TitleAuthorParametersResultsConclusionsRemarks

1. Fatty Acids used as Phase Change Materials (PCMs) forThermal Energy Storage in Building Material ApplicationsChuah T. G., Rozanna D., Salmiah A., Thomas Choong S. Y. and Saari M. Melting temperature (C) Heat of fusion (kJ/kg) Thermal conductivity Density (kg/m3)The absorption capacities of PCM in the specimens and compressive strength tests show that the composite was capable of storing up to 30% wt of PCM.

The composite can be produced in the form of floor, wall or ceiling tiles capable of storing energy up to 766 kJ/m2.

Latent heat of fusion has contributed to the overall heat storage capacity in a wallboard impregnated with the esters and their mixtures.

Gypsum:before impregnation, cp = 1.8 kJ/kg C;after impregnation, cp= 2.0 kJ/kg C.b. Brick:before impregnation, cp = 1.6 kJ/kg C;after impregnation, cp = 1.7 kJ/kg C.

Definition of impregnate:to cause (a material) to be filled or soaked with something(Source: http://www.merriam-webster.com/dictionary/impregnate)Fatty acids have good potential thermal characteristic as PCM since they have desired thermodynamic and kinetic criteria for low temperature latent heat storage

However, investment in fatty acids as PCM storage in the building materials may not be economically justified if only energy savings were accounted for. The effect of improved thermal comfort should also be taken into consideration.Thus, more work should be done on enhancing and improving the economic viability of such an investment.Fatty acids advantages melting congruency good chemical stability non-toxicity suitable melting temperature range in liquid phase, surface tension in the order of 2-3 x10-4 N/cm: a value high enough to be retained in the structure of the host material. fatty acid base PCMs are chemically, heat and colour stable, low corrosion activity and nontoxic because of the protected carboxyl group. Derived from the renewable resources common vegetable and animals oil.

calcium hydroxide (Ca(OH)2) in the block, since certain organic PCMs will react with it.

There are possible efficient fatty acids that can be used as PCMs but are costly so it is not to be considered

Compounds that are suitable for our research, due to the melting temperature and heat of fusion are:Capric-lauric acids(45-55%) 21C , 143kJ/kgDimethyl sabacate 21C , 120-135a34% Miristic acid + 66% Capric acid -24C, 147.7aVinyl stearate - 27-29C, 122aCapric acid 32C, 52.7

where the melting temperatures range from 29 degrees celsius to 32 degrees celsius, room temperature in the Philippines

2. The Solidification Behavior of Phase Change Materials for Low-temperature Energy StorageMaria Natalia Roxas Dimaano and Takayuki Watanabe Temperature Solidification time Discharge energy probe height positions mole fractionThe heat transfer shift from convection to conduction proceeds fast.

As solidification develops, the concentration of the C-L acid increases axially upward. The concentration difference is influenced by the conductive mode of heat transfer in C-L acid.As C-L acid solid accumulates at the bottom, the pentadecane is left rich in its liquid form. It is shown in the figure that pentadecane solidifies from the outer region inward at the higher fixed height location while more of C-L acid in the upper layer solidifies first in the inner region. The effect of considering the effective thermal conductivity to account for the natural convection in the heat conduction-based phase change model is validated for the C-L acid mixture on its solidification process The 50 vol% of C-L acid in the C-L acid and pentadecane mixture exhibited obvious heterogeneity that is not suitable for thermal energy storageIt is important for a PCM consisting of two or more components to be homogenous or else it would not be suitable for thermal energy storage.

There were lots of equation provided in this study to measure if the PCM under study is effective. Examples of the equations include Taylor Series Approach, Numerical integration.There were formulas for effective thermal conductivity per unit of cell, temperature, Grashof number, the enthalpy for liquid phase, solid phase and phase transition.

There was not enough notation for the equations though. The authors might have thought that readers already know the formulas. We have to study the notations in order to further understand how to use the equations.

I also found out that the greater temperature difference between the PCM melt and the wall temperature corresponds to a more effective conductive mechanism yielding higher discharge energy in the C-L acid.

3. Cooling vests with phase change material packs: the effects of temperature gradient, mass and covering areaGao, Chuansi; Kuklane, Kalev; Holmr, Ingvar cooling rate temperature gradient mass covering areacooling rate of the PCM vests tested is positively correlated with the temperature gradient between the thermal manikin and the melting temperature of the PCMs. The required temperature gradient is suggested to be greater than 6 degrees Celsius when PCM vests are used in hot climates.With the same temperature gradient, the cooling rate is mainly determined by the covering area.The duration of the cooling effect is dependent on PCM mass and the latent heatThis article could be useful in the field of PCM we are interested in.We should take not that the duration of the cooling effect of any PCM is dependent on its mass and its latent heat.

