Climate Control System Research Articles

Who steals my identity steals trash

I've thought about this identity theft issue, and I've decided not to worry about it. My blasé feelings come from careful consideration of the consequences, not to me, but to the thief, of anyone who steals the identity of an academic scientist.

CLIMATE CONTROL BASED ON TEMPERATURE MEASUREMENT IN THE ANIMAL-OCCUPIED ZONE OF A PIG ROOM WITH GROUND CHANNEL VENTILATION

It is known that there can be a significant temperature difference between the position of the climate controllersensor (room temperature) and the animal-occupied zone (AOZ) in a pig room. This study explores the advantages of usingAOZ temperature in climate control. The objectives were: (1) to evaluate a current climate control system in a practical roomwith ground channel ventilation for weaned piglets by comparing AOZ and room temperature, and (2) to determineadvantages of control of the heating system based on AOZ temperature by a model-based predictive (MBP) controller.Comparison of AOZ and room temperature showed that during the first 10 days of the two experimental batches, AOZtemperature was lower and showed greater fluctuations than room temperature, most likely due to the switching of the heatingsystem (on/off). Animals close to the sensor could disturb the AOZ measurement. This was not the case during colder nights,when animals moved away from the sensor and the measured AOZ temperature was a good indicator of the air temperaturearound the animals. The data for those periods were suitable for use in this climate control study, but when applying the systemin practice the disturbing effect needs to be prevented by better protection of the AOZ sensor. For the second objective, thecourse of the AOZ temperature was modeled based on data for five nights when the heating switched on and off several times(goodness of fit Rt 2 = 0.77). One of the models was integrated in a simulated MBP controller that uses the model to predictfuture AOZ temperature; the controller switches the heating system on before the AOZ gets too cold and off before it gets toowarm. The simulated AOZ temperature was more stable during an 11 h cold period; the standard deviation was reduced from0.44C to 0.18C.

Emerson Electric Co.

AbstractInstruments and Related Products (MIC: 11.15 SIC: 3621 NAIC:335312)Emerson Electric designs and manufactures electrical, electromechanical and electronic products, systems and services. The Process Control segment makes process management products. The Industrial automation (IA) segment provides industrial motors, drives, controls and equipment for IA markets. The Electronics and Telecommunications segment designs, manufactures, installs and maintains power products for network‐dependent clients. The Heating, Ventilation and Air Conditioning segment engineers and manufactures climate control components and systems. The Appliance and Tools segment provides motors, controls and components for appliance, industrial and comfort control applications.

Predicting human thermal comfort in a transient nonuniform thermal environment.

The National Renewable Energy Laboratory has developed a suite of thermal comfort tools to assist in the development of smaller and more efficient climate control systems in automobiles. These tools, which include a 126-segment sweating manikin, a finite element physiological model of the human body, and a psychological model based on human testing, are designed to predict human thermal comfort in transient, nonuniform thermal environments, such as automobiles. The manikin measures the heat loss from the human body in the vehicle environment and sends the heat flux from each segment to the physiological model. The physiological model predicts the body's response to the environment, determines 126-segment skin temperatures, sweat rate, and breathing rate, and transmits the data to the manikin. The psychological model uses temperature data from the physiological model to predict the local and global thermal comfort as a function of local skin and core temperatures and their rates of change. Results of initial integration testing show the thermal response of a manikin segment to transient environmental conditions.

An electronic nose based on solid state sensor arrays for low-cost indoor air quality monitoring applications

The occurrence of illnesses related with poor ventilation has driven an increasing attention towards indoor air quality monitoring. In buildings equipped with climate control systems, the diseases related to the air quality can be significantly reduced if smart intervening procedures, aiming to control the concentration of pollutants in the indoor air, can be implemented in the heating, ventilation air conditioning unit. When reliable information about both the indoor and outdoor air quality is made available, the climate control system can provide the most appropriate amount of ventilation, ensuring safe and comfortable living conditions. In this paper, a dedicated, miniaturized, low-cost electronic nose based on state-of-the-art metal oxide sensors and signal processing techniques was developed. The proposed device is targeted to the quantification of carbon monoxide and nitrogen dioxide in mixtures with relative humidity and volatile organic compounds by using an optimized gas sensor array and highly effective pattern recognition techniques. The electronic nose was tested in an environment reproducing real operating conditions. Exploiting the unique response patterns of the different sensors in the array and the capability of a simple fuzzy-logic system it was possible to identify and discriminate concentrations as low as 20 ppb for NO2 and 5 ppm for CO in the test gas environment, allowing to reach the necessary sensitivity towards the target pollutants together with the selectivity towards the typical interfering gas species.

