energy-efficient retrofitting strategies for healthcare

Alexandria Engineering Journal (2020) xxx, xxx–xxx

HO ST E D BY

Alexandria University

Alexandria Engineering Journal

www.elsevier.com/locate/aejwww.sciencedirect.com

Energy-efficient retrofitting strategies for

healthcare facilities in hot-humid climate:

Parametric and economical analysis

* Corresponding author.

E-mail address: [email protected] (M.A. William).

Peer review under responsibility of Faculty of Engineering, Alexandria

University.

https://doi.org/10.1016/j.aej.2020.08.0111110-0168 � 2020 Faculty of Engineering, Alexandria University. Production and hosting by Elsevier B.V.This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Please cite this article in press as: M.A. William et al., Energy-efficient retrofitting strategies for healthcare facilities in hot-humid climate: Parametric and ecoanalysis, Alexandria Eng. J. (2020), https://doi.org/10.1016/j.aej.2020.08.011

Micheal A. William a,*, Aly M. Elharidi a, Ahmed A. Hanafy a, Abdelhamid Attia b,

Mohamed Elhelw b

aMechanical Engineering Department, College of Engineering & Technology, Arab Academy for Science, Technology &Maritime Transport, Alexandria, EgyptbMechanical Engineering Department, Faculty of Engineering, Alexandria University, Alexandria, Egypt

Received 7 April 2020; revised 6 July 2020; accepted 14 August 2020

KEYWORDS

Hot-humid climates;

Thermal comfort;

Healthcare facilities;

DOAS;

Environmental perception;

Economical analysis

Abstract All living beings depend on energy for survival, and modern civilizations will continue to

thrive only if existing sources of energy can be developed to meet the growing demand. With the

universal urge to reduce power usage in the building environment, there are broad discrepancies

between energy efficiency intention and the realistic operation of buildings. Implementing current

mitigation strategies tends to be gradual and requires a ‘whole-system’ approach to the issue.

In Egyptian buildings, energy demand increased dramatically with the increasing necessity to

acquire indoor thermal comfort conditions. Simultaneous growth in residential and commercial

developments necessitate increasing power production to face new demands. Energy needs in facil-

ities are growing annually due to the expansion in HVAC (Heating, Ventilation & Air Condition-

ing) systems operating hours. Minimizing power demand and encouraging the use of green energy

sources, protecting the planet from global warming impacts, and depleting the ozone layer is ben-

eficial.

High temperatures and high humidity levels in hot and humid climate zones such as Alexandria

in Egypt cause human discomfort, resulting in high HVAC energy consumption. Apart from med-

ical equipment, power, and infection controls, hospitals utilize substantial amounts of HVAC

energy. To clarify Egyptian hospitals ’ energy consumption, the on-going case study is conducted

on a hospital accessible to the researcher at Alexandria, Egypt. The purpose of this study is to

explore medical facilities’ energy requirements and to assess the possible energy savings of present

buildings in Egypt. Using the DesignBuilder simulator platform, a prototype was built for medical

institution underdevelopment. Depending on the hospital’s construction, mechanical consultants’

documentation, and EUI, the model is validated. Firstly, the initial model is adjusted to the latest

outdoor design conditions and weather database information endorsed by ASHRAE (American

nomical

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https://doi.org/10.1016/j.aej.2020.08.011


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2 M.A. William et al.

Please cite this article in press as: M.A. Williaanalysis, Alexandria Eng. J. (2020), https://

Heating, Refrigeration, and Air Conditioning Engineers Society) and NREL (National Renewable

Energy Laboratory). Analysis of energy-efficient methods influencing yearly HVAC power utiliza-

tion and total building power is examined. The analysis gives information about the increase in

energy efficiency in medical institutions achieving thermal comfort in Alexandria that would allow

designers to sufficiently limit buildings ’ energy consumption.

For the autonomous temperature and moisture control and influence on the HVAC system, a

DOAS (Dedicated Outdoor Air Systems) was introduced asserting substantial energy-savings for

both HVAC and the entire building electricity utilization.

The study reveals that about 67% energy savings and operating costs can be achieved through

efficient retrofitting and systems right sizing.

Through economic analysis, this study provides new energy opportunities for new medical facil-

ities in hot-humid climatic regions.

� 2020 Faculty of Engineering, Alexandria University. Production and hosting by Elsevier B.V. This is an

open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

1. Introduction

Based on the recently released report of the EEHC (Egyptian

Electricity Holding Company), Egypt’s installed electric abilityas of 2017/2018 was 55.2 GW (gigawatts), higher than the pro-jected installed capacity of 45 GW in 2016/2017 by a dramaticincrease of about 22.5% [1]. Generating power depending on

petroleum-based fuel burning produces CO2 emissions fromcombustion. Due to the continuous electrical needs of every-day life, the consumption of fuel is increasing daily contribut-

ing to the energy crisis. Due to the efficiency of power plantsand transmission lines, 1 kWh (kilowatt-hours) consumptionrequires the production of 3 kWh [2]. Global energy use led

to a 44% increase in carbon emissions from 2000 to 2015(EIA, 2019) [3]. Greenhouse gases are among the most danger-ous crises on the planet, contributing to global warming and

ozone depletion. Human actions are the primary source of glo-bal warming and greenhouse gases as CO2 which absorbsinfrared radiation contributing to climatic change and temper-ature rise [4]. Large air-conditioning systems are necessary for

hot zones due to climate and temperature changes [4]. In com-mercial buildings where the HVAC equipment invests a sizableportion of the demand for energy, the opportunity for energy

savings is greater. Several benefits could be attained fromenergy-efficient equipment such as:

(1) New power plants are less required.(2) Greenhouse gas emissions will be reduced as less elec-

tricity will be generated, meaning fewer greenhouse

releases from power stations.(3) Lowering electricity bills, thereby increasing the pur-

chasing power of customers for other goods supportinglocal industries.

