Dehumidification Amount Research Articles

Dehumidification load ratio: influence mechanism on air conditioning and energy saving potential analysis for building cooling

The construction energy consumption (EC) makes up around 35% of the total energy used. Half of this energy is used for air-conditioning to cool spaces. The effectiveness of cooling relates to various factors, particularly the dynamic thermal performance of air-conditioners (AC) in different conditions. Studying heat pumps in diverse hot and humid climates, especially where dehumidification matters in summer AC, reveals efficiency. Examining the connection between coefficient of performance (COP) and heat removal aids in lowering building energy usage and improving cooling systems. To achieve this, a validated thermodynamic model of heat pumps and a specific transient building heat transfer model were combined. The study focused on three distinct hot and humid climate zones: Guangzhou, Wuhan, and Jiuquan. Simulations of heat pump performance were conducted throughout the year to analyze variations in COP, relative humidity (RH), and latent heat load (LHL).Key findings indicate that the COP of heat pumps is notably influenced by the practical amount of dehumidification required. A positive correlation (correlation coefficient: 0.52151) exists between COP and LHL, emphasizing the importance of addressing dehumidification needs. The research highlights that the COP remains consistently high when the heat pump manages between 45% to 80% of the LHL. Practically, these findings have crucial implications for heat pump applications and building EC reduction, particularly in regions with pronounced dehumidification requirements during the cooling season. By understanding the interplay between heat pump efficiency, humidity, and heat load, practitioners can optimize heat pump performance to achieve energy savings. This research provides a valuable reference for designing and implementing cooling systems in various hot and humid climates, facilitating energy-efficient practices and environmentally friendly building operations.

Numerical investigation and comparison on energy performance and exergy destruction of cascading deep dehumidification systems with dehumidification amount exceeding 95%

Liquid desiccant and desiccant wheel systems are feasible approaches for the dehumidification process in modern buildings. Some specialized buildings and industrial fields have the demand for deep dehumidification process to produce supply air with low dew point temperature below 0 °C. In this study, the numerical investigation has been conducted to evaluate the energy and exergy performance of multiple cascading deep dehumidification systems assisted with liquid desiccant and desiccant wheel under a great dehumidification gradient. To process the air from 21 g/kg to 1 g/kg, the results indicate that the cascading liquid desiccant and desiccant wheel deep dehumidification system (LD-DW system) driven by two stages of heat pump exhibits the lowest demand of power consumption compared with the conventional dehumidification systems. It also shows less exergy loss and significantly higher exergy efficiency than other systems. The effects of influencing parameters on the dehumidification performance are also evaluated. The LD-DW system can effectively match the air state with the proper treatment dehumidification process, thus achieving a superior coefficient of system performance (COPsys) of 3.70, and it is an energy and exergy efficient method for advancing the deep dehumidification process.

Multi-objective optimization of air dehumidification membrane module based on response surface method and genetic algorithm

The pressure driven membrane-based air dehumidification technology is a promising energy-efficient technology for the air conditioning systems. To promote the engineering application of membrane dehumidification technology, factor significance analysis and multi-objective optimization of dehumidification membrane module were numerically investigated. Response surface method (RSM) was adopted to design the desired simulation cases and analyze the significance of five key factors, i.e., feed velocity, water vapor permeability coefficient, filling rate, fiber length, fiber diameter, on the membrane dehumidification characteristics. The second-order regression models of the dimensionless dehumidification amount per unit area (ma*) and the dehumidification rate (γ) were established based on the analysis of variance (ANOVA). It was found that the water vapor permeability coefficient has the most significant effect on γ and ma*. However, the dehumidification coefficient of performance (COP) and the frictional coefficient (f*Re) are hardly affected by the five independent factors. An average COP of 2.523 implies a good dehumidification efficiency of membrane module. As a multi-objective optimization method, the genetic algorithm was used for the membrane module optimization. The optimal solution represented by Pareto frontier is finally obtained in terms of γ and ma*. The optimized factor-level combination can be selected from the Pareto solution set according to the actual requirements of energy consumption and dehumidification efficiency.

