Solar Air Conditioning Research Paper (Final)

8/13/2019 Solar Air Conditioning Research Paper (Final)

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SCHOOL OF ENGINEERING

EM306

THEMODYNAMIC II Group Research Assignment

Name ID Number Course

Prabu Gunasagaran 1001027982 Mechanical EngineeringNikthian Mony 1000820310 Mechanical EngineeringSyed Ali Mohsenian 1000923912 Mechanical Engineering


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Table of Contents

No. Description Page1 Introduction 1

2 1.0 Thermodynamics properties used in the system

1.1 Thermodynamic Analysis of the Solar AbsorptionCooling system

1.1.2 Absorbents

1.1.3 Refrigerant-absorbent combinations

1.2 Adsorption Cooling Method

1.3 Desiccant cooling system

2 - 4

4 - 6

6

6

6 - 9

9 - 11

3 2.0 Specific Devices and availability in the market 11 - 17

4 3.0 Introduction to potential improvement 17 - 26

5 4.0 Potential to society, economic, geographic conditions, and

consideration for successful commercial implementation in

Malaysia

26 - 31

6 References 33 - 35


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Introduction

Today, renewable energies supply 14% of the world primary energy demand. These

renewable energies include biomass, hydro and other renewables. Other renewables include solar,

wind, tidal, geothermal and wave energy and are approximately 1% of the world primary energydemand. However, the utilization of these other renewables is increasing faster (5.7% annually)

than other primary energy sources (International Energy Agency (IEA), 2004). Threats of climate

change, exhaustion of fossil fuels and the need for secure energy supply stimulate the utilization

of renewable energies. In short, today s global energy system is unsustainable in economic, social

and environmental terms. In the near term renewable energies may be a solution for the problems

mentioned above although they have some drawbacks.

This assignment project discusses on the feasibility, sustainability and potential ofimplementing the solar air conditioning for Malaysia. This assignment will cover the following

topics which are Use of thermodynamics principles for the system, specific devices, equipment in

market or in development, Potential improvements or alternatives available, potential to the social,

economic, and geographic condition in Malaysia and consideration for the successful commercial

introduction of solar air conditioning in Malaysia based on existing research journals and

development obtained from relevant and reliable sources.


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1.0 Thermodynamics properties used in the system .

The first topic of coverage is on thermodynamics properties used in the system. The

demand for thermal air-conditioning is increasing the annual energy use of room air conditioner

was about 1.7 GW h in 1990 and is estimated to reach 44 GW h in 2010. Solar heating and air-

conditioning is one possible way to reduce building fossil fuel consumption and greenhouse gas

emission in low-energy buildings. Three technologies are available for solar heat-driven air-

conditioning which are absorption, adsorption and desiccant cooling. Among these technologies,

absorption is the most widely used with 59% of the installed systems in Europe against 11% for

adsorption and 23% for desiccant cooling.

Adsorption chillers have lower COP than absorption ones but can work at lower driving

temperature. Different heat-driven cooling technologies are available on the market at capacities

above 40 kW. However, the use of smaller scale systems in the residential/building sector implies

further research and development work as nearly none of the mentioned technologies is available

on the market at these small capacities.

There are many thermodynamic analysis that have been performed on this 3 forms of technologies.

The most widely researched method is the absorption system and this system is classified into 2

categories which is intermittent and continuous. Both of these types include four basic componentswhich are; generator, condenser, evaporator and absorber.

The intermittent type consist of two major operations which is the regeneration and refrigeration.

In the regeneration process, the refrigerant-absorbent solution is heated to drive the refrigerant

vapor off the solution. The necessary heat can be provided by the use of solar collectors (flat-plate,

cylindrical, or any other kind depending on the temperature range needed). Traveling from the

generator into the condenser, the refrigerant vapor is condensed and stored. Then, the refrigeration

process takes place during which the liquid refrigerant vaporizes and produces a cooling effect inthe evaporator, whereas the refrigerant vapor is re-absorbed by the absorbent (solvent) in the

absorber. These two operations occur one after another and the cooling effect is therefore

discontinuously produced and therefore the name intermittent. This method was the earlier

methods developed and was a less effective cooling method than the continuous cooling method


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as air-conditioning is generally needed in a continuous fashion. Therefore, the continuous cooling

absorption cycle was developed.

In a continuous absorption cycle, refrigeration and regeneration processes; occur at the same time

and a continuous cooling effect is produced. The flow diagram is shown by Figure 1. Weather

conditions such as insulation ambient temperature are important factors in a solar heating and

cooling system design. Performance of solar systems may change during the day and be different

between a clear day and a cloudy day. Due to these factors and the lack of solar energy at night,

consideration of a storage unit for any continuous solar utilization system is essential. The solar

heat is added to the generator for the purpose of continuous vaporization of the refrigerant from

the solution. After the vapor refrigerant and the solar energy input to the collector refrigerant passes

through the condenser heat is removed from the refrigerant vapor and the pure refrigerant isliquefied. The liquid refrigerant then goes through an expansion valve into the evaporator wherein

cooling is achieved by continuous vaporization of the refrigerant at low temperature. The

vaporized refrigerant is then dissolved in the weak refrigerant-solvent solution present in the

absorber which forms a strong refrigerant solution. This rich solution is then pumped back into the

generator through a small liquid pump and the cycle continues. Since the recombination of the

refrigerant with the solvent in the absorber is exothermic, heat must be removed from the absorber

in order to maintain a sufficiently low temperature so that a high chemical affinity between the

refrigerant and the weak solution can be assured. For the operation of an absorption cycle, cooling

water (or air) used in the condenser and absorber should be at room temperature (or at any other

available heat sink temperature). The pressure in the absorber which is equivalent to the pressure

in the evaporator and the concentration of refrigerant in the absorber determine the temperature of

the absorber. For an ideal absorption cycle, the refrigerant should be liquefied at its saturation

temperature in the condenser. Therefore, the temperature of the condenser depends on its pressure.

