The experiment was devised as a prototype of the downdraught evaporative cooling system for the nottingham university entry to the 2010 solar decathlon europe competition. Analysis of the system response of a spray passive. Passive downdraught evaporative cooling applied to an. Csiro has invented a new three in one solar air conditioning system that provides hot water, cooling and heating. The pdec system consists of modified wind towers 10 which guide outside breezes over a. A spray passive downdraft evaporative cooling pdec system achieves great savings for space cooling and improves indoor environmental quality by supplying a large amount of fresh outdoor air. A passive downdraft evaporative cooling pdec tower is a component that is designed to capture the wind at the top of a tower and cool the outdoor air using water evaporation. To examine the energy conservation potential of passive. Passive downdraft evaporative cooling pdec evaporative cooling was extensively used in the vernacular architecture of pakistan, iran, turkey and egypt. The water sprayed on the pad gets collected and recirculated by a pump. Iran offers some of the best vernacular examples of passive downdraft towers, some of which used evaporation to supplement the use of thermal mass for cooling as. In the late 1980 s, a number of successful experiments were undertaken which tested the evaporation of water within a downdraught tower, hence the term passive downdraught evaporative cooling pdec. Small droplets of pressurised water can be sprayed into the incoming ambient air at the top of a cooling tower. A novel multistage downdraft evaporative cool tower for space cooling.
While several different types of this particular system exist, pdec tower with spray was studied in. Overview of passive downdraft cooling systems using evaporative cooling the passive downdraft concept comes from vernacular architecture that has been used for thousands of years. Champion cooler down draft evaporative cooler hp 15002200 cfm. Chapter 4 the building architectural design building massing and orientation ther e is a tradeof f between a compact form that minianother energyrelated massing and orientabuilding, the electrical load and cooling load savings mizes conductive heat transfer thr ough the envelope tion consideration is the seasonal wind pattern. Evaporative swamp cooler parts, pads, covers and mastercool pads and pumps. Passive, downdraft, evaporative, cooling, ventilation, europe background passive downdraught evaporative cooling pdec is a technique which may well become a substitute in whole or part for conventional airconditioning. Passive downdraught evaporative cooling pdec is one of the proven alternatives to conventional cooling as its operation requires low amounts of energy with significant reduction in co2 emissions when compared with conventional airconditioners 2. A spray pdec system has been relatively less considered than other passive cooling strategies as one of the viable lowenergy solutions in the cooling of buildings while having a great potential in energy savings. Downdraft evaporative cooling systems can be used for the thermal management of inside spaces in hot dry environments. This is the first of a series of four papers that describe a 3year eufunded research project into the application of passive downdraught evaporative cooling to non domestic buildings. Analysis of a phdc passive and hybrid downdraft cooling.
When evaporative processes are used to cool an element of the building, which then acts as a heat sink, this is known as indirect evaporative cooling. A passive downdraft evaporative cooling pdec tower is a component that is designed to capture the wind at the top of a tower and cool the outdoor air using. Postoccupancy evaluation of passive downdraft evaporative cooling and airconditioned buildings at torrent research centre, ahmedabad, india. Passive evaporative cooling is a cooling method that uses the evaporation of water to cool the air. In this tradition, wind catchers guide outside air over water filled porous pots, inducing evaporation and bringing about a significant drop in temperature before the air enters the interiors. Different types of evaporative devices such as wetted pads and water. Its application is based on the availability of water resources and use of draughts into the building. This can be achieved through use of fountains or more architectural designs such as the evaporative downdraft cooling tower, also called a passive cooling tower. There were 2 types of evaporative cooling, passive downdraft evaporative cooling pdec roof surface evaporative cooling rsec 4. Significance of parameters affecting the performance of a.
An investigation of the scope for improvement of the. Passive downdraught evaporative cooling windtowers cooltowers have received special interests for their energy saving potential. Passive evaporative cooling is one of the most efficient and long recognized ways of inducing thermal comfort in predominantly hot and arid climates. Passive heating and cooling guidelines have changed little in. This paper analyses the integration of a passive downdraught evaporative cooling. Performance control of passive downdraft evaporative. Passive downdraught evaporative cooling pdec origin. Passive downdraught evaporative cooling can also be used in hot dry climates to improve the natural ventilation of buildings by encouraging the convection of air downwards. International conference passive and low energy cooling. Assessment of passive downdraft evaporative cooling. Evaporative cooling has been applied in various forms for several centuries in different parts of the world, particularly in the middle east where various techniques have been employed over time to encourage air.
