Engineering, 2011, 3, 470-477
doi:10.4236/eng.2011.35054 Published Online May 2011 (http://www.SciRP.org/journal/eng)
Evaluation of Energy Consumption for Heating of
Industrial Building in-Situ
Dušan Katunský1, Azra Korjenic2, Jana Katunská1, Martin Lopušniak1
1Technical University of Košice, Faculty of Civil Engineering, Košice, Slovakia
2Vienna University of Technology, Institute for Building Construction and Technology, Research Center of Building
Physics and Sound Protection, Vienna, Austria
Received March 15, 2011; revised March 30, 2011; accepted April 18, 2011
Abstract
Because of the high energy demand required to heat a production hall, the aim of this project is to find out
whether it is possible to verify the heating consuming process for heating with the standard simplified calcu-
lation method [1], especially for cold regions such as Kosice (Slovakia). The energy requirement for heating
a case study industrial building was evaluated using measurements and calculations. During the winter pe-
riod, energy consumption was measured in the selected industrial building according to a validation standard
[2]. The building is comprised of two halls. The measurements were analyzed according to the criteria used
for validating residential and public buildings, with several regression dependencies taken into account in the
resulting evaluation of heating energy consumption. The mathematical dependencies of measured values in
real conditions are shown in this paper. In addition, the building’s heating energy demand was calculated
according to the Austrian standard [3], ÖNORM EN ISO 13790, the simplified calculation method for
non-residential buildings. It was investigated whether the measured values could be replicated using this
calculation. It was found that the precise definition of the internal heat gains is very important.
Keywords: Industrial Buildings, Heating Energy Consumption, Production Halls, In-Situ Measurements,
Envelope Structures
1. Introduction
For decades, increasing productivity was the ultimate
goal of industrial engineering. Because of additional ex-
ternal demands such as public pressure to minimize CO2
emissions and rising energy costs, energy efficiency has
become an increasingly important topic in industrial en-
gineering [4]. Recently, many companies have been
streamlining the economical and intelligent use of elec-
tricity and heat to reduce costs and thereby increase their
competitiveness.
Despite increasingly stringent energy conservation
requirements in all another sectors, new factories are
only required to meet minimum pre-registered U-values
of the building envelope in both Austria and Slovakia.
There are no official programs in place for energy certi-
fication of industrial buildings and energy certificates are
not required by law for this building type.
According to workplace regulations, specific internal
climate conditions must be met. Space heating in indus-
trial halls runs constantly in most buildings. The aim of
this joint project between TU Kosice and TU Vienna was
to evaluate the heating energy consumption using meas-
urements and calculations applied to the case study of an
industrial building with two production halls. The goal
was to determine whether the energy consumption for
heating can be approximated using the simplified method.
The results will determine if the heating energy demand
can be easily calculated for all new factories and renova-
tion projects, and if the building envelope may be rapidly
optimized.
The motivation of this project was the high heating
energy consumption for production halls, especially in
cold regions like Kosice. In Slovakia, there are no ex-
plicit heating energy measurement or calculation stan-
dards for industrial production facilities. The first part of
the analysis deals with in-situ measurements in an indus-
trial hall, applying standard Slovak heating calculations
for residential buildings [5], [6]. The intended results are
to establish the mathematical dependencies of measured