The generator pressure, which is identical to the condenser pressure, and the concentration of the

refrigerant in the generator determine the minimum temperature of the generator which has to bemaintained for the continuous vaporization of the refrigerant. Theoretically, the refrigerant

concentration in the generator must be less than that in the absorber. In principle, four factors are

considered, evaporator temperature, condenser temperature, and the concentrations of the

refrigerant in the generator, and absorber, will determine the operating conditions of an ideal


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absorption cooling cycle. In an actual absorption cycle there exists a heat exchanger (economizer)

between the generator and absorber for the purpose of recovery of heat in the flow from generator

to absorber and preheating of the flow from absorber to generator. In certain cases of absorber

cooling cycles, there may exist a secondary generator for a better separation of refrigerant and

absorbent.

Figure 1: Example of an absorption cooling cycle

The absorption technique uses the following combinations of working fluid as refrigerant-

absorbent mixtures as the following NH3+H20, NH3+NaSCN, and H2O+LiBr combination which

are the favorable candidates used in the solar absorption cooling cycle.

1.1 Thermodynamic Analysis of the Solar Absorption Cooling system

The coefficient performance (COP) of an absorption cooling system is defined as the ratio of

cooling effect by the evaporator and the solar energy input to the collector is defined by:.

( ) = | | / | |


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between the compounds which qualify as refrigerants for absorption solar cooling systems. H20

and NH3 have relative1y high heats of vaporization per unit mass around atmospheric pressure.

1.1.2 Absorbents

In screening of absorbents for absorption solar cooing systems stability, toxicity, corrosivity and

mutual Solubility with refrigerant, should be considered as the criteria. The criteria for selection

of absorbents should be the boiling point and melting point of the candidate. Generally normal

boiling points above 100 C should satisfy the low volatility requirement of the absorbents. Criteria

for maximum melting point of absorbent allowable depends on the crystallization possibility of

the absorbent. However, some absorbents form eutectic solutions with the refrigerants even with

temperatures below the melting point of the absorbent.

1.1.3 Refrigerant-absorbent combinations

The combination of a refrigerant and an absorbent should have the following characteristics in

order to qualify for use in absorption solar cooling systems: (i) Equilibrium solubility should be

high at the required temperature and pressure in the absorber. (ii) Absorption should be rapid and

the actual concentration of rich liquid should easily approach the equilibrium value. (iii) Pure

refrigerant vapor should be obtained from rich solution as easily as possible. (iv) The absorbent

should be non-volatile or (very much less volatile than the refrigerant). (v) The viscosities of

solutions should low under operating conditions. (vi) Freezing points of liquids should be lower

than the lowest temperature the cycle.

1.2 Adsorption Cooling Method

The adsorption cooling process utilizes the adsorbent-adsorbate characteristics and

produces cooling at the evaporator by t he combination of adsorption -triggered evaporation and

desorpti on-resulted- condensation. Figure 2 shows the schematic layout of the adsorption cooling

system that comprises the evaporator, the reactor or bed for thermal compression and the

condenser. Usually, activated carbon fiber and CO2 are used as adsorbents and refrigerant. For


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continuous cooling operation, firstly a low-pressure refrigerant (hence CO2) is vaporized at the

evaporator due to external cooling load and is adsorbed into the solid adsorbent located in the

adsorber at evaporator pressure (Pe). The process of adsorption results in the liberation of heat of

adsorption at the adsorber providing a useful heat energy output and a cooling effect in the

condenser/evaporator heat exchanger. Secondly, the adsorbed bed is heated by the external heat

source and the refrigerant is desorbed from the adsorbent and goes to the condenser. At condenser

pressure (Pc) for condensation by pumping heat through the environment. The condensate

(refrigerant) is refluxed back to the evaporator via a pressure reducing valve for maintaining the

pressure difference between the condenser and the evaporator. Pool boiling is affected in the

evaporator by the vapor uptake at the adsorber, and thus completing the refrigeration close loop or

cycle.

Figure 2: Adsorbtion cooling cycle

As the adsorption cooling system is based on the energetic performances of adsorbant-refrigerant

pairs, the adsorption isotherms are used to evaluate the amount of adsorbate uptake and offtake

during adsorption/desorption processes.

To analyze the cycle, the cycle must be plotted on a Clapeyron Diagram. The various

characteristics could be obtained by the Clapeyron diagrams of the chemical heat pumps and it is

clearly be seen the isosteric and isothermic characteristics of the cycle. By plotting the sys tem s


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cycle along the equilibrium lines of the clapeyron diagram, the operating pressure, the range of

temperature upgrade, mass of the working pairs required, amount of power consumed and heat

released, etc. could be predicted.

Adsorption refrigeration cycle is not too much different from absorption refrigeration cycle. Itcontains mainly condenser, evaporator, expansion valve, adsorbent bed, some adsorbent and some

adsorbate. The main adsorbent and adsorbate pairs are Activated Carbon/Ammonia, Silica

gel/methanol, Silica gel/water and Zeolite/water. In this system the compressor is replaced by a

thermal compressor which is operated by heat instead of a mechanical energy.

