Prototype Room Research Articles

Application of Soy Wax Phase Change Material as Thermal Energy Storage in Wall Building

High solar radiation in the tropics area buildings and inappropriate selection of building materials cause an increase in room temperature which interferes with thermal comfort. This study aims to reduce the absorption of heat received in the building with the modification of building walls by adding Phase Change Material (PCM) as Thermal Energy Storage (TES). Soy wax is an organic PCM that is abundant in Indonesia, cheap, and has a melting point of 43.92°C and a freezing point of 38.49°C, which are the range of solar heat radiation in buildings. The application of soy wax on the walls of the building is carried out using a prototype room 80x105x60 cm made of Plywood with a 1 cm thickness of soy wax in the middle of the wall. The test was carried out by comparing the prototype without and with a layer of soy wax pack on the wall. Based on the tests carried out for 24 hours, it was found that the addition of soy wax on the prototype wall can decrease the room temperature to 37°C from 41°C during the day. The use of soy wax can absorb the heat received by the building by 10% at peak load and has a small heat transfer rate of 15.56 W so the heat transferred into the room is small. Soy wax walls function as insulators on the walls and can withstand heat absorbed from outside the building so that it is not completely transferred into the room.

A study of the Effect of Air Inlet and Exit on Indoor Air Movement

This work consists of a numerical simulation to predict the velocity and temperature distributions, and an experimental work to visualize the air flow in a room model. The numerical work is based on non-isothermal, incompressible, three dimensional, k turbulence model, and solved using a computational fluid dynamic (CFD) approach, involving finite volume technique to solve continuity, momentum and energy equations, that governs the room’s turbulent flow domain. The experimental study was performed using (1/5) scaled room model of the actual dimensions of the room to simulate room air flow and visualize the flow pattern using smoke generated from burnt herbs and collected in a smoke generator to delivered through the prototype room. The numerical results were compared with those obtained from experiments, the correspondence between numerical and experimental was fairly good and also, a fair comparison was found with other workers in this field.

Tricklevent Yenilikçi Pasif Cephe Havalandırma Sisteminin Isıl Konfor ve Enerji Tasarrufu Açısından İncelenmesi

In our study, the effects of the Tricklevent passive ventilation system with the international patent application number 2013/08326 on thermal comfort and energy saving were examined. Tricklevent innovative passive ventilation system is a ventilation system placed on the facade and controlled by an automation system designed vertically or horizontally. In our study, a 14 m2 prototype room with Tricklevent system was built and measurements were taken from places determined by thermocouples as the system was closed-open. The tests were conducted at 11:00 am during the hottest hours of the day on August 15-16, 2021. The system was also analyzed with computational fluid mechanics software. For numerical analysis, the Re number was calculated and it was determined that the flow was turbulent. The k-Ɛ turbulence model was used in the analyses. In the analysis, independence from the network was studied. The Discrete Transfer model was used as the radiation model. 1009 W/m2 solar load is defined. The velocity of the ambient air is calculated as 1.94 m/s, the pressure difference is 2.19 Pa and the air flow to be taken from the system is calculated as 0.024 m3/s. According to the results obtained in the tests, it has been determined that when the Tricklevent system is turned off, the indoor temperature exceeds the ambient temperature within 16 minutes with the effect of radiation, and the indoor temperature reaches a maximum of 30 °C in 16 minutes and 34.5 °C after 24 minutes when the system is on. It has been determined that a temperature drop of 2-3 oC is sufficient when Tricklevent Y.P.H.S is on, while the air conditioner should provide a temperature drop of approximately 6.5-7.5 oC when the system is off. It has been observed that the compressor operating time will be longer when the system is off. As a result of the study, it was seen that 14 kWh energy saving was achieved in the prototype room. According to the power of the air conditioner, as a result of not operating the air conditioner for 16 minutes, 16% savings were achieved in a 1-hour period. Depending on the height of the building, the operating time of the air conditioner can be up to 34 minutes with the advantage provided in air flow and temperature. This showed that the energy savings to be made can be between 16-50% in 1 hour time.

