Increasing temperature causes air vapor pressure to. Analysis of various designs of a desiccant wheel for. When combined with conventional cooling systems, desiccant dehumidification systems are a costeffective means of supplying cool, dry, filtered air. Lmn goes beyond simple software solutions, with integrations and training to drive your business forward. Every aspect of rotor dynamics, behavior, characteristics and physical parameters has been considered to maximize performance. Energy efficient humidity control for commercial and institutional buildings conference, new orleans, louisiana june 23, 1993. Trane engineers newsletter volume 344 providing insights for todays hvac system designer.
In calculating moisture load, absolute humidity is the basis used and not relative humidity. Dehumidification troubleshooting guide desiccant dehumidifiers. Preliminary findings on the performance of a new residential solar desiccant airconditioner daniel rowe 1, stephen white, mark goldsworthy, thorsten spillmann, roger reece 1, darren rossington 1, brian dolly 2, manny larre and richard thomson 1 csiro energy technology, 10 murray dwyer cct, mayfield west, nsw, 2300, australia, daniel. Solid desiccant air dehumidifier system is widely being used to supply dry air. According to one estimate, desiccant dehumidification could reduce total residential electricity demand by 25% or more1 in humid. Simulation of adsorption process in a rotary solid desiccant wheel. Estimating software provides standard processes to build cost models for executing jobbased work. A unit approximately one ounce is the amount of desiccant that will absorb at least three. This model has been used to conduct a comparative performance of desiccant wheel with effective and ordinary regeneration sector. Novelaire provides desiccant wheel design, desiccant wheels and energy conservation wheels for commercial air conditioning applications. Performance of desiccant wheel for low humidity drying. The current installation base of dri energy wheels. Mar, 20 a mathematical model for predicting the performance of a desiccant wheel with various wheel designs has been used by considering heat and mass transfer for both moist air and the desiccant material.
Typical operating conditions encountered in the cooling and heating mode of a total energy recovery unit. Comparative performance of desiccant wheel with effective and. Wheel rotor dryers provide the longest lasting desiccant medium on the market today and therefore require the lowest frequency of replacement than any other type of desiccant dryer. This desiccant dehumidification wheel test guide is intended to facilitate their use by certification labs and manufacturers. The authors would like to thank ron fiskum, doe program manager, office of. The section of silica gel is ruled by a great margin. They compared the performance of a desiccant wheel used in air. With this significant load reduction, the component integrated in solar hybrid desiccant airconditioning system can perform comfort cooling to area with high latent load such as hall, hyper market and commercial building.
This paper will only discuss the performance of desiccant wheel and the estimated drying process, while the collector performance, heat exchangers and other components not discussed. The wheel performance curves which help to determine the air outlet co nditions and coefficient of performance cop of the system are drawn for a wide range of wheel thic kness 0. Compared to refrigerated air dryers the cost of operation of desiccant dryers is fairly expensive therefore their use should be carefully considered. Theoretical and experimental analysis of desiccant wheel. The first edition of the dehumidification handbook was published in 1982 by cargocaire engineering corporation, an earlier name for what is now the dehumidification division of munters corporation. Reduction of regeneration energy of up to 30% reduction of up to 70% postcooling with cooler. The basic idea of the munters desiccant drying wheel rotor is very simple. The trane cdq desiccant wheel is used to enhance the dehumidification performance of a traditional cooling coil. Seibu giken dst ab, founded in 1985, is now a leading international supplier of desiccant dehumidifiers. An active desiccant wheel is very effective at removing moisture from the supply process air stream, but for every ton of latent heat m oisture removed, it adds more than one ton of sensible heat back into the supply air. Please also refer to the psychometric chart for various values referenced. Desiccant cooling technology resource guide cedengineering. Pdf performance evaluation of solid desiccant wheel. Process fan moves air stream that passes through desiccant wheel and is located in the dehumidifier housing.
This performance model relates the wheels design parameters, such as the wheel dimension, the channel size and the desiccant properties, and the wheels operating variables. Feb 01, 2010 instruction and discussion for energy modelers, building simulators, architects and engineers is a site for energy modelers, building simulators, architects, and engineers who want learn the basics, to advanced concepts of energy modeling. This takes energy to regenerate dry the wheel after it has absorbed moisture out of the building. All vendorsupplied parts are manufactured to munters exacting. Software provided by novel aire company is used to calculate outlet air conditions. Unfortunately, i keep seeing passive desiccant wheels installed and expected keep the building dry in all conditions. Desiccant wheel operating system there are two processes, namely the process of regeneration and dehumidification 10. Because titanium silica gel is a solid, insoluble desiccant, it is not. The program models the performance of a wide array of input parameters to ensure the proper selection of desiccant wheel size and type. There are two primary types of desiccant dehumidification. Desiccant dehumidification troubleshooting guide there are a number of things when dealing with desiccant dehumidifiers that have to be present so dry air can be achieved. The air leaves the rotor much drier than when it entered. The first edition of the dehumidification handbook was published in 1982 by cargocaire engineering corporation, an earlier name for what. The performance of the desiccant wheel is increased by up to 30% purge sector benefits.