4.Experimental study on the phase change behavior of phase change material confined in poresZhang, Dong; Tian, Shengli; Xiao, Deyan phase change behavior of organic PCMs and phase change composites pore structure of the porous materials was chemical properties of porous materials and phase change materialsFor capric acid with a functional group of -COOH , remarkable elevation of melting temperature was found when confined in porous materials. But for paraffin with only inactive functional groups, no elevationor depression of the melting temperature was found when confined in the porous materialsThere is a different phase change behaviors found for each kind of PCM in porous materials.

The interaction between functional groups of PCM molecules and alkaline spots on the inner pore surface of the porous materials and the Clapeyron equation were used to explain the different shift of the phase change temperatureof capric acid and paraffin in porous materials.Theres a number of equipment used for characterizing PCMs:

Differentialscanning calorimetry is used to measure phase change behavior of organic PCMs and phase change composites. MercuryIntrusion Porosimetry to characterize the pore structure of the porous materials.X-ray fluorescence spectrometry (XRF) and Fourier transformation infraredspectroscopy (FTIR) were used to characterize the chemical properties of porous materials and phase changematerials

5. Energy Saving in Building with Latent Heat StorageE.S. Mettawee, A.I. Ead hourly cooling load temperature time1.In summer the cooling load peak is at 4 p.m. due to the time that heat takes to be conducted through the walls.

2. PCM melting at 22-24oC is workable for free cooling for 6 months. For the rest 6 months, the peak shaving control can be applied by a night electric cooling unit.

3. Within 2 hours of peak load shifting time, the room can be kept cooled at a comfort temperature by cooling with off-peak energy.

4. Using free cooling of PCM can save 30% of the energy used for air conditioning.

5. Using free cooling of PCM can maintain the temperature within the room between 20 to 26C.

6. The change in the air temperature in storage chamber is proportional to the change in the PCM temperature inside the capsules.

7. The change in the air temperature in the room is proportional to the change of ambient air temperature.PCM system is effective for the peak load shiftingThis is for cooling in buildings. The PCM here offers numerous benefits including saving costs, saving the environment by minimizing consumption of energy.

6. Thermal Energy Storage for More Efficient Domestic AppliancesHalime PAKSOY, Selma YILMAZ, Ozgul GOK, Metin O. YILMAZ, 2Muhsin MAZMA, Hunay EVLIYA Temperature Time percent increase in energy efficiency Melting point (C) Heat of fusion (J/g)Results for a case study of waste heat recovery indishwashers showed that maximum temperature increase in the inlet temperature of the second washing cycle was 13.4oC. melting ranges remained constant and latent heat variations were less than 10%. The maximum temperature increase in the inlet temperature of the second washing cycle was measured as 13.4oC when PCM-A was used as PCM. The corresponding increase in energy efficiency of dishwasher was calculated as 22 %. With melting ranges of 120C to +100C and heats of fusion in the range of 94 J/g and 220 J/g, these PCMs can be considered for refrigerators.Application of PCM to Domestic appliances only offers benefits in terms of energy savings.

7. Energy Efficiency Assumptions and Calculations; Typical Refrigerators vs. Phase Change Materials: Ecofridge, UC Berkeley Temperature Energy vapor compression cycleThe compressor can be run only at night when the ambient air, especially outside, is cooler. Thus, the temperature difference across which the vapor compression cycle can be reduced dramatically, providing significant energy savings

Energy savings is about 40%. (280 kWh/year - 462 kWh/year)/ 462 kWh/year = 39.4 %Vapor compression cycle only needs to run once a day to freeze the phase change material, which will then stay cold for the remainder of the day. Thus, saving a lot of energy.This innovation saves energy and reduces power costs.

It offers good calculation techniques that we can use to measure the efficiency of our desired product

8. Achieving Thermal Inertia in Lightweight ConstructionsResultant Temperature (C)Relative Humidity (%)with the introduction of the Coconut Oil there was a reduction in the interior maximum temperaturethe incorporation ofPCMs (Coconut Oil) in lightweight constructions, can lead to a very good thermal performance of thebuilding. However, it was also proved that the increase of the thermal inertia with the incorporation ofPCMs is not enough if not associated with an optimized design of the envelope. For this situation, itwas observed that the solution with PCM and optimized envelope, showed a thermal performance70% better than a typical lightweight solution, both in terms of energy consumption and temperatureswing.This is a journal about coconut oil as a Phase Change Material. It only proves that coconut oil is an effective PCM.Coconut oil is not only a natural PCM but also its temperature of melting point range is suitable and comfortable for humans.