Passive Cooling System to Provide Thermal Comfort

Abstract: In a country like India, where temperatures may reach 40 degrees Celsius, everyone wants relief from the sweltering heat, but only a few can afford it. As a result, passive cooling is a low or no energy approach that relies on heat gain management and heat dispersion to offer thermal comfort. Heat Protection, Heat Modulation, and Heat Dissipation are the three basic types of passive cooling systems. The combined effect of approaches from each category on a prototype room is examined in this research, which includes shading and green roofs for heat protection, thermal mass (PCM) for heat modulation, and cross ventilation for heat dissipation. Thermal mass is a term that describes a substance's ability to store heat. The three primary phases of a Thermal Energy Storage (TES) system are thermal charging, thermal storage, and thermal discharging. Phase Change Materials or PCM are latent heat storage materials. The roof is one of the most exposed parts of a house to the sun, accounting for over half of the heat gain in a single-story home. As a result, heat protection might be a viable option for lowering heat gain via the roof. A green roof, or a roof with vegetation, is one such system that operates on the principle of evapotranspiration, which is the combined action of soil evaporation and plant transpiration. Another effective method of heat shielding that is used in everyday life is shading. Shading is a basic technique for blocking sunlight before it enters a structure by using structural components such as overhangs, light shelves, horizontal louvres, or blind systems. Cross ventilation is a natural cooling method that uses wind to force cold air into a structure through an opening while driving warm air out. Natural ventilation of this sort is low-cost and ensures that a structure is suitably cooled. There are many such different passive cooling techniques used in different regions of the world in the form of individual as well as hybrid system. This project focuses mainly on Hybrid Systems. Thus, the objective of this project is to integrate PCM and other secondary passive cooling techniques for creating a hybrid passive cooling system to provide thermal comfort.

Study on the heat gain through a twin glass window (TGW) using an organic PCM

The glazed windowing systems are the essential components for a wide range of structures, and their heat transfer performance does have a substantial impact on increasing an human comfort as well as lowering electricity usage. The current study analyzes the heat transfer characteristics of a twin glass window (TGW) unit, under the influence of a commercially procured organic phase changing medium (PCM). The results have been compared the performance of the normal TGW without the presence of PCM and the inferences are discussed. The two TGW units had been erected in an prototype room space facing south direction in a South Indian region. Through a lengthy experimental investigation, the room space temperatures, glazing surface temperatures, transmittance of the glazing surface and the heat exchange rate across the TGW unit of both the normal TGW unit as well as PCM amalgamated TGW units were assessed. The testing findings demonstrated that amalgamating PCM is being a potential solution reduce the indoor temperature having TGW unit, without sacrifice of entering sun light inside the room space. By this way, it would help to reduce the cooling load of the air-conditioning system, which results in the reduction of total eenrgy consumption of the building space.

Design of a Home Fire Detection System Using Arduino and SMS Gateway

Fire is a problem that can happen at any time. Delay in coping with house fires can induce in loss of human life or material. If the fire is not held severely, incidents like house fires can occur and create more significant losses, especially with the increasing number of residents’ settlements in the formation of huddled houses, which will be more challenging to handle in case of a fire. This research aims to build a prototype system that quickly helps house owners and firefighters to detect fires and gas leaks. This home fire detection system is utilized to measure room temperature and gas levels in a room, then the output of this system is sending information of short messages and alarms. The results revealed that the prototype room with a scale of 1:25, 1:50, and 1:75 which uses a temperature sensor and a gas sensor could run as desired. In 10 testing trials, the system works according to the designed plan, which means the system could interpret the temperature and gas leakage of a room, then the system will send a short message and ring the alarm.

A Novel Green Alternative for a Room Prototype Constructed with Entire Recycled PET Bottles and a Green Roof Composed of Waste Materials

In this study, we propose a methodology for constructing a prototype room intended primarily for people with low incomes, allowing self-construction practices and upcycling of widely available waste materials in their original form. Mechanical tests were conducted on single bottles of poly(ethylene terephthalate) (PET) filled with different materials as well as on entire PET bottle/concrete blocks. Higher strength was observed when the bottles were in a horizontal position. The mechanical performance of the construction solution adopted for the prototype was not tested, and therefore its structural adequacy was not proven. The insulating multilayer roof was composed of waste plastic bags, two layers of uncapped PET bottles of differing shapes and sizes, another layer of plastic bags, waste cardboard, soil from the site, and a top endemic plant green layer. The PET bottles used in construction were filled with clay from the site, although bottles filled with fly ash achieved better mechanical results. The bottles can also be used uncapped and empty, which would simplify the process considerably by reducing the filling stage. This can be considered to be the main proposal for this type of building. There were almost negligible solid wastes generated, since they were used in the multilayered green roof. From a top view, the prototype mimics the surroundings because the green roof incorporates soil from the site and endemic plants.

Designing a Patient Room as a Fall Protection Strategy: The Perspectives of Healthcare Design Experts.