(4) Prevent future electricity scarcity danger related toincreasing power demand.

Based on the EEHC’s 2016/2017 report, electricity use inthe commercial and utility sectors accounted for almost 17%

of Egyptian energy usage [1]. In commercial properties, the uti-lization of air conditioning systems constitutes approximately56% and the lighting systems consume approximately 21%

of the total energy used [5]. HVAC systems constitute a largeshare of energy consumption due to long operating periodsin healthcare facilities. Because of this dilemma, engineersand designers are striving economic energy management pro-

m et al., Energy-efficient retrofitting strdoi.org/10.1016/j.aej.2020.08.011

cedures to save buildings’ air conditioning systems and, conse-quently, protect the environment from global warming. Thecomputer simulation resources currently available can mainly

predict energy utilization for each load type (i.e., energy usedby HVAC, lighting fixtures, appliances, etc.) [6]. This energyuse data is generated using simulation tools such as Energy-

Plus, OpenStudio, Revit, DesignBuilder, eQuest, etc.

2. Literature review

Yusoff et al. [7], argue that buildings utilize an immenseamount of total energy use through HVAC, artificial lighting,electrical appliances. Wardah additionally relates to the posi-

tive impact of the legislative and non-governmental organiza-tions’ improving energy efficiency in buildings through aplethora of policies and techniques. Karmany et al. [8], express

the linkage between sustainable development and green-building assessment frameworks. They have articulated theadvantages of environmental design and development througha green building assessment framework of paybacks in three

phases; (1) human-level advantages, (2) nation-level advan-tages, and (3) globe-wide advantages. Gonzalez et al. [9],express that alternative energy sources and energy manage-

ment all around decrease carbon footprint in both energy gen-eration processes and activities, including energy-efficiencyimprovement. Dutta et al. [10], research shows the effect of dif-

ferent varieties of glazed windows on decreasing both air con-ditioning load and energy usage. The investigation givesattention to the selection of windows from financially accessi-ble products, with the goal that property managers should

choose a reasonable model of glasses from the market basedon the outcome of the analysis to minimize the energy utiliza-tion of the property. Ahn et al. [11], discovered using modeling

techniques that when used with the control method, LEDlighting reduces energy use by 20–40% of whole-buildingenergy use. Jenkins et al. [12], investigate a six-story building,

light savings achieved annual savings of 56–62%, and decar-bonization of nearly 3 tons are expected by modifying thelighting type. Sabry et al. [13], explore the influence of walls

and roof insulation on energy utilization and CO2 reductionin Egyptian residential buildings through DesignBuilder mod-eling software. Approximately 40% reduction in the energydevoured by the HVAC lead when using thermal insulation

in exterior walls and roofs, these reductions represent a signif-

ategies for healthcare facilities in hot-humid climate: Parametric and economical

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Energy-efficient retrofitting strategies for healthcare facilities in hot-humid climate 3

icant decrease in operating costs. William et al. [14], examinedthe influence of envelopes on the HVAC as well as the overallconsumption of building energy in commercial properties in

Egypt, using DesignBuilder simulations. Elharidi et al. [15],postulate that system efficiencies (HVAC, lighting, appliances)and tenant practices (e.g., equipment use, temperature swings)

are also distinct as main energy consumption variables, eachwith a potential of nearly 30% compared to existing conven-tional workplaces. Conceivable strategic plans are recom-

mended to encourage energy-efficiency and energy-consciousbehavior patterns that together could halve the energy needsin conventional workplaces.

For the purpose of determining energy efficiency perfor-

mance measures comparing energy usage and best practicecases, AbdulRazek [16], begin to develop methods for energyefficiency of Lebanese constructions in order to contrast per-

formance in the current structure with nationally and interna-tionally standards. Furthermore, he asserts that as per theANSI/ASHRAE/USGBC/IES standards 189.1, the mean

annual consumption in healthcare facilities is 200 kWh/m2.An examination by the Spanish Institute for Energy Diversifi-cation and Saving (IDAE) emphasized that the emission of

CO2 is profoundly influenced by the building industry, in par-ticular the medical services sector, that accomplished the high-est energy intensity correlated with the various activities itencompasses [17]. Carbonaria et al. [18], study poor level

energy efficiency in health facilities and public treatment cen-ters, primarily due to the age of structures and a regular main-tenance plan and their negative environmental impact. In the

article, they proposed enhancement techniques include insu-lated envelopes, upgrading of mechanical and lighting systems,implementation of alternative energy, proper regulation of

systems.Hoyt et al. [19], contemplated expanding the cooling set-

point from 22 �C to 25 �C, around 29% energy savings were

accomplished. He additionally referenced that in hot atmo-spheres expanding cooling setpoints will be increasingly profi-cient. Memarzadeh et al. [20], argue that several factors affecthospital infection as: patients’ infection susceptibility, operat-

ing rooms cleanliness and HVAC system as ventilation airchange rate and airflow direction. Different national and inter-national standards suggest the air-conditioning systems for

operating theatres. He also argue that the temperature shouldbe between 16.67 �C and 26.67 �C while maintaining positivepressure. He recommends that average 15 ACH for systems

operating all outdoor air and 25 ACH for systems recirculatingair as increasing ACH, via ventilation, to high levels results inexcellent removal of particles. Attia et al. [21], study the oper-ating theatres ventilation requirements and pressurization. He

recommends 20 ACH for proper ventilation and concludedthat 25 Pa is sufficient for operating theatres cleanliness.

