FIELD OF INVENTION
The invention is related to the cooling, using evaporative/desert coolers in arid/dry regions. More specifically the invention is related to the cooling pads used in desert coolers. Pads are made out of mitti/clay which can be locally available, sustainable, biodegradable, easy to manufacture and cost effective. These pads increase the humidifying efficiency and in turn have an increased cooling effect of the desert cooler.
BACKGROUND OF THE INVENTION
In arid and semi-arid climates/regions, mostly evaporative air coolers are popular among middle and lower-income group people as it provides cost-effective respite from the harsh dry summer of these regions/climates. As evaporative cooling is effective in arid summer and is available at a low cost. Evaporative cooling has many environmental benefits as compared to the conventional VCR (Vapour Compression Refrigeration) system like- it is free from chlorofluprocarbon (CFC), Hydrochlorofluorocarbon (HCFC); reduction of power consumption so does the reduction of emission of carbon dioxide (CO2).
In coolers, many types of cooling pad materials are used for evaporative cooling like honeycomb made up of cellulose, wood wool, khus fibres, coconut fibres, jute fibres etc. Cooling pads other than the honeycomb, have humidifying efficiency ranges from 60 to70% [1,2,3] whereas honeycomb has up to 85% humidifying efficiency [1]. These existing pads are biodegradable as they are made up of cellulose material, wood wool, khus, coconut and jute

fibres but with disposal issues. After use, the user throws them and people do not wait for their natural disposal because natural disposal takes time, and these are normally, burnt. On burning they create pollution.
Most of the reputed desert cooler manufacturers are. using honeycomb and wood wool cooling pads. In coolers, the cooling pad is the most important part. It is always desirable to have higher humidifying efficiency to get better comfortable conditions in the room in dry summer. Different types of cooling pad materials have humidifying efficiencies such as honeycomb has 57-85% [1], wood wool 60-71%, khus 55-64% and coconut pad 50-69% [2] and jute fibres 52-62% [3].
If this humidifying efficiency of cooling pads increased, and same time less costly and disposal also environment friendly; these characteristics increased the desert cooler market. Clay/mitti ball based cooling pad is one such cooling pad which is. of low cast and better humidifying efficiency and no disposal issues.
Most of the earlier studies involving earth are devoted for preserving and storage of food products, vegetables etc for example Jong [4], a Chinese inventor, developed a Jar fi-idge made up of fired clay. Jar fridge/refrigerator having a new structure that can store food for a long time is suitable for storing fermented foods. Taking earth/mitti/clay as media Mansukhbhai Raghavjibhai Prajapati, a traditional clay craftsman from Gujarat, has developed a Mitticool fridge [5], it is a small refrigerator made of clay again mainly for storing vegetables, fruits, milk and water.
Another clay based cooling application, shown by Najwa H. Samrgandi [6], which developed a high production of Hydrogen (HHO) system in this clay based Zeer pot is configured to reduce, the temperature inside the HHO generator by evaporation of water on the surface of the Zeer pot; this is not used for air cooling.

One study, which uses clay for air cooling purposes, done by Delhi architect, Monish Siriparapu, developed Mitti ka Air Conditioning (AC) [7], by using traditional mud technology to build a cooling system. In this mitti based hollow bottles used and water sprayed over them; this is installed it in Deki Electronics Ltd. Noida for maintaining the temperature of Generator. This system is for generator cooling only and has not been used in homes due to its bulkiness.
These systems are only used either for preserving food and vegetables and not used for air cooling, other being bulky not suitable for homes cooling for evaporative cooling. Sustainable cooling pads for existing desert coolers giving enhanced cooling for people living in arid/semi arid regions has not been done .

