Energy efficiency study for a small commercial outlet and associated factory offices in Gozo

Abstract

In this study, an energy audit, an indoor environment quality test and a survey on indoor comfort were carried out for a small commercial outlet and associated factory offices in Gozo, in order to measure the level of energy efficiency, indoor comfort and air quality, as well as survey the feedback from workers and employees on indoor comfort. From an energy consumption point of view, air-conditioning and lighting consumed most energy for both the offices and the shop, totalling 69% and 41%, respectively. In the lee months, when air-conditioning is least used, electricity consumption of computers top the list amounting to 63% in the offices. Other appliances in the office such as photocopiers, kettles/coffee machines, water dispenser and the fridge are the least consuming with a total of 3% share of energy consumption. In the shop, air-conditioning and baking ovens are the most energy consuming among the appliances. Several office rooms were found to have a temperature that exceeded the comfort level and two offices had high levels of carbon dioxide concentration. Final conclusions for potential energy savings in the office, included wall insulation, the replacement of the deteriorating air-conditioning systems and associated piping systems and the continuation of the upgrading exercise of the remaining non-efficient lighting bulbs. Also, extractor fans with carbon dioxide sensors should be installed in the two identified offices to improve indoor air quality. For the retail outlet, the installation of a double door or an air curtain at the entrance door and a stairs door to separate the lower baking floor from the shop are urgently needed, to stop the loss of airconditioned air from the shop. Furthermore, lighting circuits into different zones, while the replacement of glass with double glazing partitions for the display cooking areas of the shop would reduce cooling loads.