Zhang et al. [22], examine the DOAS, becoming one of the

most frequently implemented efficient technology. Kim et al.[23], assess the energy performance of a DOAS as a separablesystem approach that handles the latent and sensible HVAC

loads separately. As driven in earlier research by Williamet al. [24], implementing the DOAS in medical services build-ings in hot-humid atmospheres, immense energy savings can

be achieved throughout the whole year.The literature survey indicates that energy-efficiency is vital

research that policymakers put their efforts through. To thebest of researchers’ knowledge, the literature has a gap in

Please cite this article in press as: M.A. William et al., Energy-efficient retrofitting straanalysis, Alexandria Eng. J. (2020), https://doi.org/10.1016/j.aej.2020.08.011

energy conservation in hot-humid climatological zones suchas Alexandria, Egypt. This paper aims at filling that gap withthe aid of economic analysis by investigating the case in a hos-

pital accessible to the researchers at Alexandria, Egypt.

3. Methodology

Depending on the accessibility of documentation, a hospital inAlexandria, Egypt, is selected for the examination at hand.DesignBuilder modeling software has been used to generate

the initial model, which is then verified depending on Egyptianmechanical and construction professionals to account forenergy correlations among building system components. The

energy efficiency of the building’s initial, as well as other mod-els, are tested to verify achievable energy savings. Design-Builder is selected as it is a user-friendly GUI for the

EnergyPlus software established by BTO (Building Technolo-gies Office) from the DOE (US Department of Energy).Depending on the correlations between climatic conditions,construction envelope, interior gains, and HVAC systems,

DesignBuilder analyzes the use of building energy.In the building examination, the manual setup below was

utilized on DesignBuilder:

1. Developing the initial healthcare model’s architectural fea-tures, characterizing each space.

2. Developing for Alexandria, Egypt, an ASHRAE baselinemodel utilizing the current ASHRAE design climatic condi-tions 2017.

3. Applying ASHRAE standards (62.1–2016, 170–2017, 90.1–

2016), AIA, GGHC to the baseline model.4. Performing simulations for the various models demonstrat-

ing that half (or more noteworthy in hot-humid atmo-

spheres) energy reductions can be achieved when applyingthe energy-efficient concept configurations.

5. Introducing a DOAS to the healthcare facility model.

The means of accomplishing energy conservation are visu-ally presented in Fig. 1.

4. Climatic design

The most influential factors of the building load, the effi-

ciency of HVAC systems, and the use of energy in buildingsare the climate and outside design conditions. The energy useof a building results directly from climate building applica-tion and building orient. The most severe design conditions

of summer are not at all recommended for use in comfortapplications where design conditions are rarely appropriate,as maximum temperatures in ordinary summer seasons do

not exceed 3 h [25]. As occasions under hot climate aremostly of short duration, therefore, sacrificing comfort undertypical conditions to meet occasional short extremes is not

recommended [25].Most Egyptian HVAC designers assess the external design

temperatures in the Alexandrian climate as (DBT 40 �C,WBT 30 �C) as outlined in Table 1, prompts over-sizing ofHVAC equipment and systems in the long run, resulting inenergy misuse. The prescribed ventilation rates and 2017 ASH-RAE design weather data (DBT 33.2 �C, WBT 22.4 �C) out-lined in Table 1 [26], are prescribed, and the information

tegies for healthcare facilities in hot-humid climate: Parametric and economical


Fig. 1 Flowchart of the modeling process.

Table 1 Climatological conditions Alexandria, Egypt.

Temperature Initial Model ASHRAE Baseline Model [26],

DBT �C 40 33.2

WBT �C 30 22.4


provided by EnergyPlus in the weather database in Alexan-dria, Egypt [27], is prescribed in Fig. 2.

5. Characterization of the case study

This research is investigating the case at an Alexandrian med-

ical facility in Egypt. The facility consists of five stories ofapproximately 10,000 m2 as seen in Fig. 3.

Hospital plans are classified and described into various

types displayed as well as and current HVAC system specifica-tions in Appendix A.

5.1. Building envelope

This section explains in detail building materials.

5.1.1. Glazing type

As quoted in ASHRAE [28], the heat that passes through theglass is the greatest load component: windows, glass dividers,

and skylight windows. If the structure is designed to fulfillthe energy expectations of ASHRAE Standard 90.1-2010 or

Please cite this article in press as: M.A. William et al., Energy-efficient retrofitting stranalysis, Alexandria Eng. J. (2020), https://doi.org/10.1016/j.aej.2020.08.011

later, the coating formation will be essentially double low-eglazing. Single glazing believed among most HVAC engineers,

mostly to be as safety factors, triggers higher cooling loadspromoting to over-size systems. In the article, the suggesteddouble-glazed windows by Saint-Gobain UK corporation lists

(High-Performance Glass Solutions) as Table 2 supplants sin-gle clear glazed windows of both initial and baseline modelanticipated by most Egyptian air conditioning engineers.

5.1.2. Exterior walls

There are less cooling capacity demands for a well-insulatedsystem [29]. As the Egyptian development and construction

industry, the initial model and ASHRAE baseline model ofthe hospital were developed. Walls were then insulatedemploying advised thickness of polyurethane by EgyptianHousing and Building National Research Center [30], and

the Guide for Energy Efficiency in Buildings [31]. Table 3 rep-resents the typical wall layers of the different simulatedmodels.

