoka Formation, Ouachita Mountains, U.S.A.

ABSTRACT Submarine fans deposited in structurally complex settings record important information on basin evolution and tectonic–sedimentary relationships but are often poorly preserved in outcrops due to syndepositional and post depositional deformation. This study aims to understand the influence of tectonics on the deposition of the synorogenic Pennsylvanian lower Atoka submarine fan system deposited in a structurally complex foreland basin during the Ouachita orogeny. This study is a synthesis of new outcrop stratigraphic data as well as published stratigraphic and structural data. The lower Atoka crops out in the Ouachita Mountains and the southern Arkoma Basin and is divided into three structural–depositional zones: the foredeep, the wedge top, and the continental foreland. The mean paleoflow is axial, and each zone exhibits unique patterns in facies distribution. The foredeep consists of two fan systems, a large westward-prograding fan that exhibits significant longitudinal and lateral facies changes, and a small eastward-prograding fan on the western part. The wedge top consists of a westward-prograding fan that exhibits subtle longitudinal facies change. The continental foreland consists of small slope fan systems along the northern and western margins. By comparing to basin morphology and structural styles, we interpret the facies distribution patterns in the three zones as the result of different combinations of lateral structural confinement, axial and lateral sediment supply, and paleogeography. This study provides an improved and comprehensive understanding of the lower Atoka deepwater system and has implications for deciphering the tectonic–sedimentary relationships in laterally confined submarine fan systems.

High Resolution 2.5D PIV Measurements of the Flow Fields Generated by Small Fans

Abstract The free jets of an axial and a centrifugal fan have been scanned by a specialized particle image velocimetry (PIV) set-up, which allows for volumetric scans of the time-averaged velocity field. Both of these fans have similar dimensions of approximately 70 mm x 70 mm x 25 mm. A classic PIV set-up was combined with a precise linear stage to move the fans through the laser fan beam in small steps, creating a dense array of measurement planes. Two components of the time-averaged velocity field are captured by the first 2.5D scan. Another scan, with the fan rotated by 90° about its outlet surface normal, captures the missing third velocity component. This article describes the details of the measurement set-up, and mentions measures concerning seeding, reflections, and calibration. In the signal processing stage, two independent sets of gathered image data have to be processed, producing two sets of velocity image frames. These are subsequently combined using gridded interpolation in order to obtain a 3D velocity field. Specifically devised software tools allow for a CFD-like analysis and visualization of the flow field. Typical parameters of the generated jets, like the spreading and rotation rates, are calculated from the measurement data and details of the outlet flow fields are investigated. The interpolated data are also used to analyze the influence of an assumed coarser measurement grid resolution on the results for the obtained outlet flow fields.

Particle image velocimetry and constant temperature anemometer measurements of the jet produced by a centrifugal fan

This article presents a detailed investigation of the three-dimensional flow field produced by a small centrifugal fan used for cooling of electronic components, for instance, in the automotive industry. A particle image velocimetry (PIV) system captured numerous cross sections of the fan jet for analysis of velocity distribution and jet development. General parameters, such as the spreading rate, and flow specifics, such as the full width at half maximum contours in planes parallel to the fan outlet and the jet's rotation rate, were thus evaluated. In addition, constant temperature anemometry enabled a thorough investigation of the flow field at the fan's outflow port. Hot-wire measurements complement the PIV results by providing the power spectral density of the turbulent kinetic energy at several locations. Our results demonstrate that the cross-flow profile at the fan outlet consists of two counter-rotating vortices. This leads to a jet with a nearly elliptical, rotating cross section, which does not propagate in a direction perpendicular to the outlet plane. Several aspects of these distinctive flow features are evaluated and presented to provide both fluid mechanics and heat transfer engineers with (i) data on the air jet produced by a small centrifugal fan and (ii) reference data for computational fluid dynamics simulations. Despite complex flow development in the near field of the jet and the nonaxisymmetric jet contour in the intermediate field, our results are in good agreement with published data on axisymmetric jets in terms of spreading rate and the development of turbulence spectra observed in the intermediate field.