In evaporator the adsorbate evaporates by having heat from surroundings. Adsorbate adsorbed by

the dry adsorbent in the adsorbent bed. The heat is transferred in to adsorbent bed for desorption.

The desorbed material continues cycling in to the condenser. After condensation adsorbateexpands in the expansion valve and arrives to evaporator. The ideal adsorption cooling cycle on a

schematic vapor pressure diagram is given in Figure 2.5.

Figure 2.5 schematic vapor pressure diagram


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In Figure 2.5, from point 1 to point 2 the adsorbent bed s temperature increases from T1 to T2

with transferring heat from outside in to the system. In preheating the vapor pressure is steady

without desorption. From point 2 to 3 the heat transfer to the adsorbent bed goes on. But in this

period from point 2 to 3, desorption begins and the desorbed water vapor condenses in steady

condensation pressure. Point 3 to 4 region begins after the maximum bed temperature reached and

desorption finished the bed temperature decreases to the T4. An expansion valve also helps the

pressure decrease. From 4 to 1 the heat transfer from bed to surroundings goes on. The adsorbate

that evaporates in the evaporator adsorbed by the adsorbent. This is a heat loosing process.

1.3 Desiccant cooling system

Desiccant cooling systems combine sorptive dehumidification, heat recovery, evaporation and

heating to create a cooling process which can offer energy savings compared to conventional airconditioning systems. Waste heat or solar energy can be used for the required regeneration of the

sorbens in the dehumidifier, leading to further energy savings. Parametric studies, particularly of

the dehumidifier, have been undertaken. These show that it may be possible to reduce the

regeneration air flow without a significant reduction in the dehumidification efficiency, enabling

desiccant cooling systems to run with high COPs. The results of the measurements were used as

input parameters for a new dynamic simulation program, which was specifically developed for the

purpose of assessing the potential for desiccant cooling under different climatic conditions.

Desiccant cooling system takes air from outside or from the building, dehumidifies it with a solid

or liquid desiccant, cools it by heat exchange and then evaporatively cools it to the desired state of

a maximum 100% relative humidity in the inlet air stream. The desiccant must be regenerated by

heat. This can be achieved with solar energy from solar air collectors or liquid collectors.


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Figure 3: Desiccant cooling system with solar air collectors.

Figure 3 shows how solar air collectors can be integrated. Adaptation to liquid collectors is also

possible with an air/liquid heat exchanger. By using solar liquid collectors the storage possibility

can increase the content of solar energy to the required auxiliary energy.

Figure 4 shows the process in a shematic, where the state points are numbered to correspond to the

points on the process schematic. Ambient air is dried and heated by a dehumidifier from 1 to 2,regeneratively cooled by exhaust air from 2 to 3, evaporatively cooled from 3 to 4 and then brought

into the building. The inlet humidifier allows control of the temperature and humidity. Exhaust air

at state 5 from the inside of the building moves in the opposite direction and is evaporatively

cooled to 6 up to saturation. At 7 the air is heated by the energy removed from the heat regenerator.

From 7 to 8 solar or other heat must increase the temperature up to the regeneration level of the

desiccant to regenerate the dehumidifier.


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Figure 4: Conditions of air in a desiccant cooling system. A bypass flow of 25% is considered.

With the existing knowledge of thermodynamics, the absorption cooling method seems a more

viable cooling method compared to the adsorbtion cooling method for residential use in Malaysia.

This is due to the abundance of the materials used are widely available in Malaysia which is also

used in other processes and products. Desiccant cooling is also a viable option as Malaysia a humid

country and the desiccant cooling method deals with levels of humidity. The adsorption method

may not be the best choice for residential purpose but it may be applied in a large scale for

industrial applications.

2.0 Specific Devices and availability in the market

This part describes few examples of devices / equipment in market such as heat driven cooling

technologies in combination with solar thermal energy. A short overview about solar refrigeration

systems is explained with a basic analysis of thermodynamic. Furthermore, new developments ofopen (desiccant cooling) and closed (absorption and adsorption) cooling cycles are presented and

some of the new technologies are demonstrated in more detail. Additionally, recent installations

of solar-thermal of air conditioning systems are described as examples with their working

performance and system description. This report also includes small scale solar thermal absorption

cooling system design in the following pages. The general purpose of the design is to understand


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how efficiently solar cooling system generates cooling, and to reduce the footprint of systems for

integration with existing and future domestic buildings

The energy use in the building sector for space heating, cooling and water heating, in the European

Union Based, reaches the level of on 40% of the total used energy. The building sector is the

biggest user of energy, having surpassed the transportation and industry sectors. Additionally, the

energy transformation processes and the use of energy are responsible for 94% of the total

emissions of CO 2, with 45% coming from the building sector. The applicability of solar cooling in

Greece was investigated in a medical centre in Igoumenitsa.

A transient simulation model were used to study the energy performance and economical

feasibility for integrating a solar liquid desiccant dehumidification system with a conventional

vapor compression air-conditioning system for the weather condition of Hong Kong. The vapor

compression system capacity in the solar assisted air-conditioning system can be reduced to 19 kW

from original 28 kW of a conventional air-conditioning system as a case study due to the solar

desiccant cooling.