5.2. Ventilation requirements

The ventilation values were based on room type as per the AIA

[32], standard 62.1–2016 [33], and standard 170–2017 (ASH-RAE) [34].

5.3. Internal loads

The loads produced within the building shell are interior loads.



Fig. 2 Weather file records of Alexandria, Egypt [27].

Fig. 3 Hospital Overview.

Table 2 Glass characteristics.

Model Initial & baseline Modified model

Glazing Type 6 mm Single

Clear Glass

6 mm Double Low-e

Colored Reflective Glass

6 mm Air gap

U-factor (W/m2 �C) 5.778 2.235

SHGC 0.819 0.15

Table 3 Synopsis of the building construction.

Model Initial & baseline Modified energy model

Exterior

walls

Construction 200 mm Common

Brick + 50 mm Cement

Plaster

200 mm Common

Brick + 50 mm Cement

Plaster + 25 mm

Polyurethane

U-factor

(W/m2 �C)1.924 0.708

Roof

Construction 20 mm Cement

Plaster + 180 mm

Hurdy Block + 20 mm

Moisture

Insulation + 50 mm

Sand Layer + 25 mm

Mortar Layer + 30 mm

Tiles

20 mm Cement

Plaster + 180 mm

Hurdy Block + 20 mm

Moisture

Insulation + 50 mm

Sand Layer + 25 mm

Polyurethane + 25 mm

Mortar Layer + 30 mm

Tiles

U-factor

(W/m2 �C)2.27 0.75


5.3.1. Lighting loads

In any building energy use, lighting load clearly shows twice. Itfirst emerges as a power of light. A part of that energy appearsagain as a load on the air conditioning system at that point.The heat generated through the lights is extracted by extra


power by HVAC [28]. The air conditioning load brought aboutby lighting is firmly identified with the power utilization of

bulbs. The new LED bulbs MIYAOKA [35], recommended,as Table 4 replaced old bulbs of the early models suggestedby most Egyptian HVAC Engineers in this article, ensuring

the same LUX and Lumens are delivered in both cases.

5.3.2. Occupant density

According to AIA [32], and ASHRAE [33], occupancy values

by room type are specified in Table A2 in the appendix.



Table 4 Density of lighting power.

Model Initial & Baseline Modified Model [35]

LPD (W/m2) 40 7.5


5.3.3. Plug loads

Loads of plugins are electricity used by appliances typically

attached to electric sockets on a regular basis, such as work-places and common devices, including PCs and others. Plugload densities, classified in appendix, are recommended by

the GGHC [36], and ASHRAE Standard 90.1–2016 [37], andin all computed models they remain steady.

Fig. 4 Convention

Fig. 5 Proposed


Figs. 4 and 5 briefly introduce both conventional and pro-posed HVAC system diagrams.

In recirculating ventilation systems with one or more con-

ventional air handlers condition a mixture of outdoor andrecirculated air (supply air) to more than one ventilation zone.Traditional air handling units provide only one outdoor air

fraction, while each zone may have different outdoor air frac-tion as standards requirements, meaning that some zones mayreceive over ventilation [38].

The proposed system is a viable alternative to all-air HVACsystems, delivering 100% fresh ventilation outdoor airrequired. The air is supplied at lower dew-point temperaturesenabling it to handle all space latent load and part of the sensi-

ble load, thereby decoupling the space sensible and latent loads.

al VAV system.

DOAS system.



Fig. 8 Monthly Hospital Initial Model Energy Analysis (MWh).


6. Model validation

The first step is simulating the building based on the latestODC presented by ASHRAE listed in Table 1 with Alexan-

dria’s weather database, published by EnergyPlus [27], alteringthe prescribed ventilation prerequisites [32,33,34], and actualiz-ing a VAV (Variable Air Volume). As the hospital is still under

construction, Fig. 6 illustrates the ASHRAE baseline modelenergy prediction validated based on a hospital studied previ-ously by Radwan et al. [39], in Alexandria, Egypt with about7% error in the total energy use intensity (EUI).

6.1. Initial hospital energy utilization

The initial model is contrasted and findings obtained from the

hospital consultant to test the validity of energy-saving futuremodels. The energy consumption assessment is carried out byevaluating each component’s contribution to annual energy

use in the initial building. Fig. 7 demonstrates the power usageof the facility components while Fig. 8 depicts the monthlydemand for energy.

6.2. Factors affecting HVAC oversizing

In the initial model, several safety factors are manipulated tomake instances of how and where load estimates can be over-

stated leading to an over-sized system [40].The predictions of the initial model load are evaluated for:

Severe Weather TemperaturesPoorly insulated envelope (windows, walls, roof)

Fig. 6 The simulation validation.

Fig. 7 Facility’s initial energy utilization.


A higher density of lightsCruelest-case scenario (integrating almost all safetyfactors).

The indoor environments are adapted as ASHRAE 170-2017 guidelines and the outside design conditions are accli-

mated to Alexandria, weather design conditions as ASHRAE[26], from the extremely high temperatures used by most Egyp-tian HVAC engineers as in Table 1. Such adjustments areexpressed to designers intending to add a cushion to the system

size a load decrease rate of approximately 30% was accom-plished by just pursuing ASHRAE 2017 design conditions,as shown in Fig. 9.

7. Results and discussion

The consequences of various energy-saving criteria applied are

examined underneath to assess the impact of each parameteron energy efficiency. Every variable is focused exclusively onthe energy consumed. Criteria are described below, with each

diagram demonstrating its influence.

