CHEMICAL ENGINEERING TRANSACTIONS  
 

VOL. 61, 2017 

A publication of 

 

The Italian Association 
of Chemical Engineering 
Online at www.aidic.it/cet 

Guest Editors: Petar S Varbanov, Rongxin Su, Hon Loong Lam, Xia Liu, Jiří J Klemeš 
Copyright © 2017, AIDIC Servizi S.r.l. 

ISBN 978-88-95608-51-8; ISSN 2283-9216 

A Complex Approach to the Energy Efficiency of Buildings 

and Processes in Industrial and Municipal Areas 

Vítězslav Máša*, Petr Stehlík, Martin Havlásek 

Institute of Process Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technická 2, 616 69 

Brno, Czech Republic  

masa@fme.vutbr.cz 

This contribution discusses the energy efficiency of buildings and processes in industrial and municipal areas. 

Standard procedures in energy management have proved insufficient for many industrial facilities and the 

benefits of implemented energy saving measures are rather limited. There is a lack of procedures for identifying 

and implementing optimal saving measures in commercial and mid-size industrial facilities, with input from 

dozens of kW to units of MW. Effective procedure must be valid for a wide rangeof energy systems whilst 

keeping its practical applicability. Such procedures are difficult to find in the literature. This article provides a 

complex approach to energy saving projects and thus contributes to closing the existing gap. The complex 

approach targets three levels: (1) the technological level: all buildings and processes involved in the production 

and consumption of energy, (2) the time level: in respect to the dynamic behaviour of the systems, and (3) the 

methodological level: a systematic approach from the initial analysis of the system to the design of the energy 

saving measures. 

The article stresses the analytical phase of the project, which deals with acquiring qualified data. Reliable 

experimental and operational data lead to the use of mathematical models that increase the quality of the final 

results. The complex approach was applied on various case studies. Its implementation creates new, efficient 

way to conduct research projects on energy savings.  

1. Introduction 

Mid-size industrial facilities and municipal buildings usually utilize energy systems that consume power and/or 

thermal power ranging from dozens of kW to units of MW. These energy systems are usually local boilers and 

boiler houses in close vicinity to the place of consumption. Heat from central heating systems can be an 

alternative. External contractor provides power supply or the supply may come from in-house power production. 

There is a big potential to decrease the primary energy sources consumption (Backlund et al., 2012). Real-time 

evaluation of energy intensity, wide use of mathematical modeling and detailed consumption analysis are among 

the current trends of increasing the energy efficiency (Zhou et al., 2016). More complex and detailed analyses 

of facilities' energy intensity have a positive impact on accuracy of the developed mathematical models but they 

are rather time consuming. Owners of energy systems face a difficult task of selecting and implementing a 

concrete saving measure. Figure 1 shows typical energy saving measures used in commercial and mid-size 

industrial facilities as well as in municipal areas. These measures are commonly combined to maximize the 

effects of a particular energy system (Sorrell, 2015).  

Owners of the energy systems, buildings and various industrial processes are generally aware of the fact that 

increase in energy efficiency has a potential for their business. However, they often postpone application of the 

changes, which may have the following causes:  

• Lack of knowledge of available solutions and lack of trust in real benefits of the saving measures 

• Conservative approach to application of results of R&D compared to “tested solutions” 

• Fear of a negative impact that the changes may have on reliability of their facilities   

• Energy cost is part of the overhead; overhead is only a small percent of the total operating cost  

• Lack of investments 

                               
 
 

 

 
   

                                                  
DOI: 10.3303/CET1761178

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Please cite this article as: Máša V., Stehlík P., Havlásek M., 2017, A complex approach to the energy efficiency of buildings and processes in 
industrial and municipal areas, Chemical Engineering Transactions, 61, 1081-1086  DOI:10.3303/CET1761178  

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mailto:masa@fme.vutbr.cz


All of these leads only to partial solutions to energy efficiency. There have been various tools and methods 

developed in recent years which should make it easier to selectg a saving measure. The so far published 

methods may be beneficial in the initial part of the project which aims to define current state of the energy 

system. However, the methods present no procedures for identification or implementation of suitable saving 

measures; if any procedures are discussed, they concern very specific case studies (Krones and Müller, 2014). 

Most of the methods focus on the building sector (Sesana et al., 2016). The only method describing a concrete 

procedure for industrial facilities was published by Smith and Ball (2012) and concerns production processes. 

The literary search has proved that there is a lack of practical procedures how to increase energy efficiency in 

day-to-day operations of various facilities. This gap may be filled by the complex approach which is presented 

in the following chapters.  