Emerson Electric Co.

AbstractInstruments and Related Products (MIC: 11.15 SIC: 3621 NAIC:335312)Emerson Electric designs and manufactures electrical, electromechanical and electronic products, systems and services. The Process Control segment makes process management products. The Industrial automation (IA) segment provides industrial motors, drives, controls and equipment for IA markets. The Electronics and Telecommunications segment designs, manufactures, installs and maintains power products for network‐dependent clients. The Heating, Ventilation and Air Conditioning segment engineers and manufactures climate control components and systems. The Appliance and Tools segment provides motors, controls and components for appliance, industrial and comfort control applications.

An electronic nose based on solid state sensor arrays for low-cost indoor air quality monitoring applications

The occurrence of illnesses related with poor ventilation has driven an increasing attention towards indoor air quality monitoring. In buildings equipped with climate control systems, the diseases related to the air quality can be significantly reduced if smart intervening procedures, aiming to control the concentration of pollutants in the indoor air, can be implemented in the heating, ventilation air conditioning unit. When reliable information about both the indoor and outdoor air quality is made available, the climate control system can provide the most appropriate amount of ventilation, ensuring safe and comfortable living conditions.In this paper, a dedicated, miniaturized, low-cost electronic nose based on state-of-the-art metal oxide sensors and signal processing techniques was developed. The proposed device is targeted to the quantification of carbon monoxide and nitrogen dioxide in mixtures with relative humidity and volatile organic compounds by using an optimized gas sensor array and highly effective pattern recognition techniques. The electronic nose was tested in an environment reproducing real operating conditions. Exploiting the unique response patterns of the different sensors in the array and the capability of a simple fuzzy-logic system it was possible to identify and discriminate concentrations as low as 20ppb for NO2 and 5ppm for CO in the test gas environment, allowing to reach the necessary sensitivity towards the target pollutants together with the selectivity towards the typical interfering gas species.

Toward simulation-based design

This paper discusses the technologies needed to support the application of simulation-based design. Emphasis is placed on the technical components that must be added to existing CAD and CAE tools to enable the application of simulation-based design. These components include a simulation model manager, simulation data manager, adaptive control tools and simulation model generators. The application of these technologies to automotive climate control system design is demonstrated.

CFD for model-based controller development

This paper outlines a novel approach to model and control the internal dynamics of energy and mass transfer in an imperfectly mixed fluid. The essential element in the approach lies in the extension of a complex CFD simulation model with a simplified, low-order representation of the process using a mathematical identification technique. The reduced-order model that characterises the dominant modes of dynamic behaviour forms an excellent basis for on-line model-based control purposes. Most control algorithms are designed based on experimental time-series data, unlike the others this paper discusses a methodology to use numerical predictions for controller development. This has important practical advantage for control applications especially when experimentation is difficult or in some extreme cases impossible. Furthermore, the inspiration of using numerical predictions instead of experimental time-series data allows designing virtual climate control systems, which launches new possibilities to large number of applications. In this paper, the general methodology will be elaborated using multiple-input–multiple-output (MIMO) ventilation system, and later on the approach will be applied for a single-input–single-output (SISO) ventilation system.

Sustainable climate control for historic buildings in subtropical climates

To preserve both cultural collections and historical buildings that house them, a technologically simple yet robust climate control system was installed in the Historic Archive of the Canary Islands. The archive is located in a municipal building, a late nineteenth century massive masonry building in the city of La Laguna, on Tenerife Island, Spain. The system was designed to maintain the RH level necessary for preventing microbial activities on collections in cultural institutions, by operating residential‐type ventilators and a convective heater under a humidistatic control. We have confirmed that the system not only successfully eliminated events of high relative humidity but also stabilized the climate. The annual temperature variation was significantly reduced, although daily variations increased. The room's moisture content was reduced to less than that of the outside, and microbial activities were reduced in the environment. The system was simple to install and inexpensive to operate.