9. Corrosion of metal and polymer containers for use in PCM cold storageIngrid Martorella, Mohammed M. Faridc, Luisa F. Cabeza Temperature Copper and carbon steel must be avoided when using the PCM tested Aluminium is not recommended with the tested PCM. Stainless steel 316 is recommended when in contact with the tested PCMThere are corresponding corrosion effects of different metals and polymer materials in contact with some PCM used in low temperature applicationsGood reminders on which materials we should not use in encapsulation

10. Experimental Study on Space Cooling with PCM Thermal Storage

Eman Bellah Sayed Mettawee, Eldesouki Ibrahim Eid and Sherif Amin Mohammed Amin Time % efficiency Temperature Heat dischargethe variation of the accumulated discharged thermal energy for total return air compared with mix air (50% fresh air). It is clear that during decreasing the accumulated stored thermal energy is greater than that of using 50% fresh air1. During discharging processes: using total return air leads to the increase of the accumulated stored thermal energy. 2. The time required to complete discharging processes increases as the ambient air temperature decreases. 3. Using total return air increases the discharging time. 4. The system efficiency increases by using total return air. 5. During charging process as the brine, initial temperature increases the accumulated stored thermal energy increases. 6. This system do not work with high efficiency when the ambient temperature reaches to 40oC, but it is works with ambient temperature range 30 to 36 oC There are formulas to use for the monitoring the amount of heat charged and later, discharged.

11. Application of phase change material to Save air conditioning energy in building Yuli S. Indartono, Aryadi Suwono, Ari D. Pasek, Alexander Christantho secondary fluid flow rate inlet/outlet temperature at evaporator, and electricity consumed by compressor temperature humidity time Coefficient of Performance (COP) Heat flowcompressor energy consumption is smaller when TME 30% is added into chilled-water. During phase change, heat transfer coefficient is usually high.

heat transfer improvement of water & TME 30% (mass basis) mixture in evaporator. This increase is caused by higher heat capacity of phase change mixture

Surfactant addition into the mixture reduces friction drag or increases flow rate because of that, heat transfer to the evaporator is increased.PCMs as component of secondary refrigerant (chilled water)

With COP of chiller was calculated by measuring temperatures and flow rate of secondary refrigerant, and electricity consumed by compressor

TME is expensive, VO is good candidate to be used in agricultural country like Indonesia. However, more experiments are needed to ensure suitability of VO usage as PCM in chilled-water system.

PCMs as component of secondary refrigerant (chilled water)

With the Temperature of wall with and without MEPCM was measured for 7-8 hours (day time).Mixture between water and both PCMs shows higher COP compared with that of water. Heat transfer improvement and thermal capacity increasing are responsible for the higher COP.MEPCM integration into wall model shows that the MEPCM contribute to suppress inner side temperature of the wall. This lower temperature may reduce cooling load and then AC energy of building.

Both technologies can mutually contribute to save AC energy of a building.One reason why I chose to stick to this topic was because it can solve environmental problems such as global warming and ozone layer depletion problems.

Heat balance in phase-change fluid can be calculated by following equation:

Where:q is heat transfer of fluid containing phase change materialis mixture flow rate,is specific heat at constant pressure of the mixture, are inlet and outlet fluid temperature, respectively,is flow rate of substance which experiences phase-changed, andis latent heat of the phase-changed material

2nd applicationI learned a new technique in the microencapsulation of a PCM

12. Phase-change material wallboardFor distributed thermal storageIn buildingsA.F. Rudd Temperature Latent heat Percent by weight Immersion timeSmall-scale tests using a differential scanningcalorimeter showed an average latent heat of 22.26 J/g (9.57 Btu/lb) at a PCM loading of 25% by weight. The average melting point was 76.8F (24.9C).

Room-scaletests showed that the PCM wallboard had an averagethermal storage capacity of 10.4 Btu/lb (24.2 J/g).Small-scale result vs. Room-scale result varied by only 8.7% compared to the 9.57 Btu/lb(22.26 J/g) recorded by the DSC.

Small scaledifferential scanning calorimetry can adequatelypredict the performance of PCM wallboard when installedin full-scale applications. Large-scaletesting is expensive thus, it may not be required until a PCM wallboard productis well along in development.