 

 

Figure 1: Overview of the usual energy saving measures for the commercial and mid-size industrial facilities 

2. Current state of energy management in practice 

The most used practical methods for energy savings are the energy management (EM) and energy performance 

contracting (EPC). EM is a general tool that enables to effectively manage and reduce energy consumption. 

Benefits of EM for energy savings are substantiated by various scientific papers (Lee and Cheng, 2016). The 

savings may be attributed to the fact that the facilities' owners, for the first time, have begun to take into 

consideration the energy efficiency of their businesses. EM systems do not provide specific saving measures 

that would best suit a particular energy system. Implementation of an EM system usually does not require any 

special investments; however, rigorous application of the system is an organizational and management 

challenge, as documented in many scientific papers discussing EM in industrial facilities. Though the papers 

mostly present case studies describing concrete saving measures, the benefits of the measures are not 

evaluated or only on a short-term level (Schulze et al., 2016).  

The other method for energy consumption decrease is EPC. The EPC is a very effective method that helps 

decrease the operating costs; it has been around since the 1970s and has stood the test of time. At the core of 

the EPC method is a mechanism that finances saving measures and helps refurbish the energy system, thusly 

decreasing the energy consumption very quickly. The EPC focuses mainly on economic benefits of the 

implemented measures. The savings should cover the initial investments and provide profit for both contracting 

parties. The contractor (Energy Service Company, ESCo) is responsible for the planned savings.  

If the ESCo fails to achieve the guaranteed savings, they must compensate the facility owner for the financial 

loss. The financing of the investments may come from internal sources of the ESCo, the customer or an external 

source, such as a credit loan. EPC is a complex service that includes initial energy analysis of the facility, draft 

of concrete saving measures, financing of the project, implementation of the work, and training of service 

personnel. The EPC hasn’t been entrenched in the industrial sphere yet. This may be assigned to a rather 

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problematic justification of the investments and long payback period (Pätäri and Sinkkonen, 2014). Energy 

systems in industrial facilities nowadays encompass various technologies and processes that necessitate high 

level of expertise. The energy systems include mutual interactions of particular elements, accumulation of heat, 

exothermic processes, etc., and optimal solution requires more than just a common approach.  

These projects call for sophisticated tools that perform system analysis and come up with an optimized solution. 

Any attempt for the most efficient operation in this field can be labelled as R&D activities and are usually outside 

the scope of the ESCo or pose a serious risk for the ESCo.  

3. Philosophy of the complex approach 

The complex approach as a whole entails scientific procedures which are applied on real projects (Figure 2). 

New methods and tools are the final product of research work and at the same time also an instrument that 

helps systematize the work and make it more efficient.  

 

 

Figure 2: The complex approach for energy efficiency of buildings and processes in industrial and municipal 

areas 

The complex approach targets three levels of application:  

1. The technological level: all buildings and processes involved in the production and consumption of energy  

2. The time level: in respect to the dynamic behaviour of the systems 

3. The methodological level: a systematic approach from the initial analysis of the system to the design of the 

energy saving measures 

Utilization of particular elements must be carefully considered and modified according to a specific project’s 

requirements. 

3.1 Technological level 
Technology behind the complex approach encompasses analysis of the system as a whole; this means analysis 

of system’s particular elements, their interactions and all external factors affecting operating properties of the 

system. General assignment of energy saving projects must be materialized into concrete saving measures. 

Knowledge from process engineering comes into play as this discipline is based on tailor-made solutions which 

go from the common into more specific. 

The mass and energy balance calculations are a basic tool for analysis and optimization of energy systems. A 

complete balance model of a system, presented in the form of a process flow diagram (PFD) with energy sources 

and all appliances, is based on operational data and subsequent balance calculations. The model may be 

implemented into a software, and various options of saving measures may then be simulated (Figure 3). 

 

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Figure 3: A PFD of a professional laundry care process: a simulation of saving measures (Bobák et al., 2011) 

3.2 Time level 
Time level works with speed of changes to key quantities over the course of time. Daily heat demand profile 

(Figure 4a) shows heat demand throughout the day and is used to describe dynamic properties of the heating 

system in a short-time period. Annual load duration curve (Figure 4b) is another important characteristic 

describing energy systems. The curve is most useful for designing the heat source. Annual heating load duration 

curve shows duration of heat capacity in relation to number of working hours of individual sources, and presents 

changes to heat demands throughout particular year seasons.  

 

 

Figure 4: Examples of (a) a daily heat demand profile and (b) an annual heating load duration curve 

Many times, a mathematical description of dynamic behavior in real-time relations is necessary. The step 

response is often used to describe warming of the source, demand changes, etc. With mathematical description 

of these dynamic properties, it is possible to control the source in compliance with the course of real demands. 

