Luis Pérez-Lombard

Universidad de Sevilla | US · Energy Engineering

The improvement of energy efficiency of products is a key pillar of climate and energy strategy in the European Union (EU). The first EU product policies were adopted in the late 1970s, and they have evolved to become a coherent set of implementing measures under framework directives that harmonise and refine the regulatory process. After years of...

Water evaporation rate is among the most significant parameters to design and select air conditioning systems in buildings with indoor swimming pools. Experimental correlations are today widely used to estimate water evaporation rate, although discrepancies of up to 80% among existing correlations have been shown. An alternative to these empirical...

Buildings are a major contributor to climate change, accounting for one third of global energy consumption and one quarter of CO2 emissions. However, comprehensive information is lacking for the development, evaluation and monitoring of mitigation policies. This paper discusses the remaining challenges in terms of reliability and consistency of the...

The residential sector is a major contributor to climate change, accounting for almost a quarter of global energy consumption and a fifth of CO2 emissions in 2019. Since 2000, residential consumption has grown at a sustained rate of 1%/year, driven by the development of emerging economies, despite stagnation in developed countries. The increasing d...

The impact of energy use on the planet due to related CO2 emissions is continuously increasing, despite the adoption of efficiency and decarbonisation policies and widespread environmental awareness. Climate change mitigation will only succeed if the driving forces of consumption and emissions are deeply analysed, and effective means are provided t...

Energy efficiency remains as the main mitigation factor to slow down the growth of energy consumption and related CO2 emissions, undoubtedly the major responsible for climate change. Gaining insights into the driving forces that make efficiency change is a keystone to define energy policies and examine pathways to sustainable development. To this a...

This paper presents a new hybrid two-dimensional model to simulate single U-tube ground heat exchangers based on the use of the electrical analogy to model heat transfer within the borehole and thermal response factors (short and long time-step g-functions) to estimate heat flow to the surrounding ground. Unlike other similar models, heat transfer...

This paper proposes a practical solution to the problems arising when the conduction transfer function (CTF) method is applied to solve the 1D transient component of heat transfer in the internal zone of ground-coupled floors. The lower boundary condition for these problems must be imposed at a depth of several metres. The proposed method is based...

The calculation of the shadows that building environment, building elements or shading devices may cast on the building envelope, plays a key role in load calculations and building energy simulation. Algorithms for solar shading calculations have direct repercussions on the accuracy of the results and the computational times of building simulation...

Despite the industrial sector accounts for about a quarter of total final consumption worldwide and great efforts have been carried out to reduce its energy use in the last decades, there are still substantial opportunities to improve industrial energy efficiency. Among those opportunities, energy management systems (EMSs) are one of the most succe...

In a naphtha distillation process, the natural objective is to perform an entire process maximization of the production rate while meeting required product qualities by searching for an optimal operating condition by manipulating the operating variables. The objective of this paper includes performing an energy process optimization. Not only is an...

The energy efficiency of industrial plants is an important issue in any type of business but particularly in the chemical industry. Not only is it important in order to reduce costs, but also it is necessary even more as a means of reducing the amount of fuel that gets wasted, thereby improving productivity, ensuring better product quality, and gen...

Energy efficiency is a central target for energy policy and a keystone to mitigate climate change and to achieve a sustainable development. Although great efforts have been carried out during the last four decades to investigate the issue, focusing into measuring energy efficiency, understanding its trends and impacts on energy consumption and to d...

Energy efficiency is a central target for energy policy and a keystone for sustainable development. However, the lack of a valid set of energy efficiency indicators (EEI) sufficiently accurate, robust and repeatable is significantly affecting the success of such policies and causing no little confusion and speculation on this field. Therefore, it a...

Heating, ventilation and air conditioning (HVAC) systems are the most energy consuming building services representing approximately half of the final energy use in the building sector and between one tenth and one fifth of the energy consumption in developed countries. Despite their significant energy use, there is a lack of a consistent and homoge...

Building energy regulations, also referred to as building energy codes, emerged in the 1970s as an essential tool for improving energy efficiency and minimising energy consumption in buildings. Basically they aim at setting minimum energy efficiency requirements to achieve energy efficient design in new buildings. This paper analyses the developmen...

The distillation process accounts more than 25% of total process energy consumption in refineries. Therefore the energy improvements of the distillations units are very important for this sector. Six Sigma is a methodology supported by a handful of powerful statistical tools in order to reduce variation through continuous process improvement. This...

Enhancing load calculation tools into building simulation programs requires an in-depth revision and fine tuning of the load calculation assumptions prior to the addition of the HVAC system modelling routines. It is of special interest the analysis of transient heat conduction through multi-layer walls where, in order to improve the coupling betwee...

Energy certification schemes for buildings emerged in the early 1990s as an essential method for improving energy efficiency, minimising energy consumption and enabling greater transparency with regards to the use of energy in buildings. However, from the beginning their definition and implementation process were diffuse and, occasionally, have con...

The rapidly growing world energy use has already raised concerns over supply difficulties, exhaustion of energy resources and heavy environmental impacts (ozone layer depletion, global warming, climate change, etc.). The global contribution from buildings towards energy consumption, both residential and commercial, has steadily increased reaching f...

EECCAC is an EU funded project, where twelve participants (National Energy Agencies, Manufacturers, University laboratories and Electric utilities) from eight countries gathered to identify the most suitable measures to achieve market transformation in the direction of energy efficiency of central air conditioning systems in Europe. Its basement wa...

Save study named "Energy Efficiency and Certification of Central Air Conditioners" for the DG TREN regarding central air conditioners. Contains the basis of the Eurovent ESEER and proposed measures to limit the consumption and CO2 emissions of air conditioning.

EECCAC is an EU funded project, where twelve participants (National Energy Agencies, Manufacturers, University laboratories and Electric utilities) from eight countries gathered to identify the most suitable measures to achieve market transformation in the direction of energy efficiency of central air conditioning systems in Europe. Within the proj...