The PCM wallboard had anaverage of 2.1 times more thermal heat storage capacitythan standard wallboard over a 20F (11.1 C) temperaturechange.coconut fatty acid is 320F (160C) at 6 mmpressure. Since the boiling point is high, it would beexpected that the compound would be quite stable attemperatures well above room conditions.

amount of loading was important in order to maximize the useful amount of thermal storage without allowing weeping of excess PCM from the wallboard.A PCM loading of 25 % by weight was chosen sincetests showed that there was slight weeping of the PCM from the wallboard at higher loadings.

The steady-state room air energy balancewasQinf + Qgen + Qac + Qwind+ Qdoor + Qwb = Qair(1)whereQinf = infiltration load,Qgen = internal heat generation,Qac = air-conditioner load,Qw/nd = window conduction,Qdoor = door conduction,Qwb = heat convected to wallboard surfaces, andQair = thermal storage in room air.

The values of the following can be obtained through various equations provided in the journal. (Page 5)

The difference in wallboard storage between cells B and Cwas equated to the energy stored in the PCM:apcmstor = awbstor,c - awbstor, b (10)

whereQpcmstor = thermal storage in phase-change material;Qwbstorc, = wallboard storage, cell C; andQwbstorb, = wallboard storage, cell B.

DSC measured the melting pointand latent heat of selected phase-changem aterials and someprototype PCM wallboard.

In this journal, problems like odor and corrosion developed because of volatile impurities. It may be possible that the volatile impuritiesin the fatty acid could be vaporized before treating thewallboard

Their future work involves two possibilities in improving the PCM wallboard:1) silica gel desiccant with latex paint and vinyl joint compoundto create textured coatings for PCM wallboard.2) yield a two-layer wallboard, making a composite enthalpy storage wallboard. The back layer could be infused with PCM to provide thermal storage and the front layer would incorporate desiccant to increase moisture storage and to reduce flammability

13. Thermal analysis of PCM based building wall for cooling

Dhanusiya.G Rajakumar.S Temperature Time heatFor certain period PCM converts solid state to the liquid state attain at melting point temperature is 44C led to maximum energy savings.

More amount of inside room temperature is get transferred to the outside of the wallboard and atmosphere.

when the distance is increases it seems the wall temperature also increasedMore amount of inside room temperature is get transferred to the outside of the wallboard and atmosphere. Not only can reduce the cost and energy consumption of air condition system, but also is an effective way of improving building energy consumption to environments negative effects.Fatty acids have good potential thermal characteristics PCM since they have desired thermodynamic and kinetic criteria for low temperature latent heat storage

ADVANTAGES OF PCM(1) Freeze without much super cooling. (2) Ability to melt congruently. (3) Self nucleating properties. (4) Compatibility with conventional material of construction. (5) No segregation. (6) Chemically stable. (7) High heat of fusion. (8) Safe and non-reactive. (9) Recyclable.

14.Characterization of the Capric and Lauric Acid Mixture with Additives as Thermal energy Storage Medium for Cooling ApplicationM. N. R. Dimaano and T. Watanabe Melting Point Depression Molality Time Charged EnergyThe presence of more composition of pentadecane in the mixture apparently causes slower discharge of energy as shown by the 50:50 CL:P. However, it ends up having similar values with pure pentadecane.

the discharge performance exhibited by the 90:10 presents a shorter solidification time with slightly improved energy storage abilityThe DSC analysis of the PCM mixtures of C-L acid with some organic chemical additives elucidated the lowering of melting point of the C-L acid. A temperature depression constant of 10.6 Kkg/kmol providedthe C-L acid 's distinctive characteristic.

Furthermore, the storage assessment of the CL:P blends signifies the enhancement of the C-L acid mixture in the composition of 90:10 CL:P combination for cooling thermal energy storage system application.Melting and solidification times play a vital role to ultimately measure the usefulness of the PCM

15. A review of microencapsulation methods of phase change materials (PCMs) as a thermal energy storage (TES) mediumA.Jamekhorshid, S.M.Sadrameli, M.Farid Morphology structure, and thermal propertiesThe results indicated that the most effective method to prepare microcapsules is through the use of prepolymer solutions and the addition of tetraethoxysilane (TEOS)into the prepolymer solution would result in microcapsules with higher latent heat(H151J/g)than those without TEOS (H88.3J/g).Selection of these microencapsulation techniques is highly dependent on the specifications ofmicrocapsules; the required capsule size,materials of the core and shell, thickness of the microcapsule shell, thermal and mechanical properties of the capsule process must be custom-tailored in order to provide a satisfactory outcomeThere are various types of encapsulation for the purpose it will serve. The group should take note of that.