D. KATUNSKÝ ET AL. 471
values in real conditions. In the second part, the heating
energy demand of the building was calculated according
to the Austrian simplified method of ÖNORM EN ISO
13790 for non-residential buildings.
The heating energy consumption of the selected pro-
duction facilities was evaluated using measurements and
calculations. During the winter period, heating energy
consumption was measured in-situ in the chosen build-
ings. The measurements were evaluated according to
criteria valid for residential and public buildings, with
several regression dependencies taken into consideration
in the resultant evaluation of heating energy consumption.
Many calculation methods exist for measuring energy
consumption of residential buildings. It is also possible
to perform on-site measurements of the energy consump-
tion of residential buildings.
2. Requirements for Monitoring in-Situ
Energy Consumption
The halls were monitored in compliance with the Slovak
Standard, STN 73 0550 [2]. This standard outlines bind-
ing preconditions for of resulted values of energy con-
sumption on the heat exchanger before entering into a
building (usually at the base of a house). The purpose of
this standard is to verify the operative energy required
for all residential building types, outlining the same as-
sumptions for internal conditions. In industrial buildings,
the occupancy and uses are different. For this reason,
another task was to assess the extent that the binding
criteria for the energy consumption measurements are
applicable to industrial factory assessments. Some ex-
amples with the analysis of energy use in industrial sec-
tor was published in [7,8].
3. Building Construction of Selected
Industrial Halls
The halls were monitored within the framework of a
grant research project. The investigation was conducted
in one industrial building with two production halls.
Each hall contains development workshops, one classi-
fied as light industrial, and the other semi-heavy indus-
trial [9]. The main structural system of both halls is de-
signed as steel-concrete skeleton. One hall dimension is
36 m (6 × 6 meters), with an 18m span; the overall height
of the industrial building is 7 m. See Figure 1.
The hall envelope is 375 mm thick composed of
“CDm” bricks and lime mortar. Glazed elements are
comprised of single-paned glazed walls with wire-insert
Figure 1. Location plan and sections of the industrial halls.

D. KATUNSKÝ ET AL. 472
reinforcement and single paned skylights with
wire-insert reinforcement, with steel framing. In one hall,
the transparent constructions have a southern orientation,
in the other, a northern orientation. Location plan and
sections of the two industrial halls, and the data logger
locations are presented in Figure 1. The two halls are
connected via an office building.
The building envelopes of the halls were reconstructed
and heat energy demand calculated in the ESP-r simula-
tion program, Figure 2.
3. Monitoring Conditions
Energy consumption was monitored from December 23rd,
2009 to January 24th, 2010 for a total of 32 days. The
halls were measured during the winter period when exte-
rior air temperatures were below zero. This duration was
chosen as standard STN 73 0550 [2] states that the
measurement interval must be over 30 days. The internal
and external climate parameters were recorded with av-
erage daily interior and exterior air temperatures for both
halls. The interior air temperature was measured at seven
heights, in the middle of the considered operation, which
is not in compliance with the requirement for a sensor to
measure a maximum space of 50 m2. Determining gener-
ally valid calculation criteria of the average daily interior
temperature of an industrial hall is difficult, in view of
the fact that the dynamics of the temperature parameters
in the space is very high, e.g. in horizontal and vertical
axes. The hall interior is shown in Figure 3.
The total heating energy consumption measured dur-
ing operation is an attempt to evaluate the validity of the
binding criteria for measuring energy consumption
on-site for industrial operations.
4. Results of Site Measurements According
to the Standards
The heating energy consumption values were obtained
from the Kosice heat exchanger station N.1607 and are
given in Table 1.
5. Calculations According to the Austrian
Standards
At present, there is no regulation that requires an energy
certificate for industrial buildings. Directive 2010/31/EU
of the European Parliament and of the Council of 19
May 2010 requires that,
“Member States may decide not to set or apply the re-
quirements of improvement of the energy performance of
buildings to the following categories of buildings:
(c) temporary buildings with a time of use of two
years or less, industrial sites etc.
The heating and cooling needs of a building / building
elements in Austria are calculated in accordance with
ÖNORM EN ISO 13790 [3] using the monthly balance
method. The energy certificate, i.e., the monthly heating
Figure 2. Simulation model of one industrial hall.

