Heating, Ventilating, Air Conditioning & Refrigeration

This project aims to design a central air
conditioning system for Pharmaceutical Factory.
The design focuses on the air conditioning system
for Pharmaceutical facility, by making complete
cooling & heating load calculations, selection of
equipments suitable for the central air
conditioning system (such as chillers, handling
units, pumps ………… etc), airduct network
for the central air conditioning system and water
pipe network for the air handling units.

--- --- Description: --- ---
--- Technical field: ---
[0001] The present invention generally relates to heating
devices for space heating in homes and offices, and
particularly an improved radiator operating on the principle
of heat transfer by means of a continuous evaporation
and condensation of a fluid.
--- Prior art: ---
[0002] In the technical field of heating devices, in particular
for civil and domestic uses, there are known devices
which activate a transfer of heat to a surrounding
space by means of a continuous evaporation and condensation
of an internal fluid. These devices are known
in the art under the name of "heat pipes".
[0003] Generally, a heat pipe is formed of a sealed unit
containing a small quantity of a liquid in partial vacuum.
In a heat pipe, heat is absorbed through evaporation of
the liquid and given off through the condensation of the
vapour.
[0004] The application of heat pipes in a heating system
for civil and domestic use is known from document
GB 2 178 156 A. This document discloses a central heating
system comprising a heat source, a forward and return
fluid conduit in which a heat carrier fluid, e.g. water,
is circulated in closed circuit with the heat source and
one or more heatable panels which are arranged in a
vertical plane and are removably supported by the conduits,
wherein a part of the outer surface of each panel
is adapted to be placed in contact with a surface of the
conduit. The heatable panels form a sealed unit enclosing
a small quantity of volatile liquid, preferably in vacuum.
As contact is made between the panel and the conduit
there is a transfer of heat via the metal to metal surface
contact. The liquid contained in the panel absorbs
heat from the heat carrier fluid, is converted into a vapour,
rises to the top of the panel, condenses by giving off heat
to the space to be heated, and finally runs back down to
the bottom of the panel to begin again the evaporation
and condensation cycle. Another heat pipe radiator
known from JP2003130378.
[0005] The advantage of a heating system of this kind
consists in that it is versatile and inexpensive. In fact, the
heating system is adaptable to different heating requirements
because the panels can be placed in the most
convenient arrangement and removed when they are unnecessary
or when they require maintenance. These operations
can be easily and readily carried out also by an
unskilled person, without requiring an operation on the
closed circuit of the heating system.
[0006] However, in a heating system of the kind mentioned
above, there is the problem that the panels forming
the heat pipes lack stability when they are placed in position.
In an effort to solve this problem, the lower part of
the panels which is supported by the conduit is in the
shape of an inverted frustrum in cross section. However,
this solution to this problem has proved to be inadequate
and, moreover, is expensive because it requires a special
conformation of the conduit.
[0007] Accordingly, there is need for an improvement
in the installation of the heat pipes onto a conduit in which
the heat carrier fluid is circulated.

This chapter describes the method of a field study on the thermal comfort of occupants in a medium sized air-conditioned office building located in Sydney’s inner west and characterized by a subtropical climate. This study is a new approach to the indoor environment in office buildings which adopt the adaptive air-conditioning model in moderate, hot and humid, and cold climatic districts.

Between the techniques of climatic chamber and field study methodologies for thermal comfort experiments, a hybrid research design that combines both approaches may enhance the value of collected data by using typical buildings as field study while controlling the indoor environment in the same way as a climate chamber.
This research adopts the longitudinal method in data collection, studying a certain number of subjects over many visits. Therefore, the repetition of the observations from an individual correlates and validates the results under constant conditions.

İklimlendirme sistemlerinde mahal havasının istenen üretim veya konfor şartlarına gelebilmesi için, geçirmiş olduğu termodinamik süreçler nedeniyle özelliğini yitirmesinden dolayı değiştirilmesi yani yerine temiz hava alınıp tekrar mahal şartlarına getirilmesi gerekmektedir. Bu durum sisteme ek bir yük getirmekte ve mahal havası atık ısı olarak dışarı atılmaktadır. Oysaki ısı geri kazanım sistemleri kullanarak atık ısıların %25 ile %90 arasındaki kısmının geri kazanılması mümkündür. HVAC sistemlerinde bu oran optimum çözümlü uygulamalar için %35 ile %80 aralığındadır. İklimlendirme sistemlerinde kullanılan ısı geri kazanım cihazları, dış şartlarda alınan taze havanın egzoz havası yardımı ile ön ısıtılmasını (soğutulmasını) sağlayarak, taze havanın entalpi ve sıcaklığını, iç hacim şartlarına yaklaştırmaktadır. Ancak bu tip sistemlerde enerji başka bir sistemden alınırsa, ısı geri kazanımı olmaz. VDI 2071 e göre kütlenin transferi ısı geri kazanımı değildir. Yani hava karıştırılarak ısı geri kazanımı yapılamaz.