Dehumidification behavior of an aluminophosphate zeolite coated crossflow heat exchanger driven with direct hot water heating and evaporative cooling

• Crossflow heat exchanger coated with AlPO zeolite for desiccant dehumidification. • Demonstration of an adsorber combining a heater, cooler, and heat exchanger. • Direct supply of hot water to the adsorber for heating and regeneration. • Effective indirect evaporative cooling performed by internally remaining hot water. • Profiling of the adsorption/desorption outlet air condition for cycle optimization. In this study, a crossflow-type heat exchanger coated with aluminophosphate zeolite was tested for desiccant dehumidification with direct-supplied hot water and evaporative cooling using remaining hot water. This evaporative cooling process could accelerate dehumidification by removing the heat of adsorption. Therefore, the influences of the cooling air velocity, regeneration hot water temperature, and adsorption/regeneration cycle time were experimentally investigated. The result showed that the minimum humidity of the adsorption outlet air decreased with an increase in the cooling air velocity and adsorption/desorption time, indicating that the complete regeneration of coated adsorbents is required to significantly decrease humidity. However, the maximum time-averaged amount of dehumidification appeared at an appropriate cycle time, which avoided adsorption saturation during the adsorption period. Further, in any case, increasing the cooling air velocity had a positive impact on both the momentary observed minimum humidity and time-averaged amount of dehumidification. At all cooling air velocity, the temperature of the hot water contributed to the increase in the time-averaged amount of dehumidification. However, when the hot water temperature was 55 °C, the cooling effect of evaporative was not observed, even when the cooling air velocity reached 1.5 m/s. Considering that the actual temperature of the coated adsorbent was expected to be much lower than that of the supplied hot water, the hot water temperature should have been ≥ 65 °C.

A case study of a pilot system with gas-engine heat pumps and a desiccant air handling system using higher chilled water temperature in Japan

• The exhaust hot water from gas-engine heat pumps can be effectively used. • Water at 12 °C from gas-engine heat pumps achieved a 20% higher performance. • Higher chilled water temperature had no influence on the indoor environment. • Coefficient of system was 0.76 when chilled water temperature was raised. A desiccant air handling unit (DAHU) is a major dehumidification system in which adsorbents adsorb moist air. The system requires hot water to regenerate these adsorbents. In this study, a gas-engine heat pump (GHP) with a simultaneous supply of chilled and recovered hot water from the engine was installed as a heat source for a DAHU. Because a DAHU does not require low-temperature chilled water for condensation dehumidification, the impacts of higher-temperature chilled water on a DAHU and the whole system were investigated. Preliminary to the measurement, the influence of the rise of the chilled water temperature on air state after pre-cooling coil and after-cooling coil was investigated. According to this preliminary reviews, the raise of the chilled water temperature does not affect on the air state, which means there is no influence of the dehumidification amount at desiccant wheel. Furthermore, the upper limit of the chilled water temperature is at 13˚C. Field measurements with two chilled water temperatures (7 °C and 12 °C) were conducted in summer 2019. The results from these two cases showed that the rise in the chilled water temperature of the GHP improves the coefficient of performance (COP) of the GHP from 0.8 to 1.0, without any influence on the air state in the DAHU or the indoor thermal environment (temperature and relative humidity). Overall, the distribution ratio of chilled and hot water from the GHP was very small compared to that of the whole system, where the system COP was almost the same, at approximately 0.73 between the two cases. However, there is a possibility to achieve 4% of better energy performance of the system by the increase of the chilled water temperature set point from 8 °C to 12 °C.

Evaluation of membrane-based air pre-dehumidification for a capillary radiant air conditioning system

The polyvinylidene fluoride hollow fibre membrane air dehumidification tests were carried out between the liquid desiccant solutions and the wet air. Three liquid desiccant solutions of LiBr solution (50%), LiCl solution (35%) and CaCl2 solution (40%) were tested under different wet air conditions. The results showed that all the membrane dehumidification processes were stable. The air moisture content in the outlet of the membrane was maintained as 6.5 g/kg (da)–8.2 g/kg (da) when the air moisture content in the inlet of the membrane was operated from 17.1 g/kg (da) to 32.4 g/kg (da). The dehumidification amount of LiBr solution (50%) and LiCl solution (35%) was more productive. On this basis, a membrane-based air pre-dehumidification process for the capillary radiant air conditioning system was built. Since the ideal dew point temperature range of the indoor air is below 14–17°C according to the cold supply water, all the air moisture content at the membrane outlet is much lower than that of the ideal dew point temperature range, which means non-condensing occurs in the capillary tube surface. The membrane-based air pre-dehumidification process can easily form an adaptive regulation process of humidity with the capillary radiant air conditioning system under different environmental parameters.