How s a schematic diagram of a solar desiccant air-conditioning system. Ambient humid air enters

the supply air duct and passes through the packed type dehumidifier of the primary air handling

unit where it will be dehumidified and heated by dry desiccant. After exiting from the primary air

handling unit, the hot and dry air is then cooled by a cooling coil and then distributed to the room.


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Solar air conditioning systems consist of two components coupled together: thermal solar

collectors and an absorption system. This system is mainly driven by the dilution heat effect of the

aqueous lithium bromide and has the capability to get power from a low relative temperature and

dispose part of this heat at high relative temperature, by means of the heat pump. This

thermodynamic equilibrium process is based on a pressure gradient caused by the effect of

concentration or temperature. The weight concentration for air conditioning is defined as the

percentage ratio between the weight of lithium bromide and the total weight of the solution in the

system. This work proposes a method for measuring the concentration of corrosive liquids, which

can be applied to the development of an optical device for determining the fluid concentration in

solar air conditioning systems.

The overall efficiency depends on the temperature and concentration of the working fluid, as

shown in figure below 1, for different pressure conditions of the condenser and in each process of

the evaporator.

Fig. 1. Schematic diagram of a solar air conditioning system with temperature along the x-axis and

pressure along y-axis.

Active solar cooling uses solar thermal collectors to provide solar energy to thermally driven

chillers (usually adsorption or absorption chillers). The solar energy heats a fluid that provides
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heat to the generator of an absorption chiller and is recirculated back to the collectors. The heat

provided to the generator drives a cooling cycle that produces chilled water. The chilled water

produced is used for large commercial and industrial cooling.

The following are common technologies in use for solar thermal closed-loop absorption airconditioning.

NH3/H2O or Ammonia/Water

Water/Lithium Bromide

Water/Lithium Chloride

Water/Silica Gel or Water/Zeolite

Methanol/Activated Carbon

Solar thermal energy can be used to efficiently cool in the summer, and also heat domestic hot

water and buildings in the winter. Single, double or triple iterative absorption cooling cycles are

used in different solar-thermal-cooling system designs. The more cycles, the more efficient they

are. Absorption chillers operate with less noise and vibration than compressor-based chillers.

In large scale installations there are several projects successful both technical and economical in

operation world wide including, for example, in Lisbon with 1,579 square metres (17,000 sq ft)

solar collectors and 545 kW cooling power or on the Olympic Sailing Village in Qingdao, China.

In 2011 the most powerful plant at Singapore's newly constructed United World College will be

commissioned (1500 kW).These projects have shown that flat plate solar collectors specially

developed for temperatures over 200 F (93 C) can be effective and cost efficient.

The Audubon Environmental Center in Los Angeles has an example solar air conditioning

installation. which failed fairly soon after commissioning and is no longer being

maintained [9] The Southern California Gas Co. Some Gas Company is also testing the practicality

solar thermal closed-loop absorption air conditioning at their Energy Resource Center (ERC) in

Downey, California. Solar Collectors from Sopogy and Cogenra were installed on the rooftop at

the ERC and are producing cooling for the bui ldings air conditioning system Masdar City in

the United Arab Emirates is also testing a double-effect absorption cooling plant
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using Sopogy parabolic trough collectors, Mirroxx Fresnel array and TVP Solar high-vacuum

solar thermal panels.

The ISAAC Solar Icemaker is an intermittent solar ammonia-water absorption cycle. The ISAAC

uses a parabolic trough solar collector and a compact and efficient design to produce ice with nofuel or electric input, and with no moving parts.

Providers of solar cooling systems include SOLID, Sopogy ,] Cogenra Mirroxx and TVP Solar for

commercial installations and ClimateWell, Fagor -Rotartica, SorTech and Daikin mostly for

residential systems. Cogenra uses solar co-generation to produce both thermal and electric energy

that can be used for cooling.

The very latest solar air conditioning technology

Above is an exampla of Australian commercial solar air condition. Also known as Solar cooling

is a term that encompasses a range of technologies designed to utilise a solar thermal input

(typically very hot water) to delivery cool air into a building. The suns heat can be turned into

cool air via a number of different thermodynamic reactions, resulting in cooling with minimal

electrical input.
http://en.wikipedia.org/wiki/Sopogyhttp://en.wikipedia.org/wiki/Parabolic_troughhttp://en.wikipedia.org/wiki/Solar_thermal_collectorhttp://en.wikipedia.org/wiki/Sopogyhttp://en.wikipedia.org/wiki/Solar_air_conditioning#cite_note-18http://en.wikipedia.org/wiki/Solar_air_conditioning#cite_note-18http://en.wikipedia.org/wiki/Solar_air_conditioning#cite_note-18http://en.wikipedia.org/w/index.php?title=Mirroxx&action=edit&redlink=1http://en.wikipedia.org/wiki/ClimateWellhttp://en.wikipedia.org/wiki/Fagorhttp://en.wikipedia.org/w/index.php?title=Rotartica&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=SorTech&action=edit&redlink=1http://en.wikipedia.org/wiki/Daikinhttp://en.wikipedia.org/wiki/Daikinhttp://en.wikipedia.org/w/index.php?title=SorTech&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Rotartica&action=edit&redlink=1http://en.wikipedia.org/wiki/Fagorhttp://en.wikipedia.org/wiki/ClimateWellhttp://en.wikipedia.org/w/index.php?title=Mirroxx&action=edit&redlink=1http://en.wikipedia.org/wiki/Solar_air_conditioning#cite_note-18http://en.wikipedia.org/wiki/Sopogyhttp://en.wikipedia.org/wiki/Solar_thermal_collectorhttp://en.wikipedia.org/wiki/Parabolic_troughhttp://en.wikipedia.org/wiki/Sopogy


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Two main types of solar cooling and low energy cooling technologies:

Absorption and Adsorption based chiller systems

These thermal cooling systems utilize well-known thermodynamic processes to deliver chilled

water that can be adapted for cooling applications, both large and small. These systems can utilize

solar thermal heat, waste heat, supplemental heat, or a combination of all three.