The modeling results are obtained as the changes of the outsideprocess and building exhaustregeneration air conditions along the wheel depth and the wheel rotation. In this paper, experimental data collected in a test facility equipped with a dcs, are used to develop regression models for predicting the dehumidification and thermal performance of a desiccant. Dri, an iso certified company is a global provider of components, products and systems for energy recovery, iaq, fresh air treatment, evaporative cooling. It is assessed that the marketplace embraces huge openings for the development and will step ahead a strong development track over the forecast period. Two programs in the script language are made for process and.
This desiccant wheel is capable of condensing water at 0. Formulation and validation of a twodimensional steady. Each different arrangement of desiccant wheel has been modelled in tas systems to match the performance. Desiccant rotors heat wheels energy recovery wheels. Desiccant wheels are rotary desiccant dehumidifiers used in air conditioning and drying. Solid desiccant assisted cooling and dehumidification systems are becoming very popular nowadays for maintaining the required thermal comfort in different residential and industrial cooling applications. A thermal wheel, also known as a rotary heat exchanger, or rotary airtoair enthalpy wheel, or heat recovery wheel, is a type of energy recovery heat exchanger positioned within the supply and exhaust air streams of an airhandling system or in the exhaust gases of an industrial process, in order to recover the heat energy. Other variants include enthalpy wheels and desiccant wheels. International journal of advanced research in issn. The active desiccant wheels low rotational speed limits the sensible heat transferred between the process and regeneration airstreams. The software estimates energy costs and hu midity levels. Desiccant dehumidifiers and heat energy recovery wheels product brochures, research and white papers seibu giken america. A calciumrich montmorillonite, desi paks layered structure attracts and binds water molecules to its vast inner and outer surface area.
Sep 14, 2000 desiccant dehumidification technology provides a method of drying air before it enters a conditioned space. An additional filter on the outlet catches the desiccant dust that is generated from the constant movement of the desiccant beads against one another caused by flow of air through the dryer. At the heart of these dehumidifiers is a patented desiccant wheel. Apr 22, 2014 a mathematical model for predicting the performance of a desiccant wheel with effective regeneration sector has been used. Liquid desiccant vs desiccant wheel dehumidification whats.
Although some manufacturers provide a means for estimating the performance at altitude based on standard conditions, there is no methodology that. Performance investigation of an internally cooled desiccant wheel. Desiccant dehumidifiers are especially wellsuited for removing moisture from air at a low temperature and low humidity level. A desiccant wheel with active regeneration gas or electric heat can remove moisture very, very effectively. The current installation base of dri energy wheels in north america runs in thousands. Performance evaluation of solid desiccant wheel regenerated by. A mathematical model of desiccant wheels is established and validated by experimental results. It is also used to draw the performance curves of the desiccant wheel to quantify the.
Dri, an iso certified company is a global provider of components, products and systems for energy recovery, iaq, fresh air treatment, evaporative cooling, humidification, rh control and green buildings. Desiccant dehumidifiers, manufactured by seibu giken dst ab. Result and discussion based on results obtained from dw software, trend of factors affecting desiccant wheel performance is plotted against evaluating parameters predicting desiccant wheel general behavior. Active desiccant behavior approximates a constant enthalpy process. Wheel performance the desiccant wheels are designed to. A mathematical model for predicting the performance of liquid.
Prepared for proceedings of epris electric dehumidification. It was found that for all the cases considered in this study like rotation of wheel, regeneration temperature, velocity and ambient moisture. The unique g3ma passive desiccant dehumidification wheel patent pending has the ability to be regenerated with the 50% rh room return air allowing for substantial moisture removal through dehumidification of the fresh air being supplied to the room. Twowheel desiccant dehumidification system, federal technology alert applications engineering. Commercial and residential air solutions novelaire. It is a product of more than 20 years of experience gained at the national renewable energy laboratory s nrel desiccant research facilities. In fact, desiccant wheel performance strongly depends on inlet airflow conditions and on the revolution speed. Performance comparison between enthalpy recovery wheels. The performance of the desiccant wheel is critical to the viability of the desiccant cooling process. Selection of desiccant equipment at altitude request pdf. The performance of desiccant wheels for desiccant air. Unlike totalenergy wheels, howeve r, active desiccant wheels rotate very slowlybetween 10 and 30 rotations per hour. Figure 8 shows the system performance for this unit. We are having trouble keep a handle on the humidity level in the.