OBJECTIVE OF THE INVENTION
The object of the invention is to provide a mitti/clay balls based cooling pad for evaporative/desert coolers having high humidifying efficiency with ease of manufacturing, cost-effective and biodegradable and environment friendly disposal.
SUMMARY OF THE INVENTION
The object of the invention is to achieve higher humidifying efficiency resulting in an enhanced cooling effect for the coolers used by people living in arid/semiarid regions according to claim 1.
The system consists of mitti/clay balls based cooling pad for evaporative coolers. Evaporative cooling is the most efficient and environment friendly cooling technology which works on the principle that sensible heat is converted into latent heat by water evaporation. This system represents the invention of a mitti/clay ball-based cooling pad. A cooling pad is prepared by mitti/clay (locally available) as a material. Balls can be prepared manually or with machines; mitti balls used as cooling pad in the form of layers of garlands in evaporative/desert coolers. The claimed mitti-ball based cooling pad. provides a greater time of contact for the incoming hot air and has a larger water retention capacity because of an increase in wet area and this increases the humidifying efficiency of evaporative cooling pads made up of clay/mitti balls, going to be used in existing desert coolers. The claimed pad is biodegradable, easily disposable (as used in construction of houses, roads etc), and causes no pollution to its disposal; also has socio-economic aspects.
As per one embodiment, mitti/clay balls are prepared and fixed with each other in the form of garlands by string. There is an arrangement in the balls to let pass the string through them. These garlands are arranged in a layer and layers are.arranged one after other. As per the requirements, pad thickness can be varied by increasing the layers of garlands. Layer made out

of balls netted/shaped in garland can be arranged in a curtain form whether in inline/staggered arrangement.
According to other embodiment of the system, layers of mitti/clay ball based garlands, taking the shape of pad can be hanged and engaged by threads and tightened properly within the existing space for cooling pad in desert coolers. Water using existing pump made to drop over the top of layers of cooling balls and this wetted the balls. In terms of the pad made out of mitti/clay balls lowers the temperature of the air entering into room (by reducing sensible heat into latent and in the process reduce the temperature of conditioned air) and this create enhanced cooling effect.
Another embodiment is helpful in fixing the claimed cooling pad and keeping it wet by a continuous feed of spraying water over it

BRIEF DESCRIPTION OF DRAWINGS
Figure 1 shows the system of cooling pad for enhancing the cooling effect of existing desert coolers.
Table 1 comparative humidifying efficiency and cost of different cooling pads used in evaporative coolers.
The figures depict embodiments of the disclosure for purposes of illustration only. One attuned in the art will readily understand from the following description that alternative embodiments illustrated herein may be employed without departing from the principles of disclosure described herein.

DETAILED DESCRIPTION
For the purpose of promoting an understanding of the principles of the invention, reference will now made to the embodiments illustrated in the figures and specific language will be used to describe them. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as would normally occur to those skilled in the art are to be construed as being within the scope of the present invention.
It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof.
The terms "comprises", or any other variations thereof, are intended to cover a non-exclusive, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such a process or method. Similarly, one or more components, structure preceded by "comprises." does not, without more constraints, preclude the existence of other components, structures, additional components, or additional structures or additional systems. Appearances of the phrase "in an embodiments", "another embodiment", and similar language throughout this specification may, but not necessarily do, all refer to the same embodiment.
Unless otherwise defined, all technical terms and scientific terms used herein have the same meaning as commonly understood by those skilled in. the art to which inventions belongs. The system, methods provided herein are only illustrative and not intended to be limiting.
The technology of the invention is focussed to provide following advantages, such as-
l)Cooling pad system giving higher humidifying efficiency resulting increase in net cooling done by of existing evaporative/desert copier.