D. KATUNSKÝ ET AL. 473
Figure 3. View into hall interior.
demands, are required to be calculated only for non-
residential buildings listed in Table 2.
For non-residential buildings, the heat gain from
lighting is identified and separated from heat transmitted
by people and equipment. Table 2 shows the typical
values for the internal gain from appliances and persons,
and the typical electrical lighting output for
non-residential buildings following Austrian standard
ÖNORM B 8110-6.
The two industrial halls were calculated following the
Austrian monthly balance method using the typical val-
ues from other non-residential building types: convention
centres, sports arenas, or retail.
The results are presented in Table 5.
6. Evaluation of Measured and Calculated
Values
The measurements have been evaluated by validated
calculation relations for the monitoring period per day,
i.e., for 32 points [2]. An alternative evaluation has
been conducted per file for two days, i.e.16 points, and
for four days, i.e. 8 points. From the drawn graphs, it
was evident that the energetic-thermal relations have a
linear character gained by linear regression dependence.
This has been attained from the file of heating energy
consumption gains reading and from the temperature
difference θai – θae, or from day/degrees—Dper. The
energy consumption for heating as a function of
day/degrees is sought by means of linear regression in
the form:
2
bp per
EaDb


 (1)
where a, b are regression coefficients for the equation of
a linear calculation according to relations (11) and (12)
from the STN 73 0550 standard (see Table 3).
σ is a conclusive deviation of the file calculated ac-
cording to the relation (13) of the standard STN 73 0550.
Dper—day/degrees.
Heating energy consumption for condominium storeys
under standard conditions is determined for a prescrip-
tive (directive) number of day/degrees according to the
relation,

3422
bp bp
Eab MwhVyear


 

 (2)
The purpose of the measurement evaluation was to
compare the calculated specific heating consumption for
1 m3 found by calculating the heating value of a built up
space for the whole heating period using the climatic
day/degrees of Košice D = 2834 K. The daily output is
determined according to the relation:

3422
bpD bp
Eab MwhVyear

 

(3)
Table 1. Recorded heating energy consumption value s in the sele cted production hall.
Date Recorded heat exchanger value
(MWh) Date Recorded heat exchanger value (MWh) Date Recorded heat exchanger value (MWh)
12.23. 105,013 01.03.121,004 01.14. 134,517
12.24. 106,477 01.04.122,135 01.15. 135,533
12.25. 108,051 01.05.123,588 01.16. 136,435
12.26. 109,312 01.06.124,587 01.17. 137,749
12.27. 110,688 01.07.125,773 01.18. 139,016
12.28. 112,789 01.08.126,927 01.19. 140,183
12.29. 114,813 01.09.128,069 01.20. 141,859
12.30. 116,325 01.10.129,554 01.21. 142,892
12.31. 117,624 01.11.130,476 01.22. 143,248
01.01. 118,871 01.12.131,674 01.23. 144,392
01.02. 119,959 01.13.133,060 01.24. 145,524
Total monthly consumption 40,511 MWh

D. KATUNSKÝ ET AL. 474
Table 2. Typical internal gain values from appliances and
persons, qp, and typical average lighting levels for non-
residential buildings, ÖNORM B 8110-6.
q
h
p
W/m² W/m²GFA
Office building 3.75 3.7
Kindergarten and Primary School 3.75 2.8
Secondary School and Universities 7.5 2.8
Hospital Facilities 7.5 9.4
Nursing Homes 3.75 5.8
Pensions 3.75 3.9
Hotels 7.5 7.4
Restaurants 7.5 3.1
Conference Centres 7.5 3.1
Sports Arenas 7.5 4.3
Retail 3.75 8.1
Table 3. Energy consumption evaluation according to STN
73 0550.
Reading period per
(# of days) 1 day 2 days 4 days
a 0.0743 0.0779 0.0665
b 0.1859 0.2677 1.1967
Ebp
[MWh/(Vbp·year)] 254.441 266.842 228.759
E1
[kWh/(m3·year)] 54.578 57.238 49.069
EbpD
[MWh/(Vbp·year)] 210.752 221.036 189.658
E1D
[kWh/(m3·year)] 45.206 47.412 40.682
IED (-) 0.9889 0.9904 0.9916
σ (-) 0.2982 1.3500 2.2746
The energy consumption for heating, E1, is determined
using 1m3 of built up volume for one year according to
the relation:
 
3
11000 bp bp
EaEVkWh myear


 