Dst is currently represented in over 40 countries throughout the world. In this article, we summarize a recent federal technology alert on two wheel desiccant dehumidification systems, provided by the federal energy management program. It is used most commonly in the construction industrybut can also apply to other industries that conduct work on a project basis and need to determine likely costs of completing the work. Dec 28, 2016 the design of air handling units based on this technology is quite complex because of the difficulties in predicting the performance of the desiccant wheel, which is the crucial component of the system. The wheel is configured in series with the coil see figure 1 such that the regeneration side of the wheel is located upstream of the coil a nd the process side of the wheel is located downstream of the coil. Industrial desiccant dehumidification system munters. Implementation of galssvm modelling approach for estimating. Its performance can be evaluated by simulating it with trnsys simulation software. Figure 2 shows the schematic and the psychrometric process for a desiccant dehumidification system with an active desiccant wheel. Desiccant dehumidification rotors ecodry desiccant. Sudchemies desi pak bentonite clay desiccants are an effective and economical desiccant option. Preliminary findings on the performance of a new residential. The wheel technology does not employ desiccant beads, but pure molecular sieve desiccant that is permanently bonded to the airpassing corrugations of the wheel.
Please note that a unit of desiccant refers to its drying capacity, not its volume. Evaluation and optimization of solar desiccant wheel performance. Implementation of galssvm modelling approach for estimating the performance of solid desiccant wheels article in energy conversion and management 127. Using the software, the performance of a rotary dehumidifier is studied. Performance evaluation of solid desiccant wheel regenerated. The air leaves the cooling coil ca at a very high relative humidi ty, typically about 97 percent rh. This document shows how tas systems can comply with the rated performance of desiccant based dehumidification systems, as documented by trane in the engineering newsletter volume 344. Simplified models for the performance evaluation of. This paper will only discuss the performance of desiccant wheel and the estimate drying process, while the collector performance, heat exchangers and other components not discussed. Process fan moves air stream that passes through desiccant wheel. Munters desiccant dehumidification systems remove moisture from the air by using a desiccant. Desiccant wheels are commonly used to dehumidify air in airconditioning system to reduce the energy consumption. There have been a number of efforts to develop improved desiccant materials for desiccant wheels. Simplified models for the evaluation of desiccant wheels.
The performance of desiccant wheel dw, coated with a desiccant material to absorb the moisture of the air, significantly controls the system size, capacity, and cost. Desiccant dehumidifiers and heat wheels products seibu. The global desiccant wheel market is very modest on the footings of products and facilities presented. To maximize moisture collection, the wheel rotates. Air is blown though the rotor structure and the humidity in the air is absorbed by the desiccant impregnated in the honeycombe media that forms the rotor structure. According to one estimate, desiccant dehumidification could reduce total residential electricity. Give your dehumidifiers the winning age with dri desiccant dehumidifying rotors language. Successful login as a registered user will allow you to populate project header information, use the g3ma sizing feature, printsave a pdf report and develop a dri quote for the calculated product. Performance of desiccant wheel for low humidity drying system. Dri has a worldwide network of sales offices all over india, usa. Software selection program for a more comprehensive analysis of performance, please consult the factory with the model selection software program. I am looking for some information on a good desiccant wheel to help remove mositure from a testing lab here in minnesota.
Rotor source leads the industry in supplying oem and contractorinstalled heat and mass transfer wheels for hvac applications. The numerical software was used to carry out flow simulation. Its parent factory is one the worlds largest manufacturer of ahri certified energy recovery wheels. Home products desiccant dehumidification active dehumidification wheels. The desiccant calculation chart below is specifically for estimating how much clay or silica gel desiccant you need. The different effects of substrate, air mixing, and rotation speed on the performance of enthalpy. Desiccant dryers ten lessons learned compressed air best. Desiccant cooling systems are energy efficient and environmentally benign. Desiccant calculation chart how much desiccant do you need. Worldclass test facilities for performance evaluation of enthalpy wheels and desiccant wheels. The objective of this study was to design, test and analyse the performance of a novel tubeshell, internally watercooled desiccant wheel.
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