Experimental and numerical studies on small contra-rotating electrical ducted fan engines

Electrical propulsion has been identified as one of the key fields of future research within the aerospace sector. The Institute of Aeronautical Engineering at the Universität der Bundeswehr München aims to contribute to the ongoing development of small-sized electrical ducted fan engines with a thrust in the range of 100 N. A special emphasis is placed on electrically powered contra-rotating fan stages. When compared to a conventional rotor–stator stage, contra-rotating fan stages allow for a more compact design, considering a given pressure ratio, or an increased pressure ratio at a constant fan diameter. Since numerous new aircraft concepts are presently being developed, a high demand for compact and powerful electrically driven engines arises. Electrically driven contra-rotating fan engines provide a high potential in terms of compactness, emissions and efficiency. Using electric motors offers the ability to overcome common issues, such as design and integration of a contra-rotating stage into a gas turbine. An innovative new engine design featuring such a contra-rotating stage is developed and tested at one of the Institute’s test benches for electrical propulsion. Key components are two brushless motors powering the fan stage, one for each rotor. Various operation points are investigated experimentally during an extensive test campaign. Experimental results are compared to results of numerical simulations computed by ANSYS CFX. Results indicate a good agreement between experiment and simulation. The engine is running very smooth throughout all tested operation points. Yet, intensive heating up of the electric motors and high-temperature zone are found to be an issue at higher rotation speeds.

Evaluation of TiO2 Based Photocatalytic Treatment of Odor and Gaseous Emissions from Swine Manure with UV-A and UV-C.

Simple SummaryPoor indoor air quality and gaseous emissions are undesirable side effects of livestock and poultry production. Gaseous emissions of odor, odorous volatile organic compounds (VOCs), ammonia (NH3), hydrogen sulfide (H2S), and greenhouse gases (GHGs) have detrimental effects on the quality of life in rural communities, the environment, and climate. Proven mitigation technologies are needed to increase the sustainability of animal agriculture. This study’s objective was to evaluate the ultraviolet (UV) light treatment of odor and common air pollutant emissions from stored swine manure on a pilot-scale. To our knowledge, this is the first study of this scope that was needed for scaling up technologies treating gaseous emissions of odor, odorous VOCs, NH3, H2S, ozone, and GHGs. The study bridged the knowledge gap between lab-scales and simplified treatment of model gases to the treatment of complex gaseous mixtures emitted from swine manure in fast-moving air. The manure emissions were treated in fast-moving air using a mobile lab equipped with UV-A and UV-C lights and photocatalytic surface coating. The percent reduction of targeted gases depended on the UV dose and wavelength. While generally mitigating targeted gases, some UV treatments resulted in CO2 and ozone (O3). The results proved that the UV technology was sufficiently effective in treating odorous gases, and the mobile lab was ready for farm-scale trials. The UV technology can be considered for the scaled-up treatment of emissions and air quality improvement inside livestock barns.It is essential to mitigate gaseous emissions that result from poultry and livestock production to increase industry sustainability. Odorous volatile organic compounds (VOCs), ammonia (NH3), hydrogen sulfide (H2S), and greenhouse gases (GHGs) have detrimental effects on the quality of life in rural communities, the environment, and climate. This study’s objective was to evaluate the photocatalytic UV treatment of gaseous emissions of odor, odorous VOCs, NH3, and other gases (GHGs, O3—sometimes considered as by-products of UV treatment) from stored swine manure on a pilot-scale. The manure emissions were treated in fast-moving air using a mobile lab equipped with UV-A and UV-C lights and TiO2-based photocatalyst. Treated gas airflow (0.25–0.76 m3∙s−1) simulates output from a small ventilation fan in a barn. Through controlling the light intensity and airflow, UV dose was tested for techno-economic analyses. The treatment effectiveness depended on the UV dose and wavelength. Under UV-A (367 nm) photocatalysis, the percent reduction of targeted gases was up to (i) 63% of odor, (ii) 51%, 51%, 53%, 67%, and 32% of acetic acid, propanoic acid, butanoic acid, p-cresol, and indole, respectively, (iii) 14% of nitrous oxide (N2O), (iv) 100% of O3, and 26% generation of CO2. Under UV-C (185 + 254 nm) photocatalysis, the percent reductions of target gases were up to (i) 54% and 47% for p-cresol and indole, respectively, (ii) 25% of N2O, (iii) 71% of CH4, and 46% and 139% generation of CO2 and O3, respectively. The results proved that the UV technology was sufficiently effective in treating odorous gases, and the mobile lab was ready for farm-scale trials. The UV technology can be considered for the scaled-up treatment of emissions and air quality improvement inside livestock barns. Results from this study are needed to inform the experimental design for future on-farm research with UV-A and UV-C.