(Kaeltetechnik-Komponenten bzw. Kaelteanlagenbau-Bauteile) + Abkuerzungen aus der Heizungstechnik + Abkuerzungen aus dem Sanitaer-Bereich + Abkuerzungen aus Raumlufttechnik, Klimatechnik, Kaeltetechnik (Kaelteanlagenbau) + Wörterbuch für Mechatroniker/-Kältetechnik (+ Klimatechnik) Englisch-Deutsch (30000 Begriffe) + german-english (30000 Begriffe) zu bestellen unter:

This thesis includes the testing of different refrigerants in order to calculate coefficients of performance of different refrigerants. This project involves the detailed study of actual and theoretical coefficients of performance of six different refrigerants which are R 11, R 12, R22, R 23, R 134a and R 407a. These refrigerants are extensively used for domestic and industrial purpose. These refrigerants are being tested in this study depending upon two factors which are Coefficient of Performance and Environmental Parameters. Afterwards these coefficients of performance are compared with actual coefficients of performance calculated after experiments. This comparison of Coefficient of Performance helps in determining the best performing refrigerant in Refrigeration Industry. The results show that R 407a has maximum COP of 4.6 as compared to COP’s of other five refrigerants. Two new concepts have been introduced i-e R 407a and Inverter compressor Technology. Deploying these concepts, we can achieve refrigeration cycle having least environmental hazards and lesser electricity consumption and enhanced performance.
Key words
Coefficient of Performance (COP), Inverter compressor, Environmental Hazards, Refrigerants

Der Kachelofen mit seinen attraktiv gestalteten Ofenkacheln ist für die Erforschung spätmittelalterlicher und neuzeitlicher Wohnkultur in Mitteleuropa von grosser Bedeutung. Die vorliegende Publikation behandelt sowohl den Kachelofen als «Heizung des Mittelalters» als auch seine Bestandteile, die Ofenkacheln. Basis bildet eine umfassende Systematisierung der Ofenkeramik im deutschsprachigen Raum, bei der die Vielfalt der existierenden Kacheltypen aus der Schweiz, Deutschland, Österreich und Liechtenstein in Text und Bild sowie mit einem Glossar in 17 Sprachen behandelt werden. Das Buch präsentiert zudem den aktuellen Stand der Kachelofenforschung in der Schweiz und den Nachbarländern, die Herstellungstechnik von Ofenkacheln und das kulturgeschichtlich wichtige Thema der «Rekonstruktion». Daneben wird der Wert von Bildquellen und von Ofenmodellen diskutiert und die grösste Sammlung von Ofenmodellen in der Schweiz vorgestellt. Die umfangreiche Bebilderung macht das Buch auch für archäologisch und kulturhistorisch interessierte Laien im In- und Ausland sehr attraktiv. Im Gegensatz zur Keramik fehlte für die Ofenkeramik bisher eine überregionale Bearbeitung, ein «Leitfaden». Die vorliegende Publikation schliesst diese Lücke für den deutschsprachigen Raum.

The change of weather conditions and occupancy schedules makes heating ventilating and air-conditioning (HVAC) systems heavily dynamic. The mass and thermal inertia, nonlinear characteristics and interactions in HVAC systems make the control more complicated. As a result, some conventional control methods often cannot provide desired control performance under variable operating conditions. The purpose of this study is to develop control methods to improve the control performance of HVAC systems. This study focuses on optimizing the airflow-pressure control method of air side economizers, identifying robust building pressurization controls, developing a control method to control outdoor air and building pressure in absence of flow and pressure sensors, stabilizing the cooling coil valve operation and, return fan speed control. The improvements can be achieved by identifying and selecting a method with relatively linear performance characteristics out of the available options, applying fans rather than dampers to control building pressure, and improving the controller’s stability range using cascade control method. A steady state nonlinear network model, for an air handling unit (AHU), air distribution system and conditioned space, is applied to analyze the system control performance of air-side economizers and building pressurization. The study shows that traditional controls with completely interlinked outdoor air, recirculated air, relief air dampers have the best control performance. The decoupled relief damper control may result in negative building static pressure at lower outdoor airflow ratio and excessively positive building static pressure at higher outdoor airflow ratio. On the other hand, return fan speed control has a better controllability on building pressurization. In absence of flow and pressure sensors fixed interlinked damper and linear return fan speed tracking control can maintain constant outside air ratio and positive building pressure. The cascade control method is applied to improve the stability of cooling coil valve operation in single zone air handling unit systems, and return fan speed for building pressure control. The system dynamic response is studied using root locus analysis. It was found that the cascade control improved the stability range in two applications under consideration and made the HVAC feedback control loops more robust and adaptive.