7.1. Initial model vs ASHRAE recommendation (ASHRAEbaseline)

Remodeling ODC from the ASHRAE recommendations tothe most engineers and expert data in Egypt listed in Table 1.Approximately 25% of energy usage in HVAC energy demand

and around 12% in building power usage as shown in Fig. 10.Fig. 11 shows the initial model’s energy breakdown analysis.

Fig. 9 ODC – related Cooling load reduction.



Fig. 10 Annual HVAC Energy Use due to Retrofitting (MWh).

Fig. 12 Whole Building Energy Use Performance due to

Retrofitting (MWh).

Fig. 11 ASHRAE Baseline Model Monthly Energy Analysis

(MWh).

Fig. 14 Insulation Model Monthly Energy Analysis (MWh).

Fig. 13 Glazing Model Monthly Energy Analysis (MWh).


As appeared in Fig. 12, about 12% of whole-building energysavings are achieved.

The consequences of various energy-saving criteria appliedare examined underneath to assess the impact of each param-eter on energy efficiency. Every variable is focused exclusively

on the energy consumed. Criteria are described below, witheach diagram demonstrating its influence.

Fig. 12 shows the impact of appropriate design contempla-

tions influenced the yearly whole-building energy use diminish-ing the energy use by about 12%.

The outcomes are then contrasted with the ASHRAE Base-line model as a source of perspective.


7.2. Glazing type

Low-E double glazing, that is primarily covered with a heat-reflective coating of metallic oxide, thus allowing light to passit, decreases the use of HVAC energy by about 5%. Fig. 13

demonstrates the energy decomposition of the glazing model.In whole-building energy consumption, nearly a 2% reductionwas accomplished compared with the reference ASHRAEmodel.

7.3. Thermal insulation

The addition of Polyurethane insulation to the construction

came about in diminishing around 16.5% in HVAC Energyconsumption as indicated in Fig. 14. Approximately 7% ofsavings in entire building utilization was accomplished.

7.4. Lighting power density (LED model)

Throughout this assessment, the power density headlamps in

both old models of the healthcare facility, which are assumedby the majority of Egypt’s HVAC experts (40 W/m2), are mod-ified to modern LED bulbs with nearly (7.5 W/m2) [35]. Theenergy elimination of about 21% of HVAC energy usage is

accomplished as seen in Fig. 15.LED lightings are extremely productive to be utilized in

buildings as it shows up twice in any building, first in the bulb

electrical use and afterward on the heat dissipated by the bulb



Table 5 Building Ventilation requirements – VAV vs DOAS.

HVAC System VAV DOAS

Supply Air (m3/h) 180,000 180,000

Fresh Air required (m3/h) 158,400 86,400

Fresh Air Reduction Percentage – 46%


to space. In contrast to the ASHRAE baseline model, almost41.5% of savings in the use of entire-building are reached.

7.5. Modified energy model

Modified energy model comprising of a combination of effi-cient glazing, envelope insulation with modern LED lighting

fixtures, culminated in almost 55% savings in HVAC energyusage as shown in Fig. 16. Around 59% of Whole-BuildingEnergy’s energy savings contrasted with the ASHRAE baseline

model.

7.6. DOAS model

Implementing the DOAS to the Modified Energy model hasprovided the proper required ventilated conditioned outsideair to the healthcare building avoiding the mixing process inthe conventional VAV systems as appeared in Table 5.

Implementing DOAS to the Modified Energy Model actu-ally saves about 63.5% in HVAC use as Fig. 17. About 62%of DOAS model energy saved in entire building energy use rel-

ative to ASHRAE Baseline. This can be compared to theNREL Technical Report’s proposed savings of about 62%[41].

The baseline model for ASHRAE, the Modified EnergyModel, and the DOAS model are then compared to the initialmodel which shows the effect of different parameters on the

Fig. 15 LED Model Monthly Energy Analysis (MWh).

Fig. 16 Modified Energy Model Monthly Energy Analysis

(MWh).


energy use of HVAC and overall energy use as shown inFig. 18.

The energy demand for the Initial model, ASHRAE Base-

line model, Modified Energy, and DOAS models are shownin Fig. 19.

7.7. Thermal comfort

ASHRAE defines the thermal comfort as the ‘‘condition ofmind that expresses satisfaction with the thermal environ-

ment”, while the predicted mean vote as the judge of thermalcomfort scaled as following: +3 hot, +2 warm, +1 slightlywarm, 0 neutral, �1 slightly cool, �2 cool and �3 cold) [42].

The hospital thermal comfort simulation shows the tempera-ture, relative humidity and PMV intervals in Fig. 20.

Fig. 20 illustrates that the air temperature and relativehumidity were fluctuating between the recommended range

Fig. 18 Various Models Energy Utilization (MWh).

Fig. 17 DOAS Model Monthly Energy Analysis (MWh).



Fig. 19 Whole Building Energy Use Performance of Different

Models (MWh).


by both ASHRAE standards [34,42]. It also showed the PMVinterval through different months revealing that occupantsduring winter may feel slightly hot while they feel slightly cool

in summer.

Fig. 20 Hospital Therma

Table 6 Energy savings from HVAC opposed to the initial model.

Floor Initial model ASHRAE Baseli

Ground (MWh/year) 519 400

Floor 1 (MWh/year) 395 256




Total (MWh/year) 2777 2078

Cost (USD/Year) 333,240 249,360

Savings – 25%


7.8. Energy use and economical study

Energy use, initial costs, and running costs will be decided tobe used in the economical study.

