THE IMPACT OF ENERGY & SUSTAINABILITY IN BUILDINGS

The impact of Energy & Sustainability in Buildings



Abstract

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 figures between 20% and 40% in developed countries, and has exceeded the other major sectors: industrial and transportation. Growth in population, increasing demand for building services and comfort levels, together with the rise in time spent inside buildings, assure the upward trend in energy demand will continue in the future. For this reason, energy efficiency in buildings is today a prime objective for energy policy at regional, national and international levels. Among building services, the growth in HVAC systems energy use is particularly significant (50% of building consumption and 20% of total consumption in the UK). This paper analyses available information concerning energy consumption in buildings, and particularly related to HVAC systems. Many questions arise: Is the necessary information available? Which are the main building types? What end uses should be considered in the breakdown? Comparisons between different countries are presented specially for commercial buildings. The case of offices is analysed in deeper detail.

Table of contents

Abstract2

Chapter 1: Introduction5

Chapter 2: Literature Review9

Energy consumption in buildings11

Heating, ventilation and air conditioning (HVAC)15

Non-domestic buildings17

Energy analysis29

Transmission heat losses of the envelope30

Ventilation heat losses31

Solar heat gains through windows31

Internal heat gains32

Specific lighting power/lighting power33

Resulting heat demand33

Envelope subsystem37

Room air subsystem37

Emission subsystem38

Distribution subsystem38

Storage subsystem39

Generation subsystem39

Primary energy transformation subsystem40

Total exergy system efficiency41

Energy/ Exergy42

Chapter 3: Methodology45

Research in performance evaluation methodologies50

Chapter 4: Discussion55

Investment considerations and evaluation techniques for intelligent building56

Net present value method58

Life cycle costing analysis59

Cost benefit analysis60

Analytical hierarchy process63

Chapter 5: Conclusion66

References67

Appendix A72

System selections and input parameters of the heating chain72

The impact of Energy & Sustainability in Buildings

Chapter 1: Introduction

The European Union (EU) Member States are working intensively to improve energy efficiency in all end-use sectors and to increase the exploitation of renewable energy sources (RES) in order to tackle environmental concerns deriving from energy consumption of fossil fuels, and to support self-sufficiency and energy security. Energy efficiency is expected to play a key role in meeting the EU target in accordance to the Kyoto commitments to reduce CO2 emissions in an economic way.

In 2002, the gross inland consumption in the EU-27 member states was 1677 Mtoe . The final energy consumption reached 1080 Mtoe, of which 44% oil, 23.9% gas, 20.2% electricity, 4.8% solid fuels, 4.2% renewables and 2.8% derived heat. This is a grim situation given that the EU-27 import dependency is 48% for all fuels, and 76.8% for oil, 51.3% for gas and 33.2% for solid fuels. The European Commission estimates that the import dependency will reach two-thirds by 2020, with increased risks for the energy security of supply, unless some urgent additional measures and policies are adopted. Buildings are also a major pollution source. The most important greenhouse gas (GHG) by far is carbon dioxide (CO2), accounting for 82% ...