Despite decades of research into patient falls, there is a dearth of evidence about how the design of patient rooms influences falls. Our multi-year study aims to better understand how patient room design can increase stability during ambulation, serving as a fall protection strategy for frail and/or elderly patients. The aim of this portion of the study was to ascertain the architect’s perspective on designing a room to mitigate the risk of falls, as well as to evaluate the face validity of a predictive algorithm to assess risk in room design using the input of a design advisory council (AC). The purpose of this paper is to provide insight into the design process and decision-making for patient rooms; summarize the impressions of industry experts about the configurations and layout of the patient rooms tested in a preliminary augmented reality model; establish the face validity of modeled heat maps depicting risk; and report the results of a pre-meeting and post-meeting survey of expert opinions. Feedback was coded using human factors/ergonomic (HF/E) design principles, and the findings will be used to guide further development of an “optimal” prototype room for human subject testing. The results confirm the challenges that architects face as they balance competing priorities and reveal how a participatory process focusing on preventing falls can shift assumptions about design strategies, especially subtle changes (e.g., toilet orientation).

A newly composed paraffin encapsulated prototype roof structure for efficient thermal management in hot climate

For efficient thermal management in the building under hot weather condition a new paraffin composition as suitable PCM is needed. Several notable attributes of paraffin wax including thermo-physical properties, open air atmospheric condition, economy, and environmental amiability make them suitable PCM for incorporation in the building. Thus, new PCM with massive storage of heat or cold in a specific volume is demanded. Iraqi local paraffin waxes as PCM are proven to be highly prospective due to their high-vitality thickness and isothermal conduct. However, thermal performance optimization of new PCM is pre-requisite to determine its effectiveness in hot climate location. We prepare three new PCM compositions with different oil to wax ratios from the crude petrochemical feed stock waste using fractionation followed by de-waxing and crystallization. The melting temperatures and flash points of these paraffin waxes are ranged between 19 and 44 °C and 177–256 °C, respectively, which upon encapsulation in the prototype roof construction are demonstrated to produce thermal comfort in rooms under hot climate (Iraq). Furthermore, these indigenous PCMs (local paraffin) are abundant, environmental friendly, economic and save electricity cost and HVAC (heating-ventilating air conditioning) systems. Experimental results displayed much reduced temperature fluctuation and internal heat flux of the prototype room than the commercial PCMs. Temperature profiles and solar irradiances inside the room on hot summer days in Bagdad showed remarkable electricity saving. This newly extracted PCM being non-flammable and thermally comfortable are truly secure for buildings construction worldwide.

Effect of radiator position and mass flux on the dryer room heat transfer rate

A room radiator as usually used in cold countries, is actually able to be used as a heat source to dry goods, especially in the rainy season where the sun seldom shines due to much rain and cloud. Experiments to investigate effects of radiator position and mass flux on heat transfer rate were performed. This study is to determine the best position of the radiator and the optimum mass flux. The radiator used was a finned radiator made of copper pipes and aluminum fins with an overall dimension of 220mm×50mm×310mm. The prototype room was constructed using plywood and wood frame with an overall size of 1000mm×1000mm×1000mm. The working fluid was heated water flowing inside the radiator and air circulating naturally inside the prototype room. The nominal mass fluxes employed were 800, 900 and 1000kg/m2s. The water was kept at 80°C at the radiator entrance, while the initial air temperature inside the prototype room was 30°C. Three positions of the radiator were examined. The results show that the effect of the mass flux on the forced and free convection heat transfer rate is insignificant but the radiator position strongly affects the heat transfer rate for both forced and free convection.

다수의 출구를 가진 선박용 대형 저소음 룸유닛 개발

In this paper, the acoustic performance of a shipboard large-sized room unit is studied. The room unit is a kind of rectangular absorptive chamber with a partition whose surface absorptive material with fabric skin is attached to. The room unit has one inlet and three outlets. At the inlet, a plane damper is installed to control the flow rate. The acoustic performance of a prototype room unit is measured using a HVAC mock-up. It is shown that its insertion loss is comparable with that of a commercially-used room unit but the developed room unit generates flow noise higher than the other one. The major source of flow noise is analyzed by NADS-R, the noise analysis program for room unit. Cone-shaped dampers are proposed to be used as the damper of a room unit to reduce flow noise. It is shown that the cone-shaped damper decrease flow noise remarkably.