 (4)
To prove measurement accuracy, the correlation index,
EED, is calculated according to relation 15 of the standard
STN 73 0550 [2]. The measurement can be considered if
the correlation index, IED ≥ 0.7. The heating energy con-
sumption measurement evaluation is given according to
various intervals (per = 1, 2, 4 days) in Table 3.
The in-situ heating energy consumption measurement
can be considered proven in this given case as the corre-
lation index, IED , is higher than 0.7 for all reading in-
tervals as required by the standard. The highest correla-
tion index is for the reading interval per 4 days. This is
why the data at this interval can be considered for the
result of the heating energy consumption measurement
evaluation for in-situ conditions.
The in-situ energy consumption measurement calcula-
tion was conducted considering various types of regres-
sion [10]. The calculations were carried out for regres-
sion shapes with the resultant coefficients a, b, eventu-
ally c. Their values are given in Table 4.
The calculation results of the investigated industrial
halls using the Austrian monthly balance method with
typical values from other non-residential building types:
convention centres, sports arenas, or retail is shown in
Table 5.
In the second step, the average hourly load of the used
ten turning machine (10 × 400 W = 4000 W) and the heat
of twenty persons (20 × 200 W = 4000 W) were assumed
as internal heat gains in the calculation. Per unit area, the
internal heat gains are 12.35 W/m2 from machines, and
4.5 W/m2 from lighting. This variant is presented in the
second line of Table 5.
Evaluating the difference in values shows that knowl-
edge of internal gains is important for the calculation
accuracy and should be defined as precisely as possible.
The user profile of similar non-residential buildings can
also be used as estimation in the planning phase.
7. Discussion of Conclusions
It is possible to consider the increase in energy consump-
tion when reading the increasing energy consumption
in-situ values, from the lowest to the highest, besides the
Table 4. Coefficients found considering regression dependences of energy consumption according to readings on individual
days.
Current number Considered regression type coefficient “a” coefficient “b” coefficient “c”
1. Power 1.7839 −0.1493 0.0000
2. polynomial 0.0005 −0.0324 1.6255
3. exponential −0.0146 1.5522 0.0000
4. logarithmic −0.1736 1.7084 0.0000
5. Linear-descending −0.0162 1.5336 0.0000
6. Linear-ascending 0.0546 0.0000 0.0000

D. KATUNSKÝ ET AL. 475
Table 5. Measured and calculated heat energy demand by
different user-profiles of interior gains.
Heat Energy
Demand kWh/M
Difference
kWh
Measured 40 511.0 -
Calculated with real interior gains 40 145.4 365.6
User Profile for Retail 41 963.6 1452.6
User Profile for Sports Arenas 41 982.1 1471.1
User Profile for Conference Centres 42 426.5 1915.5
energy consumption dependences on the number of
day/degrees when the graphic dependence is not always
ascending. In such cases, energy consumption considered
with linear regression, can be calculated according to the
linear equation,
0.0292 0.7832yx x

 (-) (5)
Theoretically, the in-situ energy consumption calcula-
tion can be considered if the coefficients a = 0.0292. b =
0.7835 are substituted in relation (2). Then the calculated
value, E1 = 21.6 [kWh/(m3.year)] may be used which is
far lower energy consumption than that determined by
the calculations from the standard. The monitored energy
consumption from December 23rd, 2009 to January 23th,
2010 is presented in Figure 4.
Figures 5-7 show a very strong correlation between
heating energy use and degree days.
Figure 4. Measured energy consumption values in the case study hall from 23rd of December, 2009 to 23rd of January, 2010.
Figure 5: Measured energy consumption values in the c a se study hall—daily reading period.