IntelliGrow: a greenhouse component-based climate control system

A new greenhouse climate control system has been constructed with the objective of decreasing energy consumption while maintaining, or even increasing, plant production. The system is based on the use of mathematical models for estimating the absorption of irradiance, leaf photosynthesis and respiration. The model builds on a general leaf model that with a few modifications can be used for different greenhouse crops. The temperature, which was controlled according to the natural irradiance, was allowed to vary considerably more than in a standard climate. Under low light conditions, energy use was reduced because the temperature was lowered. In contrast, when irradiance is higher, the plants seem able to utilize both a higher temperature and CO 2. During nighttimes the temperature was lower than in standard climate. The thermal screens were used according to a screen simulation system. The system balances the energy costs saved via isolation against the production loss caused by the decrease in irradiance. A six-month trial of the system resulted in energy savings ranging from 8% in late spring (April–June) to 40% in early spring (March–May). During the winters 1997–98 and 1998–99 the accumulated energy savings per season varied between 20% and 38% at two different locations in Denmark.

Climate control in vacuum dryers for convective heat transfer

The first part of this contribution determined the demands on climate control in vacuum drying kilns that are necessary to achieve the final moisture content variation stipulated in the European Drying Group (EDG) proposal on wood drying quality standards. In this second part of the contribution, these demands are compared with measurements of actual climates and the resulting final moisture content in vacuum kilns during industrial production. The measurements show that none of the studied industrial vacuum kilns are capable of controlling climate with acceptable accuracy. The variations in drying climate lead to large variations in final moisture content and reduced production capacities. Drying quality and drying capacity would be greatly increased with improved kiln design and improved climate control systems. Critical factors in kiln design and climate control system design necessary to maintain a controlled drying climate are listed.

A nonlinear feedback technique for greenhouse environmental control

Climate control for protected crops brings the added dimension of a biological system into a physical system control situation. The plants in a greenhouse impose their own needs, significantly affect their ambient conditions in a nonlinear way, and add long-time constants to the system response. Moreover, the thermally dynamic nature of a greenhouse suggests that disturbance attenuation (load control of external temperature, humidity, and sunlight) is far more important than is the case for controlling other types of buildings. This paper presents a feedback–feedforward approach to system linearization and decoupling for climate control of greenhouses and more specifically for the operation of ventilation/cooling and moisturizing. The proposed method consists of three parts: (a) a model-based feedback–feedforward compensation of external disturbances (loads) on the basis of input–output linearization and decoupling; (b) the transformation of user-defined desired settings for temperature and humidity into feasible controller setpoints, taking into account the constraints imposed by the capacities of the actuators and the psychrometric laws; and (c) additional PI outer loops to compensate for model uncertainties and deviations from expected disturbances (weather). Moreover, some tuning tests lump together several physical system parameters to be easily identified, and the method guarantees accuracy in setpoint tracking while simplifying stability issues. The proposed method is applicable to any air-conditioning system and is expected to gain wide acceptance in modern climate control systems.

Climate control in vacuum dryers for convective heat transfer

The European Drying Group (EDG) proposal on a wood drying quality standard defines demands on final moisture content variation of the dried wood. The final moisture content variation will depend on material parameters as well as the production process and the wood will always show a natural moisture content variation after drying. Thus the drying process has to be defined well enough to allow for the natural moisture content variation in order to fulfil the demands of the drying standards. As the average equilibrium moisture content of the wood in a vacuum drying kiln with pure steam atmosphere is determined by the pressure and the temperature, the demands on the climate control system to fulfil the demands of the drying standard can be calculated with regard to the natural moisture content variation of the wood. In the first part of this contribution the demands on climate control in vacuum dryers are calculated based on the EDG-standard and the natural moisture content variation. In the second part of the contribution the demands on climate control are compared with climate and moisture content measurements from industrial production in vacuum kilns. Critical factors in kiln design and climate control system design necessary to maintain a controlled drying climate are listed.