2)It can be used in all sizes of desert coolers, having an arrangements for cooling pads
3) It is biodegradable and disposal (as it is reused as a raw material for construction of houses, roads etc) purposes is non-polluting and very easy.
Embodiments of the present invention will be described below in detail with reference to accompanying figures.
Invention is envisaged in a setup where people belongs to middle class/lower income group residing in the arid and semiarid cli mat e//reg ions uses evaporative /desert cooler to beat the extreme heat in the months dry seasons of summer with dry and hot conditions. In furtherance, people which are environmental and energy conscious also uses this type of evaporative cooling technology offered by desert cooler pad system with increased humidifying efficiency and capable of giving better cooling effect,
Figure 1 illustrates system for the desert cooler used in dry summer of arid/semiarid regions. This cooling pads system consists of locally available sand used to prepare earthen pot or clay balls 1 of 15 to 20 mm diameter. Getting the useful sand/ clay to make these balls is same as •potter do to get earth/sand/clay for manufacturing earthen pots.
These clay balls are garlanded 2 using string/thread. These garlands 3 are arranged in layers either inline or staggered way 4 to form the curtain. These garlands of clay/mitti balls are fixed / connected / attached to the existing slots for the cooling pads of desert coolers. This, curtain or layers of cooling pads are hanged from the plate 5 via strings to hole 8 made on plate 5. Water from the tank 10 of cooler poured over, plate 5 via passing through pipe 6 spread over 5 and through 7 i.e., holes, water drips over the mitti balls based cooling pads 1,2,9 uniformly over the curtain of clay balls based cooling pads.
Water, which dripped through 8 over the cooling pad 9. Clay/mitti balls 1 soaks the water, and the incoming hot dry air when, comes in contact with it, encounters large wetted surface area

of clay/mitti based balls; this is the reason for being increased residual time. This increases the humidifying efficiency of the system of cooling pad as shown in one of the embodiments.
Since, new cooling pad is made out of clay so, it is noted that their disposal is very easy, non-polluting as compared to other contemporaries cooling pads like honeycomb, wood wool, khus fibres, coconut fibres, jute fibres etc .
If clay balls based cooling pads rendered unusable then thay can be reused as a raw material for the constructional material for houses, roads etc. No burning, so, no pollution as with the case Of other existing cooling pads.
There are available solutions like honey comb pads made of cellulose material have better humidifying efficiency. Humidifying efficiency is the measure of how much pad can add moisture in incoming dry hot air. Humidifying- efficiency is also known as "Saturation Efficiency" because it refers to the amount of moisture that the media can evaporate into the air. The evaporative cooling efficiency or humidifying efficiency can be calculated [I2]by equation 1.

77 =

T -T
'id 'ad
T -T
JJ ■"" (])

where
7 ld = inlet dry bulb temperature of incoming hot dry air
T od = outlet dry bulb temperature of outgoing air
T •"" =Saturation temperature

Table 1 presented the comparison of humidifying efficiencies and relative cost of various cooling pads available in market with clay/mitti balls 1,2 based cooling pads shown in figure 1. Both factors i.e. humidifying efficiencies and.relative cost governs the acceptability of the product among end users. The normal cost for making a mitti/clay ball based cooling pad for a single unit of desert cooler roughly comes to about 50 rupees. It is evident honeycomb has higher humidifying efficiency from mitt/clay balls based cooling pads; humidifying efficiency of new clay balls based cooling pad (83%) is very closely behind the honey comb (85%) and cost is very low as compared to honeycomb cooling pads. Cooling pad described and presented is biodegradable and being made up of mitti as its disposal is pollution free.
This is the solution for tackling the dry summers wherever desert coolers are very effective and by using the mitti/clay balls based cooling pad's increases the humidifying efficiency and thus net cooling effect offered by desert cooler employing this new pad system.

LIST OF REFERENCE SIGNS
1. Mitti Balls (10-15mm diameter)
2. Balls garlanded using string
3. Garlands of mitti/clay balls arranged, as curtain
4. Cooling pads arrangements inline/staggered
5. Plate having holes for hanging mitti/clay balls based garlands and holes for dripping water.
6. Water carrying pipe
7. Holes for water spreading arrangement
8. Holes for hanging mitti/clay balls based garlands cooling pad arrangement
9. Cooling pad and cooling pad guide sheet
10. Water tank

Cooling pads Honeycomb pad Wood wool pad Khus pad Coconut pad Jute pad Mitti-Ball Pad
Humidifying efficiency (%) 85 71 64 69 62 83
Cost($/m2.) 4.40 [8] 2.64[9] 1.98[10] 1.32[U] 1.35 0.63
Table 1: Comparison of humidifying efficiency and cost of different cooling pad materials