Absorption and Adsorption chillers are well known for their longevity and low maintenance

requirements. And by storing solar heated water in tanks, they can even deliver solar cooling after

the sun goes down.

We offer a range of sorption chiller systems, including specialist units that are capable of delivering

temperatures below freezing for low-energy refrigeration purposes.


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3.0 Introduction to potential improvement

Energy efficiency has become universally recognized as one of the most cost-effective ways of

enhancing energy security, addressing climate change and promoting competitiveness in industry.

Improving efficiency is perceived as the key strategy in making the worlds energy system more

economically and environmentally maintainable. Potential improvements exist in all economies across all

areas; at home, in factories, office buildings, airports, shopping malls, power plants, etc.

While the industry has flourished in some countries, it has had difficulty taking off in others.

Despite government efforts to introduce Energy efficiency related targets and regulations, progress in the

development of the Energy efficiency industry in Southeast Asia remains sporadic. The study focuses on

Singapore, Malaysia, Indonesia, Thailand and Vietnam. Taken together, these five countries accounted for

86% of ASEANs total GDP in 2010, and present a sizeable market for Energy efficiency te chnologies and

products.


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The study seeks to estimate the size of the potential Energy efficiency improvements in the region

in terms of potential power savings from the user perspective. It also outlines in detail the barriers to the

continuous development of the Energy efficiency market based on the results of stakeholder interviews and

surveys, and proposes solutions to address these barriers in order to unlock the full potential of the regional

Energy efficiency improvements.

The study is based on survey questionnaires and face-to-face interviews with a diverse portfolio of

companies, including Energy efficiency technology suppliers, ESCOs, and Energy efficiency product users.

These included both European and non-European companies, spanning many industries including

chemicals, energy generation & distribution, food & beverage, logistics, pharmaceuticals, property

management and steel manufacturing. Several government agencies, financial institutions and academic

institutes were also interviewed to obtain their perspectives on the Energy efficiency issue in Southeast

Asia.

This document can hopefully serve as a broad guide on a possible way forward for key stakeholders

in the Energy efficiency industry in the region.

Southeast Asia is a resource-rich region the region as a whole has been a key exporter of oil, natural

gas and coal. Indonesia was the worlds second largest coal exporter in 2010 3. Vietnam is home to the

worlds largest gas pipeline in terms of combined gas and liquids flow 4, while Malaysia w as the worlds

third largest LNG exporter in 2010. 5 Countries in the region mainly rely on oil, natural gas and coal as their

energy and power sources, with minor contributions from hydro-electric, renewable and geothermal

sources.

In 2009, the IEA forecasted that Southeast Asia will become a key global energy market and future

growth driver. The regions steadily growing economy is expected to lead to its energy and power

consumption almost doubling between 2010 and 2020. Over the next few decades, the region is expected

to witness an exponential increase in energy demand, energy related investments and spending.

Improvements in annual energy outputs of over 9% are possible in some parts of the world. The best

performing areas are largely based the tropics. This is encouraging as solar energy already performs well

in these areas and enhanced cooling. could increase cost-effectiveness.


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The vital need of cooled air and air conditioners In the ASEAN region is as we have discussed is a very

important aspect as the countries are demanding more and more units as the economy is growing, we all

know that the fossil fuels are running out and they are not as efficient as we want them to be, to run the A/C

we need electricity in this time witch for the time being we are receiving this by fossil fuels and non-

renewable power, the potential of new technology is there and that is solar power solar power is free, long

lasting and environmental friendly, we come to a conclusion that we have to change the approach of energy

making as this is our only way for a better safer future.

Solar air-conditioning is envisioned as a sustainable mean to provide space conditioning for buildings,

as solar energy is considered to be the primary energy source. Solar air-conditioning is broadly categorized

into solar-electric air-conditioning and solar-thermal air-conditioning. The former mainly covers the solar-

electric compression refrigeration, which uses photovoltaic panels to power up a conventional refrigeration

machine. The latter makes use of the solar thermal gain to drive the corresponding heat-driven cycle. The

solar absorption refrigeration, the solar adsorption refrigeration and the desiccant cooling belong to solar-

thermal air-conditioning. Through dynamic plant and building simulation for typical office in subtropical

climate, the solar-electric compression refrigeration and the solar absorption refrigeration can have the year-

round primary energy saving compared to the conventional electric-driven compression refrigeration. On

the other hand, the solid desiccant cooling, which is commonly designed for full air provision, can also

have the energy saving potential comparatively. To further advance the energy performance of the solar

air-conditioning systems, different design strategies can be considered, such as the hybrid design between

absorption/adsorption refrigeration and desiccant cooling, the high temperature cooling approach using

radiant ceilings, and the articulation to the new indoor ventilation mean like displacement/stratum

ventilation. These strategies can enhance better use of solar thermal gain and reduce auxiliary heating. As


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such, the solar air-conditioning systems would become more and more competitive in terms of year-round

energy performance.


