The Application of U-shape Heat Pipe Heat Exchanger to Reduce Relative Humidity for Energy Conservation in Heating, Ventilation, and Air Conditioning (HVAC) Systems

Abstract

Hospitals consume large amounts of energy, especially in their heating, ventilation, and air conditioning (HVAC) systems due to the special requirements for ensuring healthy, comfortable, and safe environmental conditions. The use of a Heat Pipe Heat Exchanger (HPHE) is recommended as a means of minimizing electricity consumption with no loss of comfort while also improving indoor air quality. An experimental study was conducted to investigate the performance of a U-shape HPHE in recovering exhaust air heat from an indoor room included in an HVAC system. The U-shape HPHE consists of several tubular U-shape heat pipes with water as a working fluid and arranged in a staggered configuration. Tests were carried out to determine the impact of the inlet air temperature, air velocity, and the number of heat pipes on its effectiveness. The experiment revealed that the higher the temperature of the inlet air, the more effective the U-shape HPHE. The results show that the temperature of the air entering the cooling coil decreased by 1.73 °C with an effectiveness value of 7.64 %. This result was achieved using 12 U-shape HPHEs, which had a staggered arrangement, an air velocity of 1.5 m / s, and an air temperature entering the evaporator of 45 °C. The highest amount of heat recovery, 2190.43 kJ/hour, was achieved when the air velocity was 2.5 m/s.

The Review of the Application of the Heat Pipe on Enhancing Performance of the Air-Conditioning System in Buildings

“…The highest effectiveness of the two-row HPHE reached 12.4% under the conditions of the minimum inlet air speed of 1.5 m/s and inlet air temperature of 35 • C rather than the maximum temperature of 45 • C, which was inconsistent with the conclusion in Ref. [110]. Kusumah et al [110] applied a U-shaped HPHE to enhance the dehumidification performance of the ACS.…”

“…The peak values of the COP and EER of the proposed ACS were increased by 14.9 and 17.6%, respectively. Kusumah et al [110] applied a U-shaped HPHE to enhance the dehumidification performance of the ACS. The HPHE consisting of THPs was vertically placed in AHU (shown in Figure 33a).…”

“…Water was encapsulated into the HPHE, which served as the working fluid. The thermal effectiveness and the heat recovery of the HPHE were Kusumah et al [110] applied a U-shaped HPHE to enhance the dehumidification performance of the ACS. The HPHE consisting of THPs was vertically placed in AHU (shown in Figure 33a).…”

“…[110]. Kusumah et al [110] applied a U-shaped HPHE to enhance the dehumidification performance of the ACS. The HPHE consisting of THPs was vertically placed in AHU (shown in Figure 33a).…”

Energy conservation of HVAC systems in isolation rooms using heat pipe heat exchangers

“…U-shaped heat pipes reduce the inlet temperature at the cooling coil by 1.73 °C with an effectiveness value of 7.64%. The highest heat recovery of 2190.43 kJ/h is obtained at an air velocity of 2.5 m/s, and the relative humidity is reduced by 12.2% [ 11 ].…”