Numerical and Experimental Analysis of a Drying Chamber of a Heat Pump Sludge Drying System

This study proposed an improved design for the typical sludge drying system cooperating with three air-source heat pumps. Performance improvement of the system was conducted by consideration of the internal configuration of the drying chamber and the heat and mass transfer effect of the air in the cabin. Since the heat pump drying system in this study adopts the design of continuous sludge feed, the efficiency of heat and mass transfer between the sludge on the conveyor belt and thet air streams from the condenser in the drying chamber becomes very important. Simulation analysis of the computational fluid dynamics (CFD) software was used to understand the flow field and temperature field distributions in the drying chamber with air deflectors in order to find the appropriate internal configuration design in the drying chamber and system operating parameters. The SMER value (ratio of dehumidification amount and energy consumption) were measured to verify the system improvement effect. The purposed system can enhance the dehumidification SMER value by 32.44%. The simulation temperature differences and the actual measured results are less than 10%, the water content percentage of the discharged dry sludge decrease by 30% after redesign the cabin.

Durability analysis and degradation mechanism for an electrolytic air dehumidifier based on PEM

Electrolytic air dehumidification (vapor electrolysers) based on proton-exchange membrane (PEM) is competitive to conventional dehumidifiers, but serious degradation has been found in long-running applications. This study conducted the durability test of electrolytic dehumidifier, under continuous operation for more than 250 h. Changes in current and dehumidification rate were analyzed and compared to those for fuel cells and water electrolysers. Physicochemical and electrochemical changes of the materials before and after the test were investigated. Results show that higher applied potential or higher air humidity corresponds to a larger dehumidification amount, while performance attenuates more quickly over time. When the applied potential increased from 2 V to 4 V, the degradation rate increases from 23% to 67% at 90% air humidity. Simultaneously, the internal resistance of PEM element increased from 0.419 to 1.45 Ω and the reaction resistance changed from 1.13 to 2.17 Ω, indicating by in-situ and ex-situ EIS. By characterization analysis, it indicated that the corrosion of the anode-side catalyst IrO2 is the main reason for the long-term attenuation. The grain size of almost all IrO2 faces reduced after 250 h dehumidification, and the content of active metal of the catalyst lost by 54.3%. The dissolution rate of IrO2 also increases with increasing applied potential. Besides, there is almost no physical or chemical damage on PEM or cathode catalyst before and after the durability test. This research clarifies the micro-scale changes of the materials during long-term operation, and discloses the degradation mechanism of PEM-based electrolytic dehumidifiers.

Simulation and experimental studies on the liquid desiccant dehumidification of horizontal tubes having a staggered arrangement

Field synergy theory has been widely used in the field of single-phase heat transfer, which is of importance to heat transfer optimization. However, few scholars apply the field synergy theory to the field of mass transfer, especially to the field of liquid desiccant dehumidification. The innovation of this paper is the application of the technology of the falling-film evaporation of a horizontal tube and the theory of field synergy to liquid desiccant dehumidification. The objective of this paper is to study the falling film liquid dehumidifier and get the dehumidification performance and mass transfer synergy angle under the influence of multiple factors. The heat and mass transfer characteristics of the system are studied in simulation and experimentally. The mass transfer synergy angle comprising the velocity vector and concentration gradient vector is taken as a standard to measure the mass transfer synergy, while the moisture content of the outlet air is taken as a standard to measure the dehumidification performance of the system. Fluent simulation software is used to simulate the dehumidification process of the equipment with staggered horizontal pipes, establish physical and mathematical models and analyze the velocity field and moisture content field in the model. The moisture content of the outlet air and the distribution of the mass transfer angle are obtained. The mass transfer angle of the system is about 96°. The effects of various factors on the air moisture content at the outlet of the equipment are studied experimentally. Results show that the dehumidification amount decreases with an increase in air velocity. Increases in the solution concentration, air inlet moisture content and solution flow rate increase the amount of dehumidification, following the same trends as in simulation. A comparison of the simulation results with the experimental results shows the relative error is within 20%. This study shows that it is feasible to combine the field synergy theory with liquid desiccant dehumidification. On the basis of this study, researchers in related fields can further study the effect of mass transfer synergy angle on mass transfer synergy in liquid desiccant dehumidification system.