Passive downdraught evaporative cooling pdec is a traditional means of environmental control that has been used for centuries in parts of the middle east, notably iran and turkey. This paper is focused on the concept and design methodology for a passive downdraft evaporative cool tower application. A spray passive downdraft evaporative cooling system has been regarded as a lowenergy cooling system that leads significant energy savings in the cooling of buildings. The potential application of passive and hybrid downdraught cooling to residential buildings is explored using an experimental facility constructed and tested in seville, spain. One of the most interesting charts is the psychrometric chart with overlays that show the design strategies e. With the aggravating of the global climate warming and energy crisis, using passive cooling technique will be a good solution. Request pdf passive downdraught evaporative cooling. It is designed to capture the wind at the top like a wind tower but provides additional conditioning potential by cooling the outdoor air using water evaporation.
In this paper, the theory of passive downdraught evaporative cooling techniques is analyzed. Passive downdraught evaporative cooling applied to an auditorium. There may be scope for improvement of such systems. Passive evaporative cooling is a very efficient cooling application, but is often offset by fan energy. Passive downdraught evaporative cooling system integration in existing. Pdf this paper analyses the integration of a passive downdraught evaporative cooling. We carry mobile mastercool pads and cooler pumps and can ship anywhere in the continental united states. Passive down draft evaporative cooling is a technique that has been used for many centuries in parts of the middle east, notably iran and turkey. Postoccupancy evaluation of passive downdraft evaporative. When warm, dry unsaturated air is pulled through a watersoaked pad, water is evaporated and is absorbed as water vapor into the air. Pdec is a passive cooling technique which involves spraying of controlled volumes of microscopic water droplets into.
Evaporative cooling differs from typical air conditioning systems, which use vaporcompression or absorption refrigeration cycles. Aug 08, 20 csiro has invented a new three in one solar air conditioning system that provides hot water, cooling and heating. A direct evaporative cooling technique such as the pdecas is a wellknown strategy for reducing the cooling demand in hotdry climates, while indirect evaporative cooling systems or dehumidificationevaporation solar cooling systems 1 can reach good performance results also in midtemperate climatic conditions 2, 3, 4, 5. Estimating the thermal performance of cool towers is given by thompson et al 3. When combined with other passive design techniques, adequate thermal comfort might be achieved without air conditioning.
The system relies on the principle of evaporative cooling. Passive downdraught evaporative cooling system integration. This is the first application of this technique for housing in europe. The work described here is a study aimed at validating the computational fluids dynamics cfd method using experimental data available from a prototype multistage system which existed at bengurion university.
While several different types of this particular system exist, pdec tower with spray was studied in that it is flexible, efficient, and prevalent. Performance control of passive downdraft evaporative cooling. Assessment of passive downdraft evaporative cooling technique for environmental sustainability in buildings ma kamal int. Assessment of passive downdraft evaporative cooling technique for environmental sustainability in buildings mohammad arif kamal intl journal of research in chemical, metallurgical and civil engg. Competence of a spray passive downdraft evaporative cooling. Passive down draft evaporative cooling pdec systems, which have a certain type of evaporative devices such as porous medium and spray, have been developed and integrated with buildings in an attempt to improve the cooling capacity of wind towers. Performance control of passive downdraft evaporative cooling system. Passive downdraught evaporative cooling system integration in.
In indirect evaporative cooling, evaporation occurs inside a heat exchanger and the water content of the cooled air remains unchanged. Competence of a spray passive downdraft evaporative. Integrated dehumidification and downdraft evaporative. An evaporative cooler also swamp cooler, swamp box, desert cooler and wet air cooler is a device that cools air through the evaporation of water. Wind catchers called malqafs captured wind and directed it over porous water pots, thus cooling the air as a result of latent heat of vaporisation. In the search for alternatives, passive downdraught evaporative cooling pdec is. Pdf passive downdraught evaporative cooling system. Analysis and evaluation of a passive evaporative cool tower in conjunction with a solar chimney. Evaporative cooling is a very powerful method of passive cooling that can easily compete with conventional air conditioners in consciously designed buildings santamouris and asimakopolous, 1996. Evaporative cooling uses the fact that water will absorb a relatively large amount of heat in order to evaporate. A passive downdraft evaporative cooling pdec tower is a variation of a wind tower.