D. KATUNSKÝ ET AL. 476
Figure 6. Measured energy consumption values in the case study hall—2 day reading period.
Figure 7. Measured energy consumption values in the case study hall—4 day reading period.
8. Conclusions
This investigation aimed at describing the use of heating
energy and the potential heating energy savings in the
industry sector, using calculations and measures in two
case study halls. The location, use, and internal environ-
ment, as well as the construction details of the building
play an important role in the overall energy consumption
of an industry hall. These factors establish the hall de-
signs and many of the individual factors affecting energy
use. Rising energy costs forced modern industry hall
design to consider energy efficiency, but no regulation
currently exist with defined values for heating energy.
When seeking influential energy use factors, analysis
shows that heating energy use is more or less constant. If,
despite that, the real increase is considered, e.g. the daily
energy input increase based on measured days, then the
considered regression results will be as shown in Table 4.
In calculation, E1, it can be stated that no considered re-
gression shape leads to correct results, with the exception

D. KATUNSKÝ ET AL. 477
of linear ascending regression. This regression can be
considered for comparison with the energy consumption
calculation according to values read from the heat ex-
changer station.
The heating energy consumption values calculated
according to the current standard, STN 73 0550 [2], most
closely correlate to the measured energy consumption
values if the calculation is conducted with the aid of co-
efficients “a” and “b” as the product of the line gradient
in the linear regression dependence considering
day/degrees. No other functional dependence regression
shape of the energy increase per day/degrees leads to the
correct prediction of energy consumption measurement
in-situ.
It is not easy to benchmark or to define ‘the standard
hall’ because of the high diversity in the shape and type
of industrial halls. There are several types of industry
hall where energy use is comparable. However, varia-
tions in use and equipment type should be identified and
categorized to define the regulations for heating energy
consumption. Energy can also be saved by adjusting set-
tings and better maintenance of the heating system. For
evaluation of energy consumption in industrial buildings
it can be multi-criterion analysis used [11].
9. Acknowledgements
This contribution originated in the development and so-
lution of the project ITMS
“26220220050”—Architectural, Structural, technological
and economical aspects of energy efficiency building
design“. The project is financially supported by the EU
structural resources within operative program of research
and development OPVaV-2008/2.2/01-SORO.
10. References
[1] STN 73 0540, “Thermodynamic Properties of Structures
and Buildings,” Thermal Protection of Buildings, Part 1-4.
2002
[2] STN 73 0550, “Measurement of Energy Consumption in
Situ”.
[3] ÖNORM EN ISO 13790, “Energy Performance of
Buildings—Calculation of Energy Use for Space Heating
and Cooling,” ISO 13790, 2008.
[4] Directive 2010/31/EU of the European Parliament and of
the Council of 19 May 2010.
[5] K. Jana and K. Dušan, “Špecifiká Pri Výpočte Potreby
Energie Výrobnej Budovy,” Zborník z Konferencie s
MedzinÁRodnou ÚČasťou Budova a Energia 6, Vysoké
Tatry, Podbanské, 12-14 October 2006, pp. 195-200.
[6] K. Jana and K. Dušan, “Hodnotenie Energetickej Nároč-
nosti Výrobných Priemyselných Budov,” 32 Medz-
inárodná Konferencia Katedier/Ústavov Pozemných Sta-
vieb SR A ČR: Zborník Príspevkov z Konferencie s
Medzinárodnou Účasťou: Košice, Košice, 17-19, Sep-
tember, 2008, pp. 45-49.
[7] H. Akbari and O. Sezgen, “Analysis of Energy Use in
Building Services of the Industrial Sector in California:
Two Case Studies,” Energy and Buildings, Vol. 19, No. 2,
1992, pp. 133-141. doi:10.1016/0378-7788(92)90007-4
[8] S.-I. Gustafsson, “Refurbishment of Industrial Build-
ings,” Energy Conversion and Management, Vol. 47, No.
15-16, 2006, pp. 2223-2239.
[9] STN 73 5105, “Industrial manufacturing buildings,”
1995.
[10] Lopušniak, Martin, Katunský, Dušan, “Interaction of
Selected Parameters within Design of Suitable Working
Environment,” Healthy Buildings 2006: Design and Op-
eration of Healthy Buildings, 4-8 June 2006, Lisboa, pp.
147-152.
[11] D. Chinese, G. Nardin and O. Saro, “Multi-Criteria
Analysis for the Selection of Space Heating Systems in
an industrial Building,” Energy, Vol. 36, No. 1, 2011, pp.
556-565. doi:10.1016/j.energy.2010.10.005