냉각식 제습기 제습성능 향상을 위한 히터파이프 적용에 관한 연구

This study investigated the application of heat pipe to improve the energy efficiency of the cooling dehumidifier. Dehumidification amount, power consumption, air temperature and dew point temperature were analyzed according to heat pipe application. In the case of using heat pipe, the decrease of the dew point temperature of the dehumidifier was increased by 0.2 ~ 1 ℃ and the dehumidification performance was improved by about 15.0 ~ 31.8% due to the cooling of the inlet air of the dehumidifier. Therefore, it is considered that applying the heat pipe to the cooling dehumidifier improves the performance.

Comparison of Behaviour and Energy Performance of Desiccant Air Handling Unit under Various Control Method

Desiccant air handling unit (DAHU) dehumidifies moisture in the air with adsorbent or sorbent. Hot water is necessary to regenerate them. In many buildings, for regeneration of the dehumidifier, hot water from combined heat and power (CHP) is used because it can supply hot water at stable temperature. When using fluctuating energy such as hot water from solar thermal collector, it is mixed with hot water from CHP in order to compensate the fluctuation, and supplied. In order to use renewable energy including solar thermal energy efficiently, we propose flexible control compared to ordinary fixed control. The ordinary fixed control controls outlet air temperature of pre-cooling coil at fixed temperature, for example 19°C, and the relative humidity is 100%. Therefore, dehumidification amount at dehumidification wheel as well as regeneration coil demand does not fluctuate very much. On the other hand, flexible control controls outlet condition of pre-cooling coil with absolute humidity of supply air and hot water temperature to regenerating coil. When hot water temperature is enough hot, absolute humidity of supply air fulfills set point, therefore pre-cooling coil demand decreases. When hot water temperature is not hot enough, supply absolute humidity does not fulfill the set point. In this case, outlet temperature of pre-cooling coil will get lower in accordance with hot water temperature. This study investigates the behavior and performance of DAHU under different control methods through energy simulation. Simulation results show that when installing flexible control, outlet air state of pre-cooling coil is determined depending on the hot water temperature to regenerating coil. It proves that it is possible to handle required latent heat load even when hot water temperature is low around 45°C. DAHU with flexible control can contribute the effective use of solar thermal heat.]

Experimental and numerical analysis for predicting the dehumidification performance of a hollow fiber type membrane using the log mean pressure difference method

The membrane-based dehumidification method is economical and environmentally friendly. Furthermore, the hollow fiber type membrane (HFM) has superior dehumidification performance because it has a large contact area. Despite many advantages, the membranebased dehumidification method is still in the research and development stage, its use in the field is limited, and research on technology to integrate systems is insufficient. In this study, the relationships between parameters affecting dehumidification performance in terms of dehumidification rate and dehumidification amount were compared in order to apply the membrane-based dehumidification system in the field. The experimental and simulation values were compared in order to find a correlation with the dehumidification amount (or water fraction). Dehumidification performance increased when dry-bulb temperature, relative humidity, and log mean temperature difference (LMPD) were increased. The results of this study can be used to predict system performance in advance when a membrane-based dehumidification system is applied in the field.

Heat and mass transfer in an adjacent internally-cooled membrane-based liquid desiccant dehumidifier (AIMLDD)

An adjacent internally-cooled membrane-based liquid desiccant dehumidifier (AIMLDD) is proposed and used for air dehumidification. The AIMLDD is a parallel-plate membrane contactor, which contains cooling channels. The air and the solution streams are separated by selectively permeable membranes, while the solution and the water streams are separated by plastic plate. The air stream flows in a cross-flow arrangement with the solution stream, while the solution stream flows in a co-current flow arrangement with the water stream. Establish a mathematical model in a unit cell, which contains half of an air channel, a piece of membrane, a solution channel, a piece of plastic plate, and half of a cooling channel, to research the conjugate heat and mass transports in the AIMLDD. Use a finite difference method to solve the normalized equations governing momentum, heat and mass transports. The dehumidification amount, the efficiency and outlet parameters are then obtained. A continuous air dehumidification system based on the AIMLDD is set up to validate the numerical results. Compare the efficiency under different condition and different structure of the membrane contactor. It can be found that the dehumidification amount and the efficiency for the AIMLDD are higher than those for an adiabatic one.