Passive cooling techniques to improve indoor thermal comfort. Champion cooler 3970 cfm 115v 2speed downdraft roof lowprofile contractor model evaporative cooler for 1820 sq. In direct evaporative cooling, the water content of the cooled air increases because air is in contact with the evaporated water. In this scheme the air was supplied via the central corridor and exhausted at the perimeter as indicated on figure 1. Assessment of passive downdraft evaporative cooling technique. In order to extend the use of evaporative cooling, a downdraft evaporative cool tower was integrated at the solar lab at asus school of architecture and landscape architecture. Implementation of natural downdraft evaporative cooling devices. Analysis of the system response of a spray passive downdraft. Passive down draft evaporative cooling air conditioning.
When the decrease in the dry bulb temperature is accompanied by an increase in the moisture content of the air, the process is commonly referred to as direct evaporative cooling. Passive cooling techniques to improve indoor thermal. Course contents evaporative coolers, often called swamp coolers, are cooling systems that use only water and a blower to circulate air. Integrated approach in building design for passive cooling. As previous studies heavily focused on the energy saving capability of a. Passive cooling systems use nonmechanical methods to maintain a comfortable indoor temperature and are a key factor in mitigating the impact of buildings on the environment. It works by using heat from the sun and employs both desiccant and evaporative. Improving their performance and broadening their use will therefore be environmentally and economically beneficial.
It comprises four simulation scenarios to see the system response and influence of indoor. The cool tower concept utilizes pressure differences stack effect to move air through the building. Passive downdraught evaporative cooling windtowers. Evaporative cooling has been applied in various forms for several centuries in different parts of the world, particularly in the middle east where various techniques have been employed over time to encourage air movement and cooling in buildings. The findings outlined in their paper show that this building, completed over 10 years ago, continues to satisfy expectations for a contemporary workplace of high quality that is simultaneously energy efficient also. The passive downdraft evaporative cooling system is an example of this process. Specializing in mastercool coolers and air conditioning parts and supplies. During this process, a large amount of heat is consumed by water as it evaporates. A detailed description of the design process, building configuration, environmental control system and thermal performance can be found in an earlier study completed by baird 2001. Pdec passive downdraught evaporative cooling acronymfinder. A passive downdraft evaporative cooling pdec tower is a component. Natural downdraft evaporative coolers, or cool towers, are devices.
Passive downdraft evaporative cooling is an old technique. Passive downdraft evaporative cooling with stack driven ventilation the cool air is supplied to the occupant space using passive down draft shaft with the help of mist micronisers and the stale air is exhausted using stack ventilation system as shown in the picture. This study is intended to evaluate the capability of a spray pdec system for space cooling. Additional information on the natural downdraft evaporative. Review of passive downdraught evaporative cooling technique.
The development of passive downdraught evaporative. The technique has significant architectural and engineering design implications, and involves the configuration of existing. An overview of passive cooling techniques in buildings. Overview of passive downdraft cooling systems using evaporative cooling. The design and performance of a passive downdraught evaporative cooling pdec system are reported.
These components are a modified form of wind towers. Direct evaporative cooling has long been demonstrated as an energy efficient,cost effective and no cfcs emission means for space cooling in hot dry regions. Passive direct evaporative cooling can occur anywhere that the evaporatively cooled water can cool a space without the assist of a fan. Passive evaporative cool tower study asu stardust center. Passive cooling techniques can reduce the peak cooling load in buildings, thus reducing the size of. The use of clay and porous ceramic in passive downdraught evaporative cooling has a track record in the vernacular architecture of many hot and dry. The work described here is a study aimed at validating the computational fluids dynamics cfd method using experimental data available from a prototype multistage system.657 406 832 67 19 791 938 664 572 876 970 330 899 1233 268 1636 1415 29 669 353 936 418 238 1186 21 601 1016 602 1233 1556 1062 999 414 1466 1097 548 586 1412 1044 591 520 998 525