7.8.1. Annual HVAC energy use

The operating cost of the study shown in Table 6 is estimatedbased on the latest global electricity tariff of business and com-mercial sector (0.12 USD/kWh).

7.8.2. Annual whole building energy use

Table 7 below shows a comparison of Whole Building EnergySavings of the different models.

7.8.3. CO2 emissions reduction

The reduction of energy contributes to reducing CO2 output,man-made global warming, and environmental pollution.

The United States Environmental Protection Agency [43],states that 1 kWh of energy consumption is responsible for

l Comfort Simulation.

ne model Modified Energy model DOAS model

215 177

150 117

173 153

192 149

208 164

938 760

112,560 91,200

66% 72.6%



Table 7 Entire energy savings relative to the initial model.

Floor Initial model ASHRAE Baseline model Modified Energy model DOAS model

Ground (MWh/year) 1329 1210 632 593

Floor 1 (MWh/year) 1053 914 343 310

Floor 2 (MWh/year) 1533 1430 462 442

Floor 3 (MWh/year) 1005 840 360 316

Floor 4 (MWh/year) 1037 864 375 331

Total (MWh/year) 5957 5258 2172 1992

Cost (USD/Year) 714,840 630,960 260,640 239,040

Savings – 12% 63% 67%

Table 8 Mitigation of CO2 emissions relative to the initial model.

Initial model ASHRAE Baseline model Modified Energy model DOAS model

Tons of CO2 4212 3718 1536 1409

Reduction – 12% 63% 67%

Table 9 Investments compared to Initial model.

Modification Area (m2) Increased Cost

(USD/m2)

Cost (USD)

Double Glazing 990 16 15,840

Walls Insulation 2310 7.2 16,632

Roof Insulation 1989 25 49,725

LED – – 138,228

Total Cost – – 220,425

Table 11 Cost comparison of Initial and DOAS models.

Model HVAC System Initial

Cost (USD)

Building Running Cost

(USD/Year)

Initial

Model

2,616,204 558,468

DOAS

Model

1,274,482 186,750


producing 0.707 kg of CO2, or 0.000707 tons of CO2. Com-pared with the initial model, Table 8 shows a reduction in

CO2 emissions across various models.

7.8.4. Economical study

This section presents an economical study associated with

building modifications and HVAC system implementation.The study covers the initial costs and the operating costs ofthe different models. The economic study is done to help

designers selecting an effective HVAC system that fulfills theventilation requirements and the cooling load of hospitalslocated in Alexandria, Egypt.

The cost analysis is based on the U.S. Department ofEnergy financing strategy [44].

Table 9 shows the investment which is the increased cost inUSD (1 USD = 16 L.E) between the initial model and the

Modified models based on the latest Egyptian market pricessurvey.

The results of the calculation are then tabulated in Table 10,

that the higher IRR and ROI means higher profitable invest-

Table 10 Economical Study Results.

Modification Payback Period

(Months)

Internal Rateof Retur

(IRR)

Glazing Model 16 72%

Insulation Model 19 60%

LED Model 6 172%

Modified Energy

Model

7 151%


ment. The combination of different parameters is the ModifiedEnergy Model.

The Initial cost of the Initial model is compared to the

DOAS model cost and tabulated in Table 11 according tothe latest Egyptian market prices in 2019. The HVAC system’sinitial cost in both models was estimated by the same consul-tant. The Running cost of both models is estimated based on

the latest global electricity tariff of business and commercialsector (0.12 USD/kWh) and is tabulated in the same table.

8. Conclusion

The analysis reveals that introducing energy-saving strategiesto medical institutions strengthens the efficiency of artificial

lighting fixtures, HVAC systems, and the overall use of build-ing energy; thus, reducing CO2 emissions. The findings are out-lined as:

� Pursuing ASHRAE weather recommendations (Alexandria,Egypt) results in a 30% lower cooling load relative to most

n Annual Return on Investment

(ROI)

Net Present Value

(USD)

47% 57,909

39% 191,578

112% 1,409,084

99% 1,953,447



Table A2 Occupant densities and plug loads recommended

for hospitals.

Zone Occupant Density

(#/100 m2) [32,33]

Plug Loads

(W/m2)

[36,37]

Ground Floor

Trauma 5.38 43.06

Triage 5.38 21.53

Examination/Treatment 5.38 16.15

Staff Lounge 66.67 1.00

Offices 7.53 11.84

Imaging Diagnosing Rooms 5.38 107.64

IT Room 4 10.00

Corridor/Waiting Area 32.29 1.08

Pharmacy 10.76 10.80

Shop 8 15.00

1st Floor

Clinics 5.38 16.15

Conference room 50 10.00

Treatment Rooms 5.38 16.15

Sampling/Laboratories 5.38 43.06

Offices 7.53 11.84


Egyptian market trends which certainly contribute to right-

sizing preventing oversizing of HVAC units.� ASHRAE Guidelines (Climatic Conditions, Ventilation,HVAC System, etc.) are recommended to be adapted to

the Egyptian sector as explored in this analysis observinga reduction of 25% in HVAC energy and around 12% inall-building energy utilization opposed to the Initial Model.

� Double glazing is a necessary parameter since the study

reveals around 5% savings in HVAC energy consumptionand approximately 2% in energy consumption in the wholebuilding.

� Building codes should be extended to all commercial prop-erties, such as the insulated envelope, as it revealed around16. 5% energy savings in the use of HVAC resources and

around 7% energy savings in total energy consumption inbuildings relative to the ASHRAE Baseline model.