References
[1] Malli Abdollah, Reza Seyf Hamid, Layeghi Mohammad, Sharifian Seyedmehdi, Hamid Behravesh. Investigating the performance of celliilosic evaporative cooling pads. Energy ConversManag 2011; 52:2598-603.
[2] J.K. Jain, D.A. Hindoliya, Experimental performance of new evaporative cooling pad materials, Sust. Cities Soc. 1 (2011) 252-256.
[3]F.AL-Sulaiman; Evaluation of the performance of local fibres in evaporative cooling. Energy Convers. Manage 43(2002)2267-2273.
[4] https://patents.google.com/patent/KRl9990014620A/en?oq=KRl 9990014620A
[5] https://mitticool.com/product/mitticool-clay-refrigerator50-liter/ [6] https://patents.google.com/patent/US9410254B2/en?oq=US9410254 [7] https://www.youtube.com/watch?v=nt2oyaP2m6Q
[8]https://vvvvw.dpengineers.co.in/honeycomb-cooling-pads-4460088.html Accessed 23.12.2021.
■ ?'.
[9] http://www.akgpackers.com/Wood_vvool.html [Accessed 28. 12. 2021]
[10]https://khusplaza.com/collect ions/vet iver-ciirtains-and-coolers/prodiicts/khus-cooler-pads[Accessed 25.12. 2021]..
[1 l]https://www.indiamart.com/proddetail/air-cooler-pad-23032599612.html[Accessed 20.12.2021]
[12] ASHRAE standard ANSI/ASHRAE 133-2001 (2001). Method of testing direct evaporative air coolers, p. 24.

PATENT CLAIMS

We claim:

1. A system shown in fig 1 is clay balls 1 based on evaporative cooling pads used for desert coolers applicable in dry summers of arid and semi-arid regions or any other climate where evaporative coolers with cooling pads are in practice. This pad comprises of clay/mitt based balls of diameter (10-15mm) are garlanded 2 with string. These garlands are arranged in the form of layers 3, taking the shape of curtain to let dry hot ambient air to pass through them. Layers of mitti/clay balls based garland can be inline or staggered arrangement 4
2. System in fig 1 as claimed in claim 1, the clay/mitti balls based cooling pads adopted as per size /space of the slot/space for the cooling pads in the existing desert cooler. The clay/mitti ball based garlands 3 can be hanged easily with slight alterations 5,8 in the existing desert cooler's slots for cooJing pads.
3. Cooling pads claimed in 1, increases the humidifying efficiency of the clay/mitti based cooling pads 2 by enhancing the time of contact of the dry outside/ambient air being sucked into the cooler through water laden mitti ball's garlands.
4. System as in figl, claimed in claimlto 3can be used in hybrid form. Means, cooling pad can also be hybrid form i.e., cooling pads made up of say wood wool, khus fibres etc. the clay/mitti balls suitably embedded or arranged in the existing cooling pads of say wood wool, khus fibres, that improves the humidifying efficiency of existing pads.
5. System in fig 1, as claimed in lto 3 can act as a blinds in windows of houses with arrangement of water circulation similar to 5,6,7 8,9 and 10. Water dripping over these blinds made up of mitti/clay balls and collected and re circulated again using pipe with arrangement for make up water.

6. Cooling pad system claimed in claim 1 is biodegradable and can be self disposed on
throwing it after crushing these clay based balls; easily mixed with soil of garden etc,
pollution free disposal.
7. System claimed in claim 1,3 can be extended for cooling building complexes and
eventually help in reducing building air conditioning load. This is by putting mitti
based balls in the form of mega scale curtains and letting the air pass through them . It
also does not spoil the aesthetics of landscape surrounded the building.
8. This system can be used in water purifiers by using a multi-layer pattern of balls.- When
water fall on the uppermost layer initially and gradually go to downwards, till reaches
the end stage, one can get purified water.-