Commentary

HIGHLIGHTED TOPICSCommentaryGary C. Sieck, Gary C. Sieck Journal of Applied Physiology, EditorPublished Online:01 Jun 2002https://doi.org/10.1152/japplphysiol.00240.2002MoreSectionsPDF (24 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat The first Highlighted Topics article selected for this issue of the Journal of Applied Physiology, “Role of IL-6 in LPS-induced nuclear STAT3 translocation in sensory circumventricular organs during fever in rats,” by Harré and colleagues (p. 2657–2666), applies a new molecular neuroanatomic approach to look at the location of cytokine-induced genomic activation in the brain. Cytokines released into the systemic circulation are thought to act on the brain at the circumventricular organs (CVOs), sites that lack a blood-brain barrier. For nearly 20 years, investigators have believed that sensory CVOs [e.g., the vascular organ of the lamina terminalis (OVLT) and the subfornical organ (SFO)] are involved in fever induction pathways (Blatteis et al., Brain Res Bull 11: 519–526, 1983); however, no molecular evidence has clearly supported this hypothesis. The cytokine interleukin-6 (IL-6) is regarded as an endogenous mediator of lipopolysaccharide (LPS)-induced fever. Cells that are activated by IL-6 respond with nuclear translocation of the transcription factor STAT3. Harré and colleagues used STAT3 immunohistochemistry to analyze the exact location of this cytokine action on the brain. After systemic LPS and IL-6 treatment, in doses proven to induce fever responses, the only brain structures that responded with a marked nuclear STAT3 translocation were the OVLT and the SFO. This nuclear STAT3 translocation was observed 2 h after LPS treatment, whereas it occurred only 1 h after IL-6 application, reflecting the time delay for LPS induction of the cytokine IL-6. These authors present the first molecular evidence for an IL-6-induced STAT3-mediated genomic activation of OVLT and SFO cells and support the proposed role of these brain areas as sensory structures for humoral signals created by the activated immune system. In addition, STAT immunohistochemistry may reveal the locations of cytokine-specific genomic activation in the brain with distinct STAT molecules as neuroanatomic markers.The second Highlighted Topics article featured in this issue, “Ambient temperature for experiments in rats: a new method for determining the zone of thermal neutrality,” by Romanovsky and colleagues (p. 2667–2679), is an Innovative Techniquesarticle, which examines current methods and proposes a new one for finding the thermoneutral zone (TNZ) in the rat. A common misperception is that an animal has the same TNZ in different experimental setups. In reality, the TNZ strongly depends on the physical environment and varies widely across experimental conditions. However, current methods for determining the TNZ are applicable only to a limited set of experimental conditions and require elaborate equipment. Romanovsky and colleagues developed a novel, broadly applicable approach that rapidly determines whether given conditions are neutral, subneutral, or supraneutral for a given animal. On the basis of the current definition of TNZ (the range of ambient temperature at which body core temperature regulation is achieved only by control of sensible heat loss), the authors proposed three criteria of thermoneutrality: 1) the presence of high-magnitude fluctuations in skin temperature of body parts serving as specialized heat exchangers with the environment (e.g., rat tail), 2) the closeness of skin temperature to the median of its operational range, and 3) a strong negative correlation between body core and skin temperatures. The authors used thermocouple thermometry and liquid crystal thermography to find the TNZ in five rat strains. Under the conditions tested (no bedding or filter tops, no group thermoregulation), the temperature range of 29.5–30.5°C satisfied all three TNZ criteria in Wistar, BDIX, Long-Evans, and Zucker lean rats. Fat Zucker rats had a slightly lower TNZ (28.0–29.0°C). Skin thermometry or thermography is a definition-based, simple, and inexpensive technique, handy for determining whether given conditions are neutral, subneutral, or supraneutral for a given animal. Although tested only in the rat, the same approach is likely to be applicable to all endothermic animals that possess specialized heat-exchange organs. It may be used to solve a variety of problems, ranging from standardization of biomedical experiments to optimization of housing for agricultural animals to development of automatic climate control systems for human patients.FOOTNOTES10.1152/japplphysiol.00240.2002This article has no references to display. Download PDF Previous Back to Top Next FiguresReferencesRelatedInformation More from this issue > Volume 92Issue 6June 2002Pages 2656-2656 Copyright & PermissionsCopyright © 2002 the American Physiological Societyhttps://doi.org/10.1152/japplphysiol.00240.2002History Published online 1 June 2002 Published in print 1 June 2002 Metrics