� Nowadays, LEDs are energy-efficient, as they show areduction of about 21% in HVAC energy, while overall

energy consumption shows around 42% reduction in con-trast with the ASHRAE Baseline Model.

� In the assessment of energy-efficiency technologies, the

Modified energy model saves dramatically 55% in HVACusage and nearly 59% reduction of energy use across theentire building at 217 kWh/m2 as opposed to 525 kWh/m2

in the baseline model of ASHRAE and 596 kWh/m2 inthe initial model.

� Through introducing DOAS to the Modified Energy Model

a 67% decrease in Whole Building energy use can beaccomplished relative to the initial model.

� The annual EUI of the DOAS model is 199 kWh/m2

likened to ASHRAE 189.1 prescribed 200 kWh/m2 [17].

� The initial cost of the HVAC system has been nearlyhalved.

Table A1 Conditioned Area Percentage.

Zone Area (m2) Area %

Trauma 46 0.54%

Triage 16 0.19%

Examination/Treatment 301 3.55%

Staff Lounge 131 1.54%

Offices 243 2.86%

Imaging Diagnosing Rooms 228 2.68%

IT Room 50 0.60%

Corridor/Waiting Area 3774 44.30%

Pharmacy 68 0.80%

Shop 27 0.32%

Clinics 331 3.89%

Conference room 130 1.53%

Sampling/Laboratories 48 0.57%

Physical Therapy 133 1.56%

Operating Rooms 351 4.12%

Delivery Rooms 32 0.38%

Recovery Rooms 83 0.98%

Post-Surgery Rooms 37 0.44%

NICU 129 1.52%

ICU 226 2.66%

Bedwards 1728 20.20%

Living Rooms 248 2.92%

Isolation Rooms 58 0.69%

Doctors Rooms 99 1.18%

Total Conditioned Area 8517 100%


� Energy-saving techniques help and support reduce green-

house gas emissions, leading to environmentalconservation.

Energy-efficiency in commercial buildings have a significantimpact on both initial HVAC costs and the entire buildingenergy consumption. Egypt’s policymakers should, therefore,consider implementing the energy code to establish minimum

energy performance levels for buildings under constructionand retrofitting of existing buildings that eventually leads tolower energy consumption and fuel consumption.

IT Room 4 10.00

Physical Therapy 10.76 10.80


Imaging Diagnosing Rooms 5.38 107.64

2nd Floor

Operating Rooms 5.38 43.06

Delivery Rooms 5.38 43.06

Recovery Rooms 5.38 21.53

Post-Surgery Rooms 5.38 21.53

NICU 5.38 21.53

ICU 5.38 21.53

IT Room 4 10.00

Offices 7.53 11.84


3rd Floor

Bedwards 5.38 10.80

Living Rooms 5.38 10.80

Isolation Rooms 5.38 43.06

Doctors Rooms 5.38 10.80


IT Room 4 10.00


4th Floor

Bedwards 5.38 10.80

Living Rooms 5.38 10.80

Isolation Rooms 5.38 43.06

Doctors Rooms 5.38 10.80


IT Room 4 10.00




Fig. A1 Hosp

Table A3 Equipment Specifications.

System Type

Cooling Equipment Two air cooled chillers 393TOR/Each

Fan Coil Units Quantity 480

Air Handling Units Quantity 20

Fresh Air Handling Unit Quantity 1



Funding

This research did not receive any specific grants from fundingagencies in the public, commercial, or no-profit sectors.

Declaration of Competing Interest

The authors declare that they have no known competingfinancial interests or personal relationships that could haveappeared to influence the work reported in this paper.

ital Plans.




Appendix A. See Tables A1–A3 and Fig. A1.

References

[1] Egyptian Electricity Holding Company annual report 2017/

2018.

[2] Advanced Energy Design Guide for Large Hospitals: 50%

Energy Saving, ASHRAE 2012.

[3] U.S Energy information administration (EIA), International

energy data and analysis, 2019.

[4] M.A. Sohoo, Design, Evaluation and Techno-Economic

Analysis of a Demand Controlled Ventilation in Hot and

Humid Climate (Doctoral dissertation, The British University in

Dubai (BUiD)), 2015.

[5] E. Khalil, Energy efficient design and performance of

commercial buildings in developing countries, The Second

International Energy 2030 Conference, Abu Dhabi, 2008.

[6] M. Krarti, Energy audit of building systems, second ed.

[7] W.F.M. Yusoff, S. Mirrahimi, M.F. Mohamed, L.C. Haw, The

effect of building envelope on the thermal comfort and energy

saving for high-rise buildings in hot–humid climate, Renew.

Sustain. Energy Rev. J. 53 (2016) 1508–1519.

[8] H.M. Karmany, Evaluation of Green Building Rating Systems

for Egypt, American University in Cairo, 2016, Thesis.

[9] A. Gonzalez, J.G.S. Calcedo, D.R. Salgado, A quantitative

analysis of final energy consumption in hospitals in Spain,

Sustain. Cities Soc. J. 36 (2018) 169–175.

[10] A. Dutta, A. Samanta, Reducing cooling load of buildings in the

tropical climate through window glazing, J. Build. Eng. 15

(2018) 318–327.

[11] B. Ahn, C. Jang, S. Yoo, H. Jeong, Effect of LED lighting on

the cooling and heating loads in office buildings, Appl. Energy J.

113 (2014) 1484–1489.

[12] D. Jenkins, M. Newborough, An approach for estimating the

carbon emissions associated with office lighting with a daylight

contribution, Appl. Energy J. 84 (2007) 608–622.

