Experimental and feasibility study of the utilization of u-shaped heat pipes for reducing air humidity in HVAC systems

Along with various activities carried out in the building, an HVAC system is needed to provide a comfortable room in terms of temperature and humidity control for its occupants. Operating an HVAC system requires a large amount of energy, which is around 30% of the total energy consumption in the building, so it is important to reduce its energy consumption. To meet room temperature set point in conventional HVAC system, overcooling the fresh air and heating it back to achieve the needed room humidity is inevitable. This research has investigated the effect of utilization of U-shape heat pipe for reducing supply air humidity by reheating process before entering a conditioned room. The U-Shaped heat pipe experiments were varied using one row and two rows with six heat pipe in each row. The inlet air temperature in the evaporator section was varied of 35°C, 40 °C, and 45 °C, while the inlet air velocity varied of 1.5 m/s, 2.0 m/s and 2.5 m/s. The results showed that the two-row of U-shaped heat pipes can reduce the relative humidity as much of 21.31%. The highest effectiveness of 46 % was obtained when using the two-row U-shaped heat pipes at inlet air temperature of 35 °C and air velocity of 1.5 m/s. The highest energy saving in reducing air humidity was 647 W, which was achieved with the two-row U-shaped heat pipes at inlet air temperature of 45 °C and air velocity of 2.5 m/s. With that amount of energy-saving value, the fastest payback time can be achieved by using the two rows U-shaped heat pipe for 0.5 years (six months), respectively.