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A simple figure can illustrate how a solar panel is prepared

The energy flows in and out of each layer are calculated. This can be used to determine the temperature of

each layer of the solar panel. The temperature of the solar cell layer dictates the electrical efficiency of the panel; for each C increase efficiency decreases by 0.45%. Electrical output is then calculated by

Power output = Efficiency Sunlight intensity

and this is summed over one year of performance using sunlight intensity, air temperature and wind speed

data available from climate models. The same calculation is performed for a solar panel with no phase

change material attached to determine the percentage output improvement.

Technologies for solar-driven cooling and air conditioning, a dialogue of solar cooling technologies is given

in. The article by Grossman presents an overview of solar cooling, including thermodynamic

considerations. The manual by Henning also includes practical design aspects. The systems under

consideration are generally divided into two main categories closed and open cycles.

Closed-cycle systems these types of systems are based mainly on the absorption cycle, which constitutes,

thermodynamically, of a heat engine driving a heat pump. In its simplest, single- effect conguration, an


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absorption system employs a refrigerant expanding from a condenser to an evaporator through a throttle, in

much the same way as in the conventional vapor compression system. A second working uid the

absorbent is employed, which absorbs refrigerant vapor from the evaporator at low pressure, and desorbs

into the condenser at high pressure, when heat is supplied to the desorbed. The absorption system is hence

a heat-driven heat pump; the heat may come from a variety of sources, including solar, waste heat and the

like. The system operates between two pressure levels, and interacts with heat sources/sinks at three

temperature levels: The low temperature cooling in the evaporator the intermediate temperature heat

rejection in the absorber and condenser; and the high temperature (solar) heat supply in the desorbed. A

variety of working uids have been proposed; the two most common absor bent refrigerant pairs are LiBr

water and water ammonia. A key gure to describe the performance of a thermally driven chiller is the

thermal Coefcient of Performance (COP), dened as the produced cold per unit of driving heat.

Single-effect absorption systems are limited in COP to about 0.7 for LiBr water and to 0.6 for ammonia

water, and hence require a rather large solar collector area to supply the heat needed for their operation.

This collector area can be reduced by employing systems with improved COP, which may be achieved

using a higher temperature heat source. I n this case, the absorption systems must be congur ed in stages.

The principle is to utilize the heat rejected from the condenser to power additional desorbers, thereby

approximately doubling or tripling the amount of refrigerant extracted out of solution with no need for

additional solar heat. These systems need, however, high temperature collectors, such as evacuated tube or

concentrating collectors. The higher cost of the cooling machine and the solar collector should hence be

considered, Most solar-powered absorption cooling projects to-date have utilized single-effect systems,

with low-temperature solar collectors. Developments in gas- red absorption systems in recent years, mainly

in the USA and Japan, for LiBr water chillers, have made available in the market double-effect systems

with COP in the range 1.0 1.2. Triple-effect systems are still under development but close to the market,

with COP of about 1.7. These systems may be adapted to and employed in a solar-powered installation with

high temperature solar collectors. Fig. 2 compares the performance of several multi-effect chillers, showing

the COP as a function of the solar heat supply temperature for typical single-, double-and triple-effect

chillers with the same component size and under the same operating conditions. The corresponding Carnot

performance curve is also shown for comparison. The single-effect system gives best results in the

temperature range 80 1001C; for a higher supply temperature, it is worth switching to a double effect

system, up to about 1601C, and then to a triple-effect. Absorption chillers are available from various

manufacturers, in large capacities up to several thousands kilowatts.

However, in the range of small capacities (of 100 kW) only very few systems are available in the market.

Adsorption chillers working with solid sorption materials are also available. The main difference compared


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to the absorption systems is that two or more absorbers are necessary in order to provide continuous

operation. Adsorption systems allow for somewhat lower driving temperatures but have a somewhat lower

COP compared to absorption systems under the same conditions. Silica gel adsorption machines with

cooling capacities of about 75 kW to several hundreds kilowatt are produced in Japan. Small adsorption

machines are not commercially available yet, but are expected to enter the market in the near future. The

simplicity of the process, the wide range of heating temperatures and other advantages.

Noiseless operation could lead to a large number of small solar assisted air conditioning applications.

Further research and development work on small-size adsorption machines is necessary in order to reduce

their volume and increase the power density.

Open-cycle systems

Desiccant systems are essentially open sorption cycles, utilizing water as the refrigerant in direct contact

with air. The desiccant (sorbent) can be either solid or liquid and is used to facilitate the exchange of sensible

and latent heat of the conditioned air stream. The term open is used to indicate that the refrigerant is

discarded from the system after providing the cooling effect and new refrigerant is supplied in its place in

an open-ended loop. In this type of systems the process air is treated in a dehumidier and goes through

several additional stages before being supplied to the conditioned space. The sorbent is regenerated with

ambient or exhaust air heated to the required temperature by the solar heat source. Most desiccant systems

presently on the market use a solid sorption material such as silica gel. Since the solid desiccant cannot be

circulated by pumping, these systems usually employ a rotary bed carrying the sorbent material, referred to

as a desi ccant wheel, to allow continuous operation. Systems employing liquid sorption materials are less

widespread but also available on the market. They have several advantages such as the ability to contain,

pump an d lter the desiccant, co ol during absorption and heat during desorption, the possibility of energy

storage by means of concentrated hygroscopic solutions, as well as bacteriostatic qualities.

