An Experimental Evaluation on Air Conditioning Performance with Vairtex Air Director Applied on Residential Condenser Unit [thesis]

Ngoc Nguyen
First invented by Gerard Godbout -co-founder of VairTEX Canada Inc., the US and Canadian patented-device called VairTEX Air Director is installed on top the air-cooled condenser top discharge to improve the efficiency of air conditioning/refrigeration systems. Through tests at their industrial partners in Canada and in the United States, the device has demonstrated its effectiveness by reducing compressor power consumption, where a highest saving of 21% was recorded. However, as VairTEX has
more » ... en to focus on the industrial/commercial markets, no data has been obtained for residential air conditioning system to further validate the company claims. An experimental study was carried out to evaluate the effectiveness of VairTEX Air Director device on a modified 1.5-ton air conditioner located in the thermodynamic laboratory at the Department of Mechanical and Aerospace Engineering -Carleton University. The experiment was divided into two parts. The first part included thermodynamic performance evaluations at two different refrigerant flow rates. In particular, coefficient of performance (COP), power consumption, refrigeration capacity were examined in order to provide comparisons of these parameters with and without the Air Director device implemented. As the Air Director was installed on the condenser unit, COP was improved by an appreciable ii amount of 4% and 5% on mean values while compressor power consumption was reduced by 3.7% and 4.5% with respect to mean values at two refrigerant flow rates, respectively. The second part involved three directional velocity measurements to characterize air flow discharge from the condenser with and without the device, which then could help to clarify why such improvement existed on condenser performance in particular and for an air conditioning system as whole. A measuring method developed by King and modified by Janjua called -'Six-orientation hot-wire probe technique', was explored to determine three velocity components using single-normal hot-wire probe. A compact experimental setup was also designed and constructed to perform calibration for velocity range in this study. In addition, a temperature correction method from Hultmark was validated and employed to make the experiment possible in non-isothermal flow field. By modifying profiles of three velocity components, the Air Director has straightened exit flow where the radial component was significantly reduced while axial flow was greatly improved. As a consequence, an increase of 48.7% in volume flow rate was achieved. Tangential component at the Air Director exit resembled the profile found in cyclone devices. Temperatures collected at the Air Director exit demonstrated an increase in heat dissipation from the condenser unit compared to bare condenser case and hence, increased the heat transfer between the ambient and refrigerant. Thus, condenser performance was improved. iii Abbreviations AC Air conditioning AD Air director AS Aspect ratio CFC Chlorofluorocarbon CFM Cubic feet per minute COP Coefficient of performance CR Contraction area ratio xx CTA Constant temperature anemometry EER Energy efficiency ratio GPM Gallon per minute HFC Hydrofluorocarbon HVAC Heating,ventilation, and air conditioning HWA Hot-wire anemometer LPM Litre per minute NRCAN Natural Resources Canada PIV Particle image velocimetry RECS Residential energy consumption survey RMS Root mean square RPM Rotation per minute SEER Seasonal energy efficiency ratio SOM Six-orientation method TC Thermocouple xxi
doi:10.22215/etd/2018-12706 fatcat:ak4jzbhurreapjaec4u44kmgue