Single zone (SZ) air handling units (AHUs) are widely applied in the conditioned spaces. A SZ AHU typically consists of a chilled water cooling coil, a hot water heating coil, and a supply fan. For a constant volume (CV) SZ AHU or variable air volume (VAV) SZ AHU operating at a minimum airflow, the control valve of either the cooling coil or heating coil is modulated to vary the supply air temperature and consequently control space air temperature. Traditionally, a single control loop is applied to modulate the control valve directly based on the space air temperature. The traditional control is simplistic in nature, however, suffers significant drawbacks. Due to the thermal capacity of both the water in the coils and the air in the conditioned space, the system often becomes unstable due to nonlinear characteristics of the SZ AHU system and leads to hunting of the control valve. On the other hand, cascade control makes the control system more adaptive and robust. A cascade control can be applied to a SZ AHU in order to stabilize the system. The primary controller reads the room air temperature and determines the required supply air temperature for a secondary controller which then controls the heating/cooling coil valve. The purpose of this paper is to demonstrate the stability of the cascade control method in a SZ AHU system. A model of the SZ AHU system with transfer functions is developed for conventional and cascade control methods and root-locus analysis is performed. The results conclude that the cascade control improves the stability of the control valve by reducing the sensitivity to the change in the operating conditions.

Over the coming two decades Asia will be the main driver of a 40% increase in global energy consumption. Ambitions for a more sustainable future in the region are severely compromised by the widespread and rapid take-up of energy-intensive methods for cooling the built environment. For the majority of Asia’s countries buildings account for more than 50% of all national greenhouse gas emissions. With around half that energy consumption typically associated with cooling or heating interior spaces, national carbon footprints have increased dramatically in recent decades through the introduction of electronic airconditioning.
This paper argues such trends are unsustainable and low-carbon alternatives for environmental comfort are required urgently. It traces shifts in how air has been ‘materially imagined’ over the last century or so in Asia and how this bears upon the future of sustainable urbanism. Air-conditioning is seen as pivotal to transformations in urban design and living, such that two phases of modernity are identified: preconditioned and conditioned. By foregrounding the need for low-carbon alternatives, the paper advocates for an alternative, low-carbon regime of thermal governance.

Today, energy crisis turn out to be a serious threat towards sustainability for developing countries since their energy demand is growing more rapidly than developed countries. On the other hand, fossil fuels cannot sustain anymore in the near future because of environmental impacts and depletion of the reserves. Malaysia is experiencing drastic growth in population and economy and requires exploring alternative energy sources to support its population and commercial energy demand. Biomass as the fourth largest energy resource in the world is abundant in the country. Malaysia is blessed with tropical and humid climate all year round which is a magnificent opportunity for fully exploiting agriculture and tropical forests potential. Since late 1990, the concept of waste-to-wealth had been promoted and became popular widely. This concept is based on unwanted wastes which are converted into valuable energy while reducing waste generated and increase the economy-efficiency mainly used for cooking, space heating and power generation. Currently, concerted efforts and various biomass energy programs are supporting by the government for development, demonstration and commercialization. This paper intent to present the current state and prospects of biomass utilization and strategies promoted for future developments in Malaysia.

http://www.sciencedirect.com/science/article/pii/S1364032111001535

In this paper, a purposely designed code for the performance analysis of the Water Loop Heat Pump (WLHP) systems is presented. Hourly, daily and seasonal energy system consumptions, operating economic costs and environmental impact assessments are dealt with. For the scope of comparison, the performances of two reference HVAC system are investigated too. For the computation of the building heating and cooling requirements, a suitable dynamic performance simulation model is being developed.
All the relevant algorithms are implemented in MATLAB�. A case study of an office building undergoing simulation in different European climatic areas is being presented. Here, different building thermal features are considered. In order to maximize the system performance an additional optimization procedure to the operating devices temperatures is carried out. Results show that primary energy savings and avoided CO2 emissions of the WLHP system vary in relation to the compared reference systems and can be obtained only in several European weather zones. The feasibility of the WLHP system strongly depends on electricity and natural gas national costs.