Multiple Position Room Response Equalization in Frequency Domain

This paper deals with methods for multiple position room response equalization. Differently from a well-known technique working in the time domain and based on fuzzy c-means clustering, in the proposed approach most of the operations are performed in the frequency domain and, in particular, the fuzzy c-means clustering is applied to the room magnitude responses at different positions. It is shown that working in the frequency domain allows us to obtain equalization performances at least similar to those of the time domain approach with a strongly reduced computational complexity. In addition, different techniques that can replace the fuzzy c-means clustering algorithm in the derivation of the prototype room response equalizer, with additional reduction of the number of operations, are discussed. Finally, the results of three sets of experiments are used to illustrate the performance, the robustness and the quality of the proposed room response equalization method using alternative prototype design strategies applied to different environments.

Accumulation and transport of microbial-size particles in a pressure protected model burn unit: CFD simulations and experimental evidence.

BackgroundControlling airborne contamination is of major importance in burn units because of the high susceptibility of burned patients to infections and the unique environmental conditions that can accentuate the infection risk. In particular the required elevated temperatures in the patient room can create thermal convection flows which can transport airborne contaminates throughout the unit. In order to estimate this risk and optimize the design of an intensive care room intended to host severely burned patients, we have relied on a computational fluid dynamic methodology (CFD).MethodsThe study was carried out in 4 steps: i) patient room design, ii) CFD simulations of patient room design to model air flows throughout the patient room, adjacent anterooms and the corridor, iii) construction of a prototype room and subsequent experimental studies to characterize its performance iv) qualitative comparison of the tendencies between CFD prediction and experimental results. The Electricité De France (EDF) open-source software Code_Saturne® (http://www.code-saturne.org) was used and CFD simulations were conducted with an hexahedral mesh containing about 300 000 computational cells. The computational domain included the treatment room and two anterooms including equipment, staff and patient. Experiments with inert aerosol particles followed by time-resolved particle counting were conducted in the prototype room for comparison with the CFD observations.ResultsWe found that thermal convection can create contaminated zones near the ceiling of the room, which can subsequently lead to contaminate transfer in adjacent rooms. Experimental confirmation of these phenomena agreed well with CFD predictions and showed that particles greater than one micron (i.e. bacterial or fungal spore sizes) can be influenced by these thermally induced flows. When the temperature difference between rooms was 7°C, a significant contamination transfer was observed to enter into the positive pressure room when the access door was opened, while 2°C had little effect. Based on these findings the constructed burn unit was outfitted with supplemental air exhaust ducts over the doors to compensate for the thermal convective flows.ConclusionsCFD simulations proved to be a particularly useful tool for the design and optimization of a burn unit treatment room. Our results, which have been confirmed qualitatively by experimental investigation, stressed that airborne transfer of microbial size particles via thermal convection flows are able to bypass the protective overpressure in the patient room, which can represent a potential risk of cross contamination between rooms in protected environments.

Dynamics structure of a room-temperature ionic liquid bmimCl

We have measured the neutron scattering from 1-butyl-3-methylimidazolium chloride (bmimCl), which is known as a prototype room temperature ionic liquid. The temperature scan of the elastic neutron scattering showed that glassy bmimCl has a fast β relaxation appearing above T g as observed in many of molecular and polymer glasses. The quasielastic neutron scattering data of liquid bmimCl showed that the motion of bmim + ions is regarded as a simple diffusion. The activation energy calculated from the temperature dependence of the self-diffusion coefficients is smaller than that of the intramolecular rotation of butyl-group. This result indicates that bmim + ion is very flexible and stabilizing the ionic liquids entropically.

06/00947 Carbon supported Pt 70Co 30 electrocatalyst prepared by the formic acid method for the oxygen reduction reaction in polymer electrolyte fuel cells : Salgado, J. R. C. et al. Journal of Power Sources, 2005, 141, (1), 13–18.

The use of phase change materials (PCMs) for thermal storage in buildings was one of the first applications studied, together with typical storage tanks. An interesting possibility in building application is the impregnation of PCMs into porous construction materials, such as plasterboard or concrete, to increase thermal mass. The thermal improvements in a building due to the inclusion of PCMs depend on the climate, design and orientation of the construction, but also to the amount and type of PCM. Therefore, these projects require a complete simulation of the thermal behaviour of the designed space in the conditions of use established a priori.In this paper a simple methodology for the energetic simulation of buildings including elements with PCMs using the program TRNSYS is presented and validated. This procedure does not aim a simulation of the real transfer processes inside the materials with PCM, but to evaluate the influence of walls/ceiling/floor with PCM in the whole energy balance of a building. The key parameter in the simulations is the equivalent heat transfer coefficient which has to be determined for each material. Experimental evaluation of the coefficient is presented. The methodology is applied in a building such as a prototype room built with concrete panels with PCM.