An Experimental Study on Heat Transfer Characteristics of Pilot Wave Heat Exchanger for White Smoke Reduction

In this study, the heat transfer characteristics of pilot wave heat exchanger for white smoke reduction system was investigated. The performance of the wave and honeycomb heat exchanger combined with the first stage, second stage and third stage was tested using a calorimeter. Air and water inlet/outlet temperature and flow rate, pressure drop and dehumidification amount were measured to compare the heat transfer performance according to the type and the combination of heat exchanger. The heat transfer rate and dehumidification amount of the wave heat exchanger were higher than that of the honeycomb heat exchanger, and the pressure drop was low. As the stage increased, the heat transfer rate and the increase of the dehumidification amount were more pronounced, and the pressure drop linearly increased. The wave heat exchanger had a lower flow resistance than the honeycomb heat exchanger with the honeycomb structure and had a higher heat transfer effect due to the convection, so the water outlet temperature was higher in the wave heat exchanger.

Silica gel polymer composite desiccants for air conditioning systems

In this study, we developed a composite material to be used in air conditioning systems by combining silica gel with both polyacrylic acid and sodium polyacrylate. A test was performed to determine the optimal mixing ratio. The results showed that the optimal composite material was produced at a mixing ratio of 10:1:1. Under a closed environment of 25°C and a relative humidity of 70%, the material exhibited a sorption capacity 41% higher than silica gel on its own. Subsequently, tests were performed to assess the dehumidification performance of the material at varying air velocities, regeneration temperatures, and inlet temperatures and humidity. After 15min of usage under conditions of an inlet air temperature of 30°C, a relative humidity of 70%, and a regeneration temperature of 40°C, the performance of the composite material maintained 80% of its highest dehumidification performance. In addition, the average dehumidification amount reached 2.73g/min, which was higher than silica gel packed bed at 2.46g/min. Moreover, the airflow design of the composite material facilitated a pressure drop of 149mmAq/m, which was 0.69 times lower than the silica gel packed bed system. Given the above results, application of the silica gel/polymer composite desiccant to air conditioning systems has great energy-saving potential.

가정용 소형 제습로터의 성능에 대한 실험적 연구

In Korea, summer is hot and humid, and air-conditioners consume too much electricity due to large amount of latent heat. Simultaneous usage of dehumidifier may reduce the latent heat and save the electricity. In this study, dehumidification performance was measured in a constant temperature and humidity chamber for a small-sized dehumdification rotor made of inorganic fiber impregnated with metallic silicate. Variables were rotor speed, room temperature, regeneration temperature, room relative humidity and frontal velocity to the rotor. Results showed that there existed optimum rotor speed (1.0 rpm), and optimum regeneration temperature (100 o C). Above the optimum rotor speed, incomplete regeneration is responsible for reduced dehumidification. Above the optimum regeneration temperature, increased temperature difference between regeneration and dehumidification process is responsible for reduced dehumidification. The amount of dehumidification also increases with the increase of relative humidity, dehumidification temperature and flow velocity into the rotor.

제습기능을 구비한 열펌프의 성능개선에 관한 연구

Abstract This research developed a hybrid heat pump system with the functions of dehumidification and heating, which uses simulated air that is like underground air, from an environmental chamber as a heat source. The system consisted ofthree evaporators and three condensers that were installed in series in the air passage, between the underground and load space. As results, the total amount of dehumidification was 2.726 kg/h, and the heating COP h was 1.84 at air intake temperature17 ℃ and relative humidity 70%, which is a similar condition to underground air. We found that the total amount of dehumidification also increased with the air temperature and humidity. The system COP s was reached at 2.5, if we include the latent heat of dehumidification in the conventional heat pump system’s COP. Key words Geothermal(지열), Heat pump(열펌프), Dehumidification(제습), Series evaporator(직렬증발기)†Corresponding author, E-mail: ycpark@jejunu.ac.kr 기호설명  : 난방성능계수  : 시스템성능계수 : 제습량 [kg/h]  : 물의 증발잠열 [kJ/kg] : 건조공기 풍량 [m