La UNI-EN 15759-1: 2011 richiede il rispetto del clima storico, come imposto dalla UNI-EN 15757: 2010 “Conservazione dei beni culturali - Specifiche concernenti la temperatura e l’umidità relativa per limitare i danni meccanici causati dal clima ai materiali organici igroscopici”  Questo vale anche nel caso dell’installazione di nuovi sistemi di riscaldamento che non possono e non devono stravolgere il clima naturale storico. Questa condizione diventa un limite quasi insuperabile per l’installazione di un sistema di riscaldamento di tipo tradizionale, originariamente concepito e sviluppato per le esigenze domestiche o dei capannoni industriali.

This study represents an experimental and numerical investigation of the enhanced prototypes of the induction air heaters. For this purpose, flow field is enhanced in order to avoid turbulence. The air mass flow rate, outlet construction and the application of insulation of the outer surface of the heater were selected as the performance enhancing parameters. Depending on the exit construction, the new designed prototypes are named as K-2 and K-3. Experiments were performed under two groups for three various flow rates. In the first group, non-insulation situation is examined. In the second group tests, insulation is applied to the outside of windings and inlet-outlet flaps which constitute the boundary of the control volume for the prevention of heat losses. The increasing flow rate boosted the thermal efficiency by 9%. Each of insulation and enlarging exit cross section increased the thermal efficiency by 13%. It was observed that the thermal power transferred to air with the new prototypes increased about 246 W more than the previous designs. The thermal efficiencies of the K-2 and K-3 type heaters were calculated as 77.14% and 87.1%, respectively.

In this paper, a novel purposely designed dynamic simulation model for the performance analysis of solar heating and cooling systems is presented. The investigated system layouts are based on single stage LiBr–H2O absorption chillers and on both evacuated tube and concentrating photovoltaic thermal solar collectors. Furthermore, both electric chiller and gas fired heater backup system are considered. Such model is implemented in a computer code written in MATLAB. Here, the optimisation of several system design and operating parameters in terms of energy saving is also carried out. A code to code analysis is performed comparing the obtained simulation results vs. those achieved by a TRNSYS model available in literature. The simulation code for the concentrating photovoltaic thermal solar collectors is validated by experimental data. A good agreement among results is observed in both the cases. A suitable case study referred to a building including both offices and dwellings located in Northern and Southern Italy is presented. High primary energy savings are obtained for some of the investigated system layouts. By evacuated tube collectors solar field such savings can reach 74%, while shifting to concentrating photovoltaic thermal solar collectors they often surpass 100%. The system economic profitability strongly depends on future scale economies and eventual public funding.

In certain parts of the country and the globe, a consistent and steady supply of power is still scarce and inaccessible. In such places, this work will support refrigeration of nourishments, food, medications, etc... The results of such an empirical research to assess the efficiency of household refrigerators is discussed in this article where melted petroleum gas (LPG) which is locally accessible comprising of 24.4% propane, 56.4% butane, and 17.2% isobutene varying from company to company is utilized as a Refrigerant. The use of LPG for refrigeration purpose can be environment friendly since it has no ozone depletion potential (ODP). LPG is often used to prepare food in homes, restaurants, hotels, and other establishments. CO2 and H2O are the combustion components of LPG. We built and evaluated a refrigerator that uses LPG as a refrigerant in this project. LPG is available in cylinders at high pressure. When this high pressure LPG is passed through the capillary tube of small internal diameter, the pressure of LPG is dropped due to expansion and phase change of LPG occurs in an isenthalpic process. The liquid refrigerant gains latent heat as it transitions from liquid to gas, and the temperature decreases. LPG can create a cooling effect in a confined space in this manner. We discovered that a refrigerator that uses LPG has a higher COP than a domestic refrigerator after conducting experiments.
Keywords: Innovative Refrigerator, LPG Refrigeration, Isobutene, LPG, liquefied petroleum gas, Capillary tube, Evaporator, COP, VCR, Refrigerating Effect.

