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ISSN: 2348-20 79     Volume-5 Issue-2 
International Journal of Intellectual Advancements 
and Research in Engineering Computations 
 
Fabrication of Desiccant Assisted Cooling system 
1 2 2 2 2
K. Ganesan , M. Hariharan , R.Dinesh kumar , V. Tony , S.S. Dhamotharan , 
1 2
Associate Professor,  UG Students 
Department of Mechanical Engineering, Nandha Engineering College, Erode-52, 
Tamil Nadu, India. 
1 2
[email protected], [email protected] 
 
Abstract - Solid desiccant cooling (SDC) system is an loads. So desiccants are used to improve the indoor 
alternative air conditioning system. Desiccant plays a quality of all types of buildings efficiently controlling 
vital role in overall performance of the whole system humidity in large quantities fresh, ventilation air. 
particularly in dehumidification and regeneration  
capacity. By this review we recapitulate that novel solid 
In this method, a desiccant with great 
desiccant materials like zeolites, silica can be adopted in 
attraction to moisture removes wetness from air via 
the SDC system. In order to resolve environmental and 
sorption process.  
economic issues with the present space cooling system, 
This releases heat and increases air 
the implementation of the SDC system will be the better 
answer to the problem. The Aim of the proposed system temperature. The Fusion of heat exchange with 
is to develop drying technology reduce the moisture surrounding air and evaporative or conventional 
content in air provider cooling in space and produce a cooling coils then cools and dries air. Humid loads, 
good quality cold air. Zeolites are used as moisture temperature are very effectively met by separating this 
adsorbents. When this system is build up we can achieve way. This desiccant with hygroscopic material 
EEE i.e. Environmental friendly, good Energy efficiency property is dried out to complete cycle using thermal 
low power consumption and more Economic cooling energy supplier waste heat. Commercial available 
system. This system is used for industrial prevention desiccants include silica gel, zeolite, activated 
fungus control and reduces many health affects like alumina, titanium silicate, and lithium chloride. 
asthma.  
  
Index words - Solid desiccant cooling, Desiccant 
material, dehumidification and regeneration, comfort air 
conditioning. 
I. INTRODUCTION 
      In present, Swift growth of society and 
environment brings greatest pressure on globe. World  
faces more serious environmental problems such as Fig. 1 Desiccant air flow process chart 
global warming and haze that is smoke, dust, liquid  
moisture droplets. Study on any field must think about 
seriously on less contamination of environment by 
harmful substances. Researches on air conditioning 
are no exception. Till now, commonly adopted 
refrigeration air conditioning technology is vapor 
compression which consumes lots of electricity and 
releases green house gases. Desiccant assisted 
refrigeration air conditioning system will be the 
promising desirable alternate to commercial vapor 
compression refrigeration air conditioning system 
.When fresh outdoor air enters into building it comes 
with high humid load comparative to building internal 
 
latent load. Conventional vapor compression cooling Fig. 2 Air flow process direction 
system is not suited to efficiently treat large humid 
 
 
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The eminent benefit of this system is being 
environmental friendly saving energy and controlling 
humidity temperature separately. SDC subjects to less 
corrosion   it reduces total residential electricity by 
25% or more in humid regions. Providing dry, clean 
and more comfortable indoor environment with low 
electricity bill. 
 
II. LITERATURE SURVEY Fig. 3 Desiccant Wheel is Equally Divided for 
Adsorption and Desorption 
[1] X. Zheng et al made a study and concluded that 
solid desiccant cooling which can be driven by low 
grade heat is considered as promising method for 
assuring clean and economic air conditioning.  
 
[2] Hazeeb Halid et al, conducted an experimental 
analysis of solid desiccant wheel dehumidifier and 
stated that regeneration temperature increases more 
moisture is removed from the process air due to 
enhanced heating of desiccant wheel surface.  
Fig. 4 Psychometric changes occurring in the 
 
desiccant wheel 
[3] A.Z. Zainal et al, have found that desiccant 
 
dehumidifier has the ability to reduce humidity within 
a period of time. 
IV. DESICCANT MATERIAL 
 