Excellent choices of encapsulation techniques

16.Microencapsulation of PCMs in Textiles: A ReviewAsif Rahman, Michelle E. Dickinson,Mohammed M. Farid Mass Length Temperature volume percentage force displacementmicrocapsulesproduced using the 10 micro-m membrane are smaller than those produced with the 20 micro-m membrane

New process for microencapsulatinga paraffin wax, RT21, with poly(methyl methacrylate)via membrane emulsification and suspensionpolymerization can be used to increase the thermal capacity of buildings.As for nanocompression, it has to be further need investigated: the nanocompression of individual microcapsules and the development ofcorrelation between microcapsule size and the force required for ruptureThis journal offers new techniques for creating microcapsules

17. PCM Application Methods for Residential Building Using Radiant Floor Heating SystemsJisoo Jeon, Jungki Seo, Su-Gwang Jeong, Sumin Kim particle diameter shell thickness thermal capacity conductivity durability Indoor air temperature HeightPCM having a sufficiently high melting point isapplied as an example unlike the PCM having a melting point between 20-30 in typicalbuildingsUse of PCM decreases the building heating and cooling load, thus reducing the building energy consumption and ensuring a comfortable indoor environmentThis article offers effective economic profit based on the difference of electricity charges, therefore it is a good application for refrigeration.

18. Improvement of the thermal properties of Bio-based PCM using exfoliated graphite nanoplateletsSu-GwangJeong,OkyoungChung,SeulgiYu,SughwanKim,SuminKim Transmittance Wave numberThrough SEM analysis, we confirmed that Bio-based PCM incorporated well into the structure of xGnP,Bio-based PCMshavesignificantlyless flammable properties, compared to organic PCMs. BioPCMs are made from underused feed stocks, such as soy beanoils, coconut oils, palm oils,andbeef tallow. Also,Bio-based PCMs can be manufactured such that the melting point can be varied between 22.7 1C and78.33 1C.Characteristics of the Bio-based composite PCM were determined by using SEM, DSC, FTIR, TGA and TCi.

19. Arizona Inventors Develop Phase-Change Heat Reservoir DeviceDer Jeou Chou of Maricopa County, Ariz

Daniel Todd Nelson of Cave Creek, Ariz Heat timeThe excess heat load during transient operation is temporarily absorbed by the latent heat of fusion when the phase change material changes its phase from solid to liquid. Subsequently, the absorbed heat can be released back to the ambient via a heat rejection subsystem.This allows engineers to design smaller heat sinks capable of accommodating given transient conditions. This results in heat sinks which are lower cost and smaller size, or which reduce the requirement to provide higher airflow, thereby also decreasing cost and noise, and increasing reliability.This journal is about the phase-change heat reservoir device for transient thermal management

heat reservoir device for managing a heat input subject to transient conditions includes a heat transfer subsystem having a first end and a second end, where the first end is thermally coupled to the heat input; a heat storage subsystem coupled to the second end of the heat transfer subsystem, where the heat storage subsystem comprises a phase change material responsive to the transient conditions

20. Saturated fatty acid ester phase change materials and processes for preparing the sameMohammed Farid Heat Temperature melting and freezing temperature ranges congruency of melting nucleation characteristics, supercooling and stability to thermal cyclingMore than 300 cycles were done on the ester and the results show no change in its characteristics, indicating that the ester produced is stable. Figure 13 shows the mass loss of gypsum boards impregnated with fatty acid esters produced according to the present invention and the commercially available paraffin RT21 after being kept in an oven at 30C for one month. Figure 14 shows a comparison between the vapour pressure of paraffin and fatty acid esters produced according to the present invention, at different temperatures

Peak heat release rate (PHRR) of the above mentioned ester of the invention in HDPE without fire retardant was 1109 kW/m2 (compared to 1507 kW/m2 for RT 21). The PHRR of esters of the invention in HDPE with fire retardant was 783 kW/m2 (compared to 1107 kW/m2 for RT 21 with the same fire retardant)Fatty acid esters produced according to the present invention is a more fire safe PCM than RT 21 due to a lower PHRR(Peak Heat Release Rate).There are three different types of PCMS for this journal: organic, inorganic and eutectic.

A technique taught here in increasing the latent heat of an organic PCM is through Hydrogenation. Hydrogenating the fatty acid esters converts any unsaturated fatty acids to saturated fatty acids. This in turn significantly increases the latent heat of the fatt)-' acid esters, making them more suitable as PCMs. Hydrogenation also both increases the melting point and narrows the melting point range of the fatty acid esters. A narrow melting point range is a desired characteristic of a PCM.