Adequate and consistent energy supply is often regarded as a major factor in the development of any country. To add to this, the depletion of fossil fuels has also emphasised the need for alternate renewable energy solutions to meet global energy needs without inflicting any serious environmental impacts. Solar energy is globally acknowledged for its vast potential, as a source of providing most of the heating, cooling and electricity needs of the world. One of the most effective uses of solar energy is water heating. The use of solar energy to heat water has been proven to be a very economical, efficient and environmental friendly option for domestic as well as commercial applications. This study compares the feasibility of domestic solar water heater installation in three major cities of Pakistan i.e. Lahore, Karachi and Peshawar. The results show the solar water heater installation is most feasible in Peshawar, among the three selected cities.

Global warming, ozone layer destruction, and limited energy resource enforce us to find alternative refrigeration system can operate with low heat thermal source so that it can be powered by solar energy or lower temperature waste heat. The adsorption system is an alternative way to solve these problems. A fundamental experiment of activated-carbon + methanol was conducted to reveal their application. The experimental apparatus consists of a reactor embedded water jacket. The reactor is filled by the activated carbon. Desorption and sorption processes in the reactor undergo by flowing hot and cool water into the water jacket. An adsorption process takes place when methanol was evaporated from evaporator and then adsorbed by activated carbon in the reactor kept in temperature range of 24°C to 26°C by water cooling. Desorption of methanol is performed by heating of the reactor from 60°C to 100°C. The experiment is to investigate the adsorption behaviour of methanol on the activated-carbon surface. Three sizes of the local activated carbon were considered in the experiment. Dubinin’s equation is used to characterize the adsorption properties. The activated carbon with medium size of 2.5 - 3 mm gives the highest value of the adsorbed methanol adsorption. The activated carbon was improved by using 10% mass additional salts which are sodium carbonate, sodium bicarbonate, and sodium chloride. The activated carbon with additional sodium chloride gives the maximum adsorption quantity and adsorption capacity.

Green façades are becoming an important architectural element in an urban environment. Regarding the technology of the installation of green façades, one can distinguish between direct and indirect green façades, living walls and double skin façades with foliage. In addition to aesthetics of green façades, an impact on the outdoor and the indoor comfort has been proven. That is due to changed temperature and air flow conditions at the building envelope boundary. It has been proven that green façades impact lower surface temperatures of a building envelope and enhance thermal insulation properties of a building envelope, thus reduce energy demand of a building. Based on results from green façade thermal response research and growing interest in local ventilation systems one can conclude that there is potential for a free cooling of a building. Therefore, this paper presents the design and the preliminary experimental research of a local ventilation system coupled with an indirect green façade. Based on the experimental work it has been ascertained that the indirect green façade can impact a 5 K lower inlet air temperature for the local ventilation system compared to the one at the traditional façade.

Improving the sustainability and performance of existing housing stock is a significant challenge. Agencies and organisations have promoted various policies and programmes to address these matters including retrofitting insulation and the installation of energy-efficient heating and cooling technologies. Such initiatives could be enhanced through a more thorough understanding of how such technologies correspond to people’s everyday lives. We argue that the way in which people respond to these and other initiatives are mediated by their personal and familial needs and desires, as well as, broader social, political and economic factors.

Our social scientific study examined the ways people heat and cool their homes and the processes they go through in deciding whether to replace or retain their existing forms of heating and cooling. Twenty qualitative interviews were conducted with residents in their homes in Christchurch and Lower Hutt. Subsequently a quantitative questionnaire survey was developed and delivered to 3500 residential homes in Auckland, Rotorua, Tauranga, Christchurch and Dunedin. This research is part of a multidisciplinary GNS Science project funded by the Foundation for Research, Science and Technology (FRST). The project is aimed at helping to facilitate the development and utilisation of low-temperature (
150ºC) geothermal resources in New Zealand.

Results of the study show typical New Zealand households use electricity and/or a wood burner to heat one or two rooms in the house. The lounge is most commonly heated, although some households (particularly those occupied by young families and elderly residents) heat bedrooms in the interest of maintaining their health and wellbeing. Most households rely on natural ventilation through windows and doors to cool their homes. When selecting new forms of heating or cooling, people typically interpret information in light of its source, and triangulate particular information ‘packages’ with data available from other sources they consider to be relevant. In this context, discussions with family and friends can be equally, if not more, influential than expert consultations and information provided by suppliers, companies, councils and government agencies. In concluding we argue that it is critical to recognise that improving the sustainability and performance of existing houses and buildings is inextricably a social process.