직렬 제습방식 열펌프 시스템의 성능특성에 관한 연구

Abstract: In this research, results of measuring temperature and relative humidity of underground-air-heat in Jeju showed 15~18℃ and 70~80% each which are somewhat high compare to other regions. So the Multi-ef-fect dehumidifying and heating Heat Pump system which has merged functions of dehumidification and heat-ing is made to solve this problem mentioned previously. When the suction air was 15℃ with 60% humidity, the outcome was 1.70 on COP h and 1.797(kg/h) on total amount of dehumidification, and also showed 1.87 COP h with 1.87 total amount of dehumidification under the condition of 20℃ and 80% humidity of suction air. Furthermore, COP h showed increased number which is 1.87 and also total amount of dehumidification in-creased which was 3.269(kg/h). The highest COP can be achieved at 17℃ and 70% relative humidity condition. Keywords: Geothermal, Heat pump, Dehumidification, Heat exchanger, Condenser, Evaporator  기 호 설 명 COP h : 난방성능계수 [-]Q in : 방출열량 [kcal/kg]Q out : 흡입열량 [kcal/kg]W : 공급일량 [W] : 제습량 [kg/h] : 건조공기 비중 [kg/m

Preparation of thick mesoporous silica coating by electrophoretic deposition with binder addition and its water vapor adsorption–desorption properties

Ordered mesoporous silica (MPS) is expected to provide an adsorbent for energy-efficient air-conditioning systems, such as desiccant cooling systems, humidity control systems, and adsorption heat pumps, which can contribute to the reduction of CO2 emissions because they offer the possibility of recovery at temperatures as low as 50°C. For these applications, it is crucial to establish a method for fixing MPS on substrates with high thermal conductivity. We have already studied the technological feasibility of using the electrophoretic deposition (EPD) process to prepare a thick coating of MPS powder on a metal substrate. In this study, we investigated EPD with the addition of a small amount of binder and succeeded in increasing the mechanical strength and thermal stability of the thick MPS coating. The approximately 100μm-thick MPS coating showed excellent water vapor adsorption–desorption properties and sufficient stability for more than 250 adsorption–desorption cycles, without any reduction in the adsorption amount. The dehumidification amount per cycle was 0.23g-H2O/g-MPS, which correspond to 6.9g-H2O/g-MPS/h.

히트펌프 건조기용 PF 열교환기 성능 및 해석 연구

본 연구에서는 히트펌프 건조기용에 적용될 PF 열교환기에 대하여 연구되었다. PF 열교환기의 설치 경사각(<TEX>$0^{\circ}$</TEX>, <TEX>$30^{\circ}$</TEX>, <TEX>$60^{\circ}$</TEX>)에 따른 3종 PF 열교환기의 능력과 제습량을 측정하였다. 실험은 건구온도 <TEX>$60^{\circ}C$</TEX>, 상대습도 70%, 풍속 0.5m/s에서 진행되었다. 실험결과 경사각이 증가할수록 열교환기의 성능이 우수하였으며, PF3가 능력과 제습량에서 가장 우수하였다. 그러나 경사각이 <TEX>$60^{\circ}$</TEX>에서는 능력과 제습량이 크게 감소하였다. 실험값을 예측하기 위해 PF 열교환기의 능력과 제습량을 예측할 수 있는 계산프로그램을 개발하였다. PF 열교환기 3종에 대한 실험값과 계산값은 능력의 경우에 최대 2% 이내를 제습량의 경우에 최대 3% 이내에서 만족한 결과를 보여주었다. In the present study, the performance of a PF heat exchanger for heat pump dryer was investigated. Capacity and dehumidification amount of the PF heat exchangers(PF1, PF2, PF3) by different inclination angles(<TEX>$0^{\circ}$</TEX>, <TEX>$30^{\circ}$</TEX>, <TEX>$60^{\circ}$</TEX>) were studied. Experimental conditions were an air velocity crossing to the heat exchanger(0.5m/s), an air dry-bulb temperature(<TEX>$60^{\circ}C$</TEX>) and relative humidity(70%). The experimental results have shown that the performance of the inclined PF heat exchangers was better than that of the vertically installed one. PF3 showed better performance compared to PF1 and PF2 due to the large pin pitch which are leading to more draining for dehumidified water. But, capacity and dehumidification amount of the PF heat exchanger at the inclination angles of <TEX>$60^{\circ}$</TEX> was decreased due to pressure drop. Also, to predict the experimental data of the PF heat exchanger, the performance program was developed for the inclination angles of <TEX>$0^{\circ}$</TEX>. PF heat exchanger performance between experiment data and calculation data was satisfied within the maximum 2% for capacity and 3% for dehumidification amount.