[13] A. Sabry, M. Ibrahim, E. Khalil, Energy performance

simulation in residential buildings, Procedia Eng. J. 205 (2017)

4187–4194.

[14] M.A. William, A.M. El-Haridi, A.A. Hanafy, A.E. El-Sayed,

Assessing the Energy Efficiency improvement for hospitals in

Egypt using building simulation modeling, ERJ Eng. Res. J. 42

(1) (2019) 21–34.

[15] A. Elharidi, P.G. Tuohy, M.A. Teamah, The energy and indoor

environmental performance of Egyptian Offices, Energy Build.

J. 158 (2017) 431–452.

[16] T.M. AbdulRazek, Key Performance Indicators of Energy

Efficiency for Small and Medium Enterprises, Kassel

University, Germany, 2014, Thesis.

[17] Ministry of Economy, Estrategia de Ahorro y Eficiencia

Energetica en Espana 2004–2012 en el sector de la edificacion,

2003.

[18] A. Carbonaria, R. Fiorettib, M. Lemmaa, P. Principi, Managing

energy retrofit of acute hospitals and community clinics through

EPC contracting: the MARTE project, Energy Procedia (2015).

[19] T. Hoyt, E. Arens, H. Zhang, Extending air temperature

setpoints: simulated energy savings and design considerations

for new and retrofit buildings, Build. Environ. J. 88 (2015) 89–

96.

[20] P.E. Farhad Memarzadeh, A.P. Manning, Comparison of

Operating Room Ventilation Systems in the Protection of the

Surgical Site.

[21] Attia A el Hamid, M. El Helw, H.A. Teamah, Three-

dimensional thermal comfort analysis for hospital operating

room with the effect of door gradually opened, CFD Lett. 1

(2013) 5.


[22] Z. Zhanga, X. Caoa, Z. Yanga, L. Shaoa, C. Zhanga, A new

dedicated outdoor air system with exhaust air heat recovery,

12th IEA Heat Pump Conference, 2017.

[23] H. Kim, S. Lee, S. Cho, J. Jeong, Energy benefit of a dedicated

outdoor air system over a desiccant-enhanced evaporative air

conditioner, Appl. Therm. Eng. (2016).

[24] William M, El-Haridi A, Hanafy A, El-Sayed A. Assessing the

energy efficiency and environmental impact of an egyptian

hospital building. In: IOP Conference Series: Earth and

Environmental Science 2019 Nov, Vol. 397, No. 1, IOP

Publishing, pp. 012006.

[25] Carrier System Design Manual Handbook.

[26] ASHRAE Handbook of Fundamentals, American Society of

Heating, Refrigerating and Air Conditioning Engineers Inc.,

2017.

[27] EnergyPlus, National Renewable Energy Laboratory (NREL),

U.S. Department of Energy, Building Technologies Office

(BTO).

[28] ASHRAE Guide for Buildings in Hot and Humid Climates,

second ed.

[29] Excellence in Design for Greater Efficiencies (EDGE) Energy

Management Handbook, International Finance Corporation,

2017.

[30] Egyptian Heat Insulation Works Code, Housing and Building

National Research Centre (HBRC), Egyptian Ministry of

Housing, 2007.

[31] CIBSE Guide for Energy Efficiency in Buildings, UK.

[32] AIA Guidelines for Design and Construction of Hospitals and

Health Care Facilities, American Institution of Architects

Washington, D.C., 2006.

[33] ASHRAE, Ventilation for Acceptable Indoor Air Quality,

ANSI/ASHRAE Standard 62.1-2016, American Society of


Atlanta, GA, 2016.

[34] ASHRAE, Ventilation of Healthcare Facilities, ANSI/

ASHRAE/ASHE Standard 170-2017, American Society of


Atlanta, GA, 2017.

[35] Y. Miyaoka, H. Nakayama, Y. Teranishi, N. Yoshizawa, N.

Kabashima, M. Hirota, Influence of LED bulbs on air-

conditioning load and energy consumption in commercial

buildings, 12th IEA Heat Pump Conference, 2017.

[36] GGHC, Green Guide for Health Care: Best Practices for

Creating High-Performance Healing Environments, Version

2.2, 2007.

[37] ASHRAE, Energy Standard for Buildings Except Low-Rise

Residential Buildings, ANSI/ASHRAE/IESNA Standard 90.1-

2016. American Society of Heating, Refrigerating and Air

Conditioning Engineers, Atlanta, GA, 2016.

[38] S.A. Mumma, Understanding and Designing Dedicated

Outdoor Air System (DOAS), 2010 Mar.

[39] A.F. Radwan, A.A. Hanafy, M. Elhelw, A.E. El-Sayed,

Retrofitting of existing buildings to achieve better energy-

efficiency in commercial building case study: hospital in Egypt,

Alexandria Eng. J. 55 (4) (2016) 3061–3071.

[40] Strategy Guideline: Accurate Heating and Cooling Load

Calculations, Office of Energy Efficiency and Renewable

Energy, U.S. Department of Energy’s Building Technologies

Office (BTO).

[41] National Renewable Energy Laboratory (NREL), U.S.

Department of Energy Technical Support Document, Large

Hospital 50% Energy Savings.

[42] ASHRAE, ANSI. ASHRAE 55: 2017 Thermal Environmental

Conditions for Human Occupancy. ASHRAE Standard, 2017.

[43] U.S Environmental Protection Agency, – EPA, 2017.

[44] Financing for Energy & Sustainability, U.S Department of

Energy.


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