Early post-rift confined turbidite systems in a supra-detachment basin: Implications for the early to middle Miocene basin evolution and hydrocarbon exploration of the Pannonian Basin

Understanding the interplay of sedimentation and deformation style is essential to develop an adequate model of the evolutionary history of an extensional sedimentary basin. Due to their volume and temporal extent, late post-rift deposits are often in the focus of research; however, early post-rift deposits are less studied. The aim of the study is to reconstruct the tectono-sedimentary evolution of a syn -rift to early post-rift succession in the hanging wall of a low-angle detachment zone and to recognize the effects of this deformation style on turbidity current pathways and depocenters. The small Őri sub-basin of the western part of the Miocene Pannonian basin is used as a study area where the oldest early post-rift turbidites of ~15–12.8 Ma occurred. These sediments were deposited in a supradetachment setting, where inherited and actively forming structures controlled the sediment pathways and accommodation of both the distally and locally sourced marine turbidites. Seismic data, well logs and core information were integrated to identify and analyze unconformities, structural elements, and turbidite deposits. Syn-rift, early post-rift and late post-rift system tracts were identified. The syn -rift/post-rift unconformity is a result of combined eustatic sea level drop and the change in deformation intensity. The main low-angle detachment fault, orthogonal hanging wall transfer faults and related folds together controlled the complex synformal shape of the basin, which was related to major corrugations of the footwall detachment. Four turbidite phases were distinguished based on upward increasing sand content, areal extent, reservoir quality, and degree of confinement as the turbidity currents reached the basin margins. (1) Small fans deflected by transfer faults developed, followed by (2) an axial turbidite system that reached an anticline and was deflected by it. (3) Lateral confinement by the anticline increased significantly and thick sandstone bodies with abrupt pinch-outs formed, while the influence of smaller faults diminished. (4) The axial turbidite systems covered the basin floor and their interaction with basin margins created continuous sand bodies of confined character. The sand fairways and types of confinement of a supra-detachment basin differ from high-angle normal fault systems. The exhumed metamorphic rocks provided the sediment, and the extension-parallel antiformal and synformal corrugations acted as lateral confinement. The gentle back-tilt of the detachment hanging wall block exerted a frontal confinement for the extensive turbidite system at the distal part of the basin, but the gentle NE-ward dip over the detachment still permitted long run-out distances. • Combination of eustasy and tectonics leads to syn-rift-early post-rift unconformity. • Corrugation fold of a detachment creates an intricate topography for sediment flows. • Deformation activity decreases during deposition of early post-rift turbidites. • Lateral, frontal confinement of turbidity currents controls reservoirs quality. • Differences between sand fairways in high- and low-angle extensional systems.

Analyzing Interaction Noise from a Small Contra-Rotating Fan Enclosed with Lined and Unlined Casings

AbstractThe interaction noise that radiates from ducted contra-rotating (CR) fans are theoretically characterized using Green’s analytical functions for lined and unlined circular ducts containing ...

Study of novel solar assisted heating system

The potential for energy, carbon dioxide equivalent (CO2e) and cost savings when using low emissivity (low-ε) transpired solar collectors (TSCs), combined with heat pumps in a range of configurations, has been investigated using computer modelling. Low-ε TSCs consist of metal solar collector plates with a spectrally sensitive surface, perforated with holes. Ambient air is drawn through the holes and heated by convection from the solar collector plate, increasing the air temperature by up to 25 K. The heated air can be used for e.g. space heating, or pre-heating water in buildings. The models developed have been used to compare the performance of low-ε TSC/heat pump heating systems in small and large buildings, at a range of locations. The model results showed savings in energy, CO2e and costs of up to 16.4% when using low-ε TSCs combined with an exhaust air heat pump compared with using the exhaust air heat pump alone. Practical application: If the UK is to meet its target of reaching net zero greenhouse gas emissions by 2050, it will be necessary to adopt low or zero carbon heating technologies. The novel low emissivity transpired solar collector device investigated can contribute to this. Its advantages include: (i) utilising solar radiation; (ii) readily integrated with existing heating systems e.g. heat pumps; (iii) significant energy, CO2e emissions and cost savings; (iv) low cost device; (v) minimal energy input i.e. one small fan; (vi) can be retrofitted to existing buildings; (vii) its benefits were applicable at all of the (wide range of) locations tested.