[4] M.A.Mandegari et al, have carried out many There are several commercially available 
experiments using both liquid and solid desiccants in desiccants. The most commonly applied in desiccant 
air conditioning systems concluded that the solid wheels are silica gel and lithium chlorides. Activated 
desiccants show considerable promise producing a carbon, activated alumina, molecular sieves, activated 
higher degree of the humidification than the liquid clay and calcium chlorides are also used. The material 
desiccants. The electrical energy requirement can be used in this wheel is a Zeolite which has one of the 
very low comparing with conventional cooling hygroscopic characters. Zeolites are synthetic 
systems. The origin of thermal energy can be distinct desiccants derived from sodium or calcium crystalline 
(i.e., solar, waste heat, natural gas). and can be manufactured with specific pore sizes so as 
 to allow 
[5] Kodama A et al showed that the dehumidifier is for the adsorption of a particular molecule 
the prime component of a desiccant cooling system characteristic. For instance, decreasing the Si/Al ratio 
and the cooling COP (coefficient of performance) is in alumino silicate zeolites results in a structure with 
significantly improved by enhancing the performance increased hydrophilic characteristics. They have a 
of this component. good adsorption capacity over low levels of air 
relative humidity. When compared to silica gel, it 
III. DESICCANT WHEEL exhibits half of average capacity per unit weight, 
although it also exhibits an adsorption capacity less 
Desiccant wheel is an air to air heat and mass 
sensible to increased temperatures. It is an efficient 
exchanger, with a relatively low rotation speed. Wheel 
desiccant, allowing for the humidity to be lowered 
has a frame with film of desiccant material layered on 
beyond detectable levels. Moreover, it can be shaped 
the same. The channels in the frame come in various 
to 3 Å, providing a selective sorption of 2.8 Å water 
shapes such as sinusoidal, honeycomb, triangular etc. 
molecules, mitigating indirect contamination. 
The frame Wheel is axially crossed by two main 
streams. The porous desiccant medium of the matrix is 
V. DEHUMIDIFICATION 
cylindrically operated for adsorption and desorption. 
In process part of the wheel, dehumidification of air Air dehumidification can be achieved by two 
takes place, and in the reactivation part of the wheel methods: (1) Cooling the air below its dew point and 
humidification of the air takes place. The rotation of removing moisture by condensation   
the wheel causes periodic reactivation of the (2) Absorption by a desiccant material. 
adsorption part.                                                                                  D   e  h  u  m   i d  ification is the process of removing 
 water vapor from moist air. Here, absorption method 
is used due to the easiness created by the solid 
desiccants. In absorption method of dehumidification, 
 
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desiccant particle (zeolite) absorbs the water vapor in  
air. The solid desiccant particle is a compact packed Fig. 6 Fabricated Desiccant Wheel 
arrangement, where cold and moist air enters which  
interacts with the desiccant and loses the moisture to  Zeolites are solid desiccant and that can carry 
the desiccant. As the desiccant absorbs water. To water in crystalline structure. Zeolites have a very 
maintain the dehumidifying capacity of the system, high capacity of absorbing moisture more strongly 
the absorbed water must be removed from the than the silica or clay. Zeolites are most economic 
desiccant. This is achieved by regenerating the desiccants because of its high adsorption capacity at 
desiccant particle where the water vapor in the lower relative humidity. It has hygroscopic property 
desiccant is evaporated. The wheel is then rotated so that water is absorbed or deabsorbed by the micro 
that the desiccant portion that has picked up moisture capillary until vapor pressure equilibrium is achieved 
is exposed to hot reactivation air and its moisture with relative humidity of surrounding air. Channel 
removed. Another desirable situation is when the cost size of zeolite is 2.5 to 4.3 angstroms in dia. The 
of dehumidification with a desiccant is lower than the rotational speed of the rotary desiccant dehumidifier is 
cost of dehumidification with a refrigeration system. inversely proportional to sorption time. When the 
The figure-8 shows the concept of dehumidification. desiccant wheel rotates must faster than the optimum 
speed, the adsorption and regeneration process will 
VI. EXPERIMENTAL SETUP too small which results in poor performance. From the 
An experimental set up is established as previous study the optimum rotational speed of 
shown in figure. The experimental set up consists of desiccant wheel is calculated around 25-30 rph. In our 
main components like desiccant wheel, compressor, project for obtaining this rph a small DC motor of 12v 
condenser, evaporator, blower, insulation air duct. is used and a pulley of dia 3cm is connected to shaft of 
The operation of system includes 2 modes one is the motor. The desiccant wheel is of 30cm dia and by 
operating in dehumidification process and second is using belt drive to drive wheel thereby obtaining 
regeneration process. A desiccant wheel of 300 mm necessary speed reduction. Calculation of RPM of 
dia has been constructed using 100 mm width and desiccant wheel is 5RPM.Thermocouples and subzero 
2.5 mm thickness. The desiccant wheel has four is used for measuring the hot and cold temperatures. 
major parts outer layer, separation part, sheet metal  
with fine holes and rod. It is circular plate with 
honey comb structure the zeolites and carbon are 
stuffed in place between the spokes in wheel. The 
frame has made for 3feet in mild steel width of 
frame is 400mm and its height is 750 mm. 
Desiccant wheel is placed in middle of the frame 
where 12V D.C motor is used to rotate the wheel. 
The wheel and its supporting structures are welded. 
 