Overview of the SACE project

The SACE (Solar Air Conditioning in Europe) project was aimed to assess the state-ofthe-art and to provide

a clear picture of the potential, the future needs and the overall perspectives of this technology. The main

objectives of the project were: (1) To conduct a horizontal study on the state-of-the-art of environmentallyfriendly technologies for air conditioning of buildings in Europe with an emphasis on cooling and

dehumidication (summer air conditioning) and low temperature heat-driven technologies; (2) To assess

the potential of these technologies for using solar heat as the driving mechanism; (3) To achieve a broad

overview about the state-of-the-art of solar assisted air conditioning in Europe; (4) To identify the strong

and weak points of the reviewed technologies in relation to their energy performance, environmental impact


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and nancial viability; (5) To identify future needs and necessary actions in order to better exploit the

potential of the identied technologies and to contribute to the advancement of promising technologies, that

will accelerate their introduction into the market.

In order to assess existing installations and research on components for solar assisted cooling systems, the

CORDIS database of the European Commission was screened for EC funded projects; projects from the

IEA Solar Heating and Cooling Program were also included in the survey. More detailed data on solar

cooling applications were also collected by the SACE partners on national level, in the participating

countries.

The above search has revealed many research and development projects on new components and systems,

as well as demonstrations of solar-assisted air conditioning, carried out in Europe under both national and

European programs. Several innovative concepts and component developments have evolved. A

standardized methodology was hence devised under the SACE project and used to collect and assess thedata from the various projects, in order to provide a comparative description and evaluation of technical

developments at component and system level, and to assess the performance of demonstration projects.

Using these data along with a method prepared for preliminary economic investigation, a techno-economic

study was performed for different heat-driven technologies (absorption, desiccant, adsorption, jet cycles)

combined with different types of solar thermal collectors, for different loads and climatic conditions.

Malaysia is located in Southeast Asia. Climate in Malaysia is categorized as equatorial

which is being hot and humid throughout the year. The average rainfall is 250 centimeters a year

and the average temperature is 27 C. The climates of the Peninsula and the East differ, as the

climate on the peninsula is directly affected by wind from the mainland, as opposed to the more

maritime weather of the East. Malaysia is exposed to the El Nio effect, which reduces rainfall in

the dry season.

Malaysia faces two monsoon winds seasons, the Southwest Monsoon from late May to

September, and the Northeast Monsoon from November to March. The Northeast Monsoon brings

in more rainfall compared to the Southwest Monsoon, originating in China and the north Pacific.

The southwest monsoon originates from the deserts of Australia. March and October form

transitions between the two monsoons.

Local climates are affected by the presence of mountain ranges throughout Malaysia, and

climate can be divided into that of the highlands, the lowlands, and coastal regions. The coasts

have a sunny climate, with temperatures ranging between 23 C (73.4 F) and 32 C (89.6 F), and


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rainfall ranging from 10 centimeters (4 in) to 30 centimeters (12 in) a month. The lowlands have

a similar temperature, but follow a more distinctive rainfall pattern and show very high humidity

levels. The highlands are cooler and wetter, and display a greater temperature variation. A large

amount of cloud cover is present over the highlands, which have humidity levels that do not fall

below 75%.

4.0 Potential to society, economic, geographic conditions, and consideration for successful

commercial implementation in Malaysia.

Being a maritime country close to the equator, Malaysia naturally has abundant sunshine

and thus solar radiation. However, it is extremely rare to have a full day with completely clear sky

even in periods of severe drought. The cloud cover cuts off a substantial amount of sunshine and

thus solar radiation. On the average, Malaysia receives about 6 hours of sunshine per day. There

are, however, seasonal and spatial variations in the amount of sunshine received. Alor Setar and

Kota Bharu receive about 7 hours per day of sunshine while Kuching receives only 5 hours on the

average. On the extreme, Kuching receives only an average of 3.7 hours per day in the month of

January. On the other end of the scale, Alor Setar receives a maximum of 8.7 hours per day on the

average in the same month.

Solar radiation is closely related to the sunshine duration. Its seasonal and spatial variations

are thus very much the same as in the case of sunshine.

The climate of Malaysia was thoroughly studied as it will be the most important factor in

the implementation of the solar air- conditioning systems in Malaysia. Based on the study of

Malaysian climate there is approximately of 11hours of sunlight but receives peak sunshine

about only 6hours. Following is the solar radiation map of peninsular and also Borneo Malaysia.

The figure shows the solar fallout in Malaysia.


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Energy has become a fundamental part of people's daily lives as well as being vital to the

social and economic progress of every country. In worldwide, energy in term of electricity, such

as electricity and heat generated from solar, wind, ocean, hydropower, biomass, geothermal

resources, bio fuels and hydrogen derived from renewable resources is a necessity in our daily life

as it provides power for lighting, electrical appliances, space conditioning, and water heating.