High-Density Remote Storage

This article describes a high-density off-site book storage facility operated by the Ohio State University Libraries. Opened in 1995, it has the capacity to house nearly 1.5 million items in only 9,000 square feet by shelving books by size on 30-foot tall shelving. A sophisticated climate control system extends the life of stored materials up to 12 times. Materials are retrieved upon request of patrons and delivered to the Main Library three times daily.

The physiologically controlled air conditioning system

Today’s climate control systems are technically advanced but, until now, even fully automatic systems have only been able to control temperature. All other aspects have been controlled by pre-determined values. By controlling temperature, which is usually measured at only one point in the vehicle interior, passengers’ comfort needs cannot be fully met, because it is the temperature actually felt by a person that is the decisive factor in his or her experience of comfort. This in turn depends not only on air temperature and speed but also to a large extent on humidity levels and sunlight. In order to provide optimal climate control, the temperature actually felt must be taken into account.

Behr’s New PEP

The goal of Behr’s development programme is to increase the car driver’s comfort and to make the engine cooling and climate control systems faster and more efficient. The particular benefits of the new Product Evolution Process (PEP) are emphasised below.

INTEGRATED PREDICTIVE ADAPTIVE CONTROL OF HEATING, COOLING, VENTILATION, DAYLIGHTING AND ELECTRICAL LIGHTING IN BUILDINGS

The present energy consumption of European Buildings is higher than necessary, given the developments in control engineering. Optimization and integration of smart control into building systems can save substantial quantities of energy on a European scale while improving the standards for indoor comfort. Many tools are available for the simulation of one or some of the following aspects: (a) heating, cooling and indoor thermal comfort, (b) ventilation and indoor air quality, (c) daylighting, electrical lighting and light quality, (d) installations, local control and fault detection, (e) Genetic optimized Neuro-Fuzzy control. The interaction between these aspects, however, is very relevant and cannot be neglected. Therefore, an integrated software tool is required. TNO together with the University of Delft develops such an integrated tool. This paper describes the first results of the utilization of this tool and the development of an integrated, predictive, adaptive building system for indoor climate control.

Occupational exposure to volatile anaesthetics: epidemiology and approaches to reducing the problem.

Long term occupational exposure to trace concentrations of volatile anaesthetics is thought to have adverse effects on the health of exposed personnel. In contrast with halothane--an agent likely to cause mutagenic effects and proven to be teratogenic--isoflurane and enflurane have not so far been proved to have adverse effects on the health of personnel exposed long term. Data on the newer agents sevoflurane and desflurane are limited. Since possible health hazards from long term exposure to inhalational anaesthetics cannot yet be definitively excluded, many Western countries have established limits for exposure. These usually range from 2 to 10 ppm as a time-weighted average over the time of exposure. A number of investigations have demonstrated that, in operating theatres with modern climate control and waste anaesthetic gas scavenging systems, occupational exposure is unlikely to exceed threshold limits. However, occupational exposure from the use of volatile agents in operating theatres with poor air control--especially during bronchoscopy procedures in paediatric patients--remains a source of concern. This also holds true for both postanaesthesia care units (PACU) and intensive care units (ICU) lacking proper air conditioning and waste gas scavengers. To minimise occupational exposure to volatile anaesthetics, all measures must be taken to provide climate control and properly working scavenging devices, and ensure sufficient personal skill of the anaesthetist, e.g. during inhalational mask induction. Furthermore, low-flow anaesthesia should be used whenever possible. The sole use of intravenous drugs such as propofol instead of volatile agents, were this possible, would eliminate occupational exposure, but may result in environmental pollution by toxic metabolites (e.g. phenol).