 
Fig. 7 Overall Setup 
 
 VII. WORKING PRINCIPLE 
 
Fig. 5 Inner partition of Desiccant wheel   The rotor is made up of corrugated sheets, 
 which are filled with desiccant. It is divided into two 
 sectors which are separated with the help of seals, the 
dehumidifier or process zone (approx. 75%) and the 
reactivation or regeneration zone ( approx. 25%) as 
shown in fig. Air passes through the rotating desiccant 
wheel (approx.0.5-1rpm), its moisture is transferred to 
the desiccant wheel then warm & dry air is passed to 
the part2 (conditioned air).  In desiccant wheel the hot 
and humid air is passed where the desiccants will 
 remove the moisture present in it now the temperature 
 
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increases. The process air temperature is now hotter REFERENCES 
and drier this is reduced to the comfort condition by [1].  M.A. Mandegari, H. Pahlavanzadeh, Introduction 
means of sensible coolers (E.g.  Cooling coils, heat of a New Definition Effectiveness of Desiccant 
exchangers). The warm and humid return air from Wheels, Energy 34 (2009) 797e803 
conditioned space is further heated up of the required  
regeneration temperature of desiccant and this [2]. Kodama A, Goto M, Hirose T, Kuma T., 
regeneration steam of air is passed through desiccant Experimental Study of Optimal Operation for a 
to remove the moisture from desiccant. Honeycomb Absorber Operated with Thermal 
Swing. J Chem Eng Jpn 1993; 26:530e5.  
VIII. RESULTS AND DISCUSSIONS [3].  Hazeeb Halid., Experimental Analysis of solid 
As the moisture being removed in desiccant, desiccant wheel dehumidifier Volume 4, Issue 3, 
the process air outlet temperature is more compared to May- June, 2016, pp.104-109 6, DOA: 27052016 
the inlet air temperature. Experimental values of the  
inlet air and outlet process air temperature is measured 
using the thermocouple and tabulation is made. The 
final cooling temperature is measured with the help of 
the sub zero measuring equipment. As the moisture is 
removed in air the cooling takes place rapidly and the 
efficiency of the system is more and low power 
consumption. 
 
TABLE I. Experimental Values of Outlet and Inlet 
Temperature 
  
Inlet Temperature(°C) Outlet temperature(°C)  
  
30.4 40.6 
31.7 43.9 
 
TABLE II. Experimental Values of inlet temperature & 
final cooling temperature 
  
Inlet Temperature(°C) Cooling 
 
temperature(°C)  
 
30.4 10 
31.7 11.5 
IX. CONCLUSIONS 
 Rotary desiccant cooling system is typically a 
thermal activated method mainly consumes low grade 
heat sources. There by alleviating the peak electrical 
demand caused by the traditional cooling systems. 
Due to moisture removal the corrosion problem in 
equipments may be reduced. We achieved improved 
indoor quality by implementing this system. It has 
huge application in food processing industry, Dairy, 
schools, and Meteorological laboratories and in many 
other domestic applications. In conclusion, further 
improvement in energy utilization rate, reduction in 
cost and size, standardization in design and production 
are the key issues faced by the rotary desiccant air 
conditioning technology for achieving more extensive 
application.