Particularly in Malaysia, the residential energy use accounts for more than 14,365 GWh or 19%

of total electricity consumed in Peninsular Malaysia in year 2006. Malaysia is one of the country


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that are still use fossil fuels as main source of energy today but also aware of the consequences of

relying on this energy source for our natural environment. The climate of Malaysia is tropical and

humid. So , its suitable to use safer alte rnative energy sources such as solar, wind, water and so

on. Since there is more concern on energy conservation and environmental protection, the global

priority has been increasingly addressed on the solar energy. Solar energy as a clean energy source

and safer alternative renewable energy is abundant in Malaysia. The weather condition in Malaysia

is very suitable for solar implementation. This is because the weather condition is almost

predictable and the availability of sunlight for more than 10 h daily. As it is possible to have about

6 h of directs sunlight with irradiation of between 800 W/m2 and 1000W/m2, it is already very

good to consider for the usage of solar energy. This country experiences relatively uniform

temperature throughout the year, with the mean temperature in the lowlands ranging between 26

C and 28C.

Solar energy innovations are likely to concern public and business policy makers in the

decade ahead as the common problem what the world is facing nowadays is the energy problem.

Sooner or later, the focus of concern is moving from the general to the specific, from the macro to

the microenvironment, from the national level to the regional and state levels. Therefore,

particularly in Malaysia, this is alarming that everyone needs to create awareness about solar

energy as the government is also planning to do a lot of awareness regarding the renewable energy

for the regard of benefits for people, for instance, in the l0th Malaysia Plan (2011-2015) it has alsoset a target of 5.5% renewable energy in the country's energy mix.

In term of creating public awareness on benefits of solar energy use and the environmental

effects, nowadays it can be seen that green campaign is one of the hot topics among the Malaysians.

There are many organizations organizing green campaign such as Environmental Protection

Society Malaysia (EPSM), Malaysia Environment NGOs (MENGO) and Treat Every

Environment Special Sdn. Bhd. (TRESS). As an example of the benefits of solar energy

technology instalment, price of solar energy, which is the most concern factors on this regard, is

still on the outer edge of affordability and vary depending upon the amount of energy needed and

the size of the panels required for instance, solar energy systems cost between RM 10,400 (2,400)

and RM21,500 (5,000) installed for domestic hot water. Furthermore, DIY hot water heating kits

are available which cost about RM6,500 (1,500) to compare with photo voltaic systems which


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are more expensive costing from RM21,500 (5,000) to around RM40,000 (9,000) installed. In

term of solar energy production and consumption status in Malaysia, it can be seen that solar power

in Malaysia or also known as photovoltaic (PV) system is estimated to be four times the world

fossil fuel resources. For instance, the 5-year Malaysian Building Integrated Photovoltaic

Technology Application Project (MBIPV), jointly funded by the Government of Malaysia, the

Global Environment Facility (GEF) and the private sector, has been launched in 2005 where the

project has several demonstrations of PV projects in various sectors including residential houses

and commercial building.

Daily electricity use was surveyed in Malaysia Social viability of solar energy use can be

counted in form of daily electricity use in Malaysia as the household electricity consumption is

very much dependent on the family size, living habits, age and number of electrical appliances andusage time. According to the study, the average electricity consumption can be seen into three

different categories of household; the low cost house with average spending of approximately

RM65 per month, medium cost house spending about RM110 per month and for bungalow

spending up to RM350 per month. The cost of energy used by various appliances in Malaysia is

shown in Figure below.


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Furthermore, it also can be seen that water heating is the second largest cost day after air

conditioning according to Table 3 indicating the survey data for the average monthly electricity

consumption and water usage for a typical household in Kuala Lumpur where the usage of water

heater is 14% of total energy consumption per month in a typical urban house.

According to the above-mentioned surveyed data, it can be seen clearly that consumption

of energy, particularly electricity, is relatively high with the time line of the season. In other words,

it is showing that use of solar energy technology is better to increase along with creating more

awareness of the long term sustainable benefits of this technology to the society and environmentas well as by emphasizing more on incentives of new business entry for this particular energy

sector.

It is evident to say that solar energy systems can be considered either as the power supply

or applied directly to a process. Furthermore, large scale solar thermal systems with large collector

fields are economically viable due to the usage of stationary collectors as solar PV systems are

reliable substitutes to be considered as an innovative power source in building, processes industries

and water desalination systems. Besides that, the economic outlook for these systems is more

viable when the system is operating in remote regions where there is no access to a public grid. In

addition, other technical and economic variables such as wear and tear, initial and running costs,

economic incentives, PV module diminishing price rate and oil price raises should not be

neglected. In term of world solar energy use, the various existing solar technologies can be seen


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in order to enhance the understanding of each technology and its associated challenges; the price

for installation. Moreover, these outlooks provide a suitable basis to recognize advantages and

drawbacks in its current usage of energy and further implementation in Malaysia on this regard

specifically with the availability of the resources for the full scale development as there is a great

potential for Malaysia to move from fossil based generation towards the renewable energy.

Therefore, implementation solar air-conditioning in Malaysia is possible but will require more

time and not be possible in the next coming year (5-10 years) due to the cost of the collector panels,

installation and maintenance of is still beyond reach of most average income Malaysian which

make up 60-75% of Malaysia population. Furthermore, for many families that reside in

condominiums and flats, solar energy may not be reachable for them as their location may not

permit the installation of the solar equipments and the roof space of c ondominiums may not

accommodate the total solar needs of all the residents in a particular complex. As a conclusion,solar implementation for the current economic and social awareness requires more development

and requires more time.


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http://www.sciencedirect.com/science/article/pii/S0038092X11003227#b0035http://www.sciencedirect.com/science/article/pii/S0038092X11003227#b0035http://www.sciencedirect.com/science/article/pii/S0038092X11003227#b0035

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Solar Air Conditioning Research Paper (Final)

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