The transfer function or an ordinary differentiation equation can be used for these purposes. All of the above 

described options for a dynamic description may be applied to consumption of power, natural gas and 

compressed air. 

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3.3 Methodological level 
The methodological level of the complex approach is a key aspect of project’s efficiency. Systematic approach 

to energy saving projects includes the following steps: 

1. Analysis of a current state of the energy system and all appliances 

2. Selection of suitable saving measures 

3. Support during implementation of the saving measures  

4. Evaluation of impact of the saving measures 

In-depth knowledge of the specific energy system and all key appliances is very important. Experience proves 

that owners of energy systems lack this kind of knowledge. Most of them have basic assumptions about total 

energy costs and expected life time of key pieces of equipment. First goal of the analysis is to get acquainted 

with technologies of the energy system. It is important to know whether the principles of EM are in place. Scope 

of available operational data and their reliability must be verified.  

Then, modification of the system must be designed. Measures regarding the organization of the facility usually 

concern energy-conscious behaviour of the service personnel. Typical low-cost saving measure is a 

recuperative technology for recovery of waste heat from outlet flows (Bobák et al., 2012). Complex investments 

may include integration of renewable energy sources, complete replacement of heat sources and outdated 

appliances, or substitution of steam system for hot-water one.  

The research team should be able to offer complex services that lead to savings. In terms of investments, this 

concerns the so called basic design, which is a simple project with new technological scheme, layouts of the 

premises and a technical report. Basic design may be used in bidding for tender concerning the supply of the 

technology or energy services. If the energy system is not that large, a competent selection of a particular saving 

measure and basic recommendations for its implementation are enough. The owner is then responsible for the 

implementation. 

Evaluation of benefits of the saving measure does not stop with a mere statement that savings have been 

accomplished. The evaluation of the system efficiency must lead to identification of a specific consumptions; 

this related amount of consumed energy to a unit of a product leaving the process. This unit may have the form 

of a kilogram of processed material, square meter of finished surface, etc. Specific consumption helps better 

evaluate the energy efficiency and compare appliances with an identical product. Long-term monitoring of 

system’s operational parameters is necessary for its gradual optimization. 

4. Experience from case studies 

The complex approach was applied on various case studies. The projects differed greatly in their scope; some 

researched issues were from the commercial sphere (a modern system of production site heating using biomass 

(Máša et al., 2011)), industrial and commercial laundries (Máša et al., 2013), energy system in a wood-

processing facility (Máša and Vondra, 2015) or water desalination and digestate thickening (Vondra et al., 2016), 

whereas other projects dealt with issues from the municipal sphere (e.g. the energy system in the Prague 

National Theatre (Máša et al., 2016). It is obvious that quite different cases are analysed. A first key to 

implementation of complex approach lies in a qualified data acquisition. If there is no reliable data, initial analysis 

ends up being an incomplete list of basic drawbacks of the system. The subsequent design falls back on to a 

conservative solution which does bring a large degree of certainty.  

Many promising measures are not considered as there is no way to estimate their impact more accurately, and 

therefore their potential remains wasted. Other ways for optimization of the facility are also rather limited. A 

second key to success in more complicated energy saving projects is a mathematical model of the system. A 

high-quality model developed using high-quality data is an effective tool for evaluation of a large scope of saving 

measures. A sophisticated analysis of the energy system is time-consuming as well as money-consuming; 

however, it provides a complex design of savings thanks to simulation of several possible solutions. The owner 

receives a reliable and grounded proposal. Once the most promising measures have been implemented, the 

database should be kept updated and the model should be adequately modified. The modified model of the 

system may be then used for identification of an optimal operating regime with respect to external conditions 

(defined inputs of the model). 

5. Conclusion 

Industrial and municipal facilities include a wide array of energy systems, processes and buildings; the owners 

of the facilities, however, often display distrust to ungrounded solutions. Standard procedures of EM do not bring 

satisfying results which opens new ways to sophisticated scientific methods. Three key aspect of a complex 

approach have been identified; these aspects greatly enhance quality of the energy saving measures and bring 

better results:  

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• Application of process engineering principles (especially balance models) 

• Description of the dynamic behaviour of particular system elements (especially heat demand curves) 

• Use of systematic procedure from initial analysis of the system to the implementation of saving measures 

If the project is to be successful, the above aspects must be considered in addition to having a high-quality 

database and a reliable mathematical description of the system. The complex approach provides identification 

of optimum saving measures for the particular facility and efficient support during their implementation. The 

outcome of a future work should be a new methodology for energy saving projects in industrial and municipal 

areas.   

Acknowledgment  

The research leading to these results has received funding from the Ministry of Education, Youth and Sports of 

the Czech Republic under the National Sustainability Programme I (Project LO1202). 

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