Experimental Study on the Thermal Performance of the Shape-Stabilized Phase Change Material Floor Used in Passive Solar Buildings

The novel shape-stabilized phase change material (PCM) has the following salient features: large apparent specific heat for the phase change temperature region, suitable thermal conductivity, and the ability to keep the shape stabilized when it undergoes a phase change. In this technical brief, we put forward a kind of shape-stabilized PCM floor that is able to absorb solar radiation energy in the daytime and to release the heat at night in winter. The thermal performance of a prototype room using such a floor was studied. The experiments show that the mean indoor temperature of a room with the PCM floor is about 2°C higher than that of the room without a PCM floor, and the indoor temperature swing range is obviously minimized. Therefore, installing shape-stabilized PCM in a room may increase the degree of thermal comfort and reduce space heating energy consumption in winter. In addition, the experimental results provide data for modeling and simulation research for such PCM floor systems.

An approach to the simulation of PCMs in building applications using TRNSYS

The use of phase change materials (PCMs) for thermal storage in buildings was one of the first applications studied, together with typical storage tanks. An interesting possibility in building application is the impregnation of PCMs into porous construction materials, such as plasterboard or concrete, to increase thermal mass. The thermal improvements in a building due to the inclusion of PCMs depend on the climate, design and orientation of the construction, but also to the amount and type of PCM. Therefore, these projects require a complete simulation of the thermal behaviour of the designed space in the conditions of use established a priori. In this paper a simple methodology for the energetic simulation of buildings including elements with PCMs using the program TRNSYS is presented and validated. This procedure does not aim a simulation of the real transfer processes inside the materials with PCM, but to evaluate the influence of walls/ceiling/floor with PCM in the whole energy balance of a building. The key parameter in the simulations is the equivalent heat transfer coefficient which has to be determined for each material. Experimental evaluation of the coefficient is presented. The methodology is applied in a building such as a prototype room built with concrete panels with PCM.

Experimental study of under-floor electric heating system with shape-stabilized PCM plates

This paper put forward a new kind of under-floor electric heating system with shape-stabilized phase change material (PCM) plates. Different from conventional PCM, shape-stabilized PCM can keep the shape unchanged during phase change process. Therefore, the PCM leakage danger can be avoided. This system can charge heat by using cheap nighttime electricity and discharge the heat stored at daytime. In the present work, the thermal physical properties of shape-stabilized PCM developed by us were measured. A prototype room with this system was set up in Beijing to testify its thermal performance and feasibility of this heating mode. The results show that temperature of the PCM plates upper surface can be kept near the phase transition temperature in whole day and a lot of off-peak period electricity can be used for space heating in stead of using peak period electricity, which obviously lowers the electricity tariff.

Room temperature La0.7Sr0.3MnO3 magnetoresistive prototype memory element

Highly (110) textured La0.7Sr0.3MnO3 polycrystalline film strips in conjunction with a small interacting bias magnet have been used to construct a prototype room temperature memory element. The film strips were made by high laser pulse energy pulsed laser deposition such that the temperature of the resistance maximum was elevated to room temperature. Consequently room temperature operation did not require any temperature compensation. The magnetoresistance of such film strips exhibited highly anisotropic low field magnetoresistance with the largest response for applied fields in plane and parallel to the current direction. Perpendicular to the plane applied fields produced no response in the low field region. A simple bridge was configured in which the sensing element was a 100-μm-wide manganite strip made to exhibit a broad resistance maximum at room temperature. The memory element magnetoresistive response for field excursions approaching the intrinsic coercivity of the bias magnet exhibited two distinct zero applied field resistance values. Parallel versus antiparallel field excursions to 60 mT produced zero applied magnetic field voltage states separated by 18 mV at room temperature in a geometry investigated.

Acoustical evaluation of halls for the performing arts using acoustical models

A series of relatively new objective measures of the acoustical quality of performing arts halls such as temporal energy ratios, early decay times, and rise times has been investigated and compared to each other and the perceived quality of the halls by many researchers. Measurements of these criteria were made at multiple positions in 1:10, 1:40, and 1:100 scale models of a 1500‐seat multipurpose performance hall and in equivalent positions in the prototype room. There were clearly distinguishable zones of differing acoustical response shown in reflectograms made in the prototype room and even the smallest models. The objective measurements taken in the small size models with wideband noise duplicated the measurements taken in the larger size models and the prototype room reasonably well. The measurements made on an octave‐band basis in the 1:10 scale model and the prototype room at equivalent positions show acceptable correlation. Twenty thousand hertz was the midband frequency for the highest octave band in the models that yielded acceptable values without correcting for air absorption. The ease of testing and the comparative results make this a valuable tool for preliminary testing of design alternatives.