The research used an energy audit technique, which enables us to better understand how energy is utilized in a building and identifies potential energy wasting areas as well as areas for improvement. The various process are as follows:

1. Preparation/ Pre-audit phase: This involves collecting data on the hostel facility, including its physical characteristics, energy consumption history, and any existing energy management systems or programs.

2. Physical Inspection: it involves a walk-through audit of the hostel facilities, observing the students' behaviors and consumption patterns to obtain a clear understanding of the energy consumption pattern.

3. Data Collection: Data was collected by physically counting lighting and electrical items, as well as determining the average usage time, number of rooms, and number of students in each room. Structured questionnaires were administered to a sample of students to obtain information regarding their awareness of energy conservation, energy consumption patterns, and energy-saving practices. The hostel population was divided into two main strata: male and female. The questionnaires were administered using a combination of simple random sampling and stratified sampling techniques. A total of 80 rooms were included in the study, which accounted for more than 45% of the entire hostel population.

4. Data Analysis: Microsoft excel was used to analysed the data. Based on the end-use, the connected loads were classified into different categories (e.g., lighting, refrigeration, cooling, cooking, heating, and others) and estimate the electricity usage using load reducing factors such as diversity factor and duty cycle.

Table 1.

Cost of Energy = Energy (kWh)* 0.08728235 USD/kWh … …. (1)

The data presented in Figure 1 and Figure 2 of the study indicate that a substantial proportion of the electricity consumed in the hostel is credited to the male and female hostel blocks. These two blocks constitute the majority of the residents in the hostel, and collectively they account for 93% of the total electricity used in the building. The remaining 7% of electricity consumption is attributed to the management offices and the commercial activities within the hostel building, which accounts for 3% and 4% respectively. Further analysis of the data reveals that out of the 93% of electricity consumed by the two blocks, the male block contributes about 56%, while the female block accounts for 37% of the total electricity usage. This information indicates that addressing energy efficiency and conservation measures within the male and female blocks would be a significant step towards reducing overall electricity consumption in the hostel.

The study analysed the energy consumption of the student hostel and found that there were significant differences in electricity usage among different categories of loads. Results from Figure 3 and Figure 4 show that cooking is the biggest energy consumer, accounting for 50% of the total electricity consumed by the hostel on a monthly basis. This finding confirms that the male and female blocks, who are the only contributors to cooking, are the major consumers of energy in the hostel. Lighting is also a major contributor to electricity consumption, representing about 16% of the total energy used. Refrigeration, heating, cooling, and other categories of loads also contribute to electricity consumption, with refrigeration accounting for 10%, heating for 8%, cooling for 5%, and others contributing about 11% of the consumed electricity in a month.

The various categories, their consumption and contributions to the electricity bills are further discussed in details below.

The audit team observed that the hostel management has installed mostly Compact Fluorescent Lamps (CFLs) and fluorescent bulbs, which are energy-efficient types of bulbs. However, during the walk-through audit and based on the responses from the administered questionnaires, the audit team observed that external light bulbs were often left switched on during the day. Additionally, it was noted that students frequently left the light bulbs in their rooms illuminated even when they were away attending lectures. The questionnaire results revealed that 69% of the respondents agreed that light bulbs were occasionally left on during the day, a finding that was corroborated by the audit team's daily visits.

By turning off the lights in rooms when not in use and turning on external light bulbs only at night, the average daily 'ON' hours of light bulbs can be reduced to 9.5 hours from 14 hours, which results in a 32% reduction in energy spent on lighting is equivalent to 3,331.56kWh or $290.79 in cost savings. This reduction in energy consumption will lead to a decrease in electricity bills for the hostel. Additionally, to make the lighting system of the hostel more efficient, the hostel management can consider replacing the CFLs and fluorescent bulbs with LED bulbs. LED bulbs are highly efficient, have a longer lifespan, emit little heat, do not contain toxic materials like mercury dust found in fluorescent bulbs, and are more versatile. This could result in even greater energy savings and cost reductions for the hostel over the long term.

When considering power consumption, energy efficiency, energy costs, and average lifespan, replacing current CFL bulbs with LEDs will cut lighting electricity consumption in half, resulting in close to 50% monthly savings. The 18W CFLs will be replaced by 8W LEDs, and the 36W fluorescent will be replaced by 26W LEDs, which are slightly more expensive than CFLs. LED bulbs cost between $1.2 and $1.5.

The cooking category in the hostel consists of rice cookers, electrical hot plates, and blenders, and it is identified as the activity that consumes the highest amount of electricity. According to Figure 4, it contributes to around 50% of the total electricity usage in the hostel. Figure 6 provides a breakdown of the contributions of each cooking appliance to the overall electricity consumption in cooking activities alone. The results depicted in Figure 6 reveal that electrical hot plates alone consume approximately 69% of the electricity utilized for cooking, resulting in a monthly consumption of 22,113 kWh and a corresponding cost of $1930.07. Figure 5

The hot plates used in the hostel exhibit the highest percentage of energy consumption compared to other appliances. Specifically, rice cookers contribute to 29% of the energy used for cooking, while blenders only account for 2%. During a walk-through inspection of the hostel, it was observed that many students utilize inefficient hot plates instead of efficient ones. These inefficient hot plates have high-power ratings and lack proper regulation, operating with a duty cycle of one, meaning they continue to draw current even when the heating element is already red-hot. As a result, a significant amount of electrical energy is wasted, and there is a risk of damage to cables and socket outlets. By transitioning to efficient hot plates with lower power ratings and improved duty cycles, energy consumption could be significantly reduced. Efficient hot plates are equipped with regulators for temperature and duty cycle control. If the regulated hot plates were the primary ones used in the hostel, the high efficiency they offer could lead to energy savings of over 50%. Currently, the majority of hot plates in use are inefficient, with power ratings exceeding 2,000W, representing approximately 90% of all hot plates in the hostel.

Possible savings from the use of efficient electrical hot plates:

Average Power ratings of inefficient hot plates: 2,250W = 2.25KW

Average power ratings of efficient (regulated) hot plates: 1000W = 1KW

Replacing the inefficient hot plates with the efficient regulated hot plates implies a 1250W or 1.25kW savings per each used hot plate.

As such, (1.25/2.25) * 100 = 55.56% energy savings from the hot plates.

Amount of energy used by hot plates monthly = 22,113KWh

55.56% of 22,113kWh = 12,285.98kWh

That is $1072.35 savings monthly.

As shown in Figure 4, this accounts for 10% of the monthly electricity consumption. The hostel has a total of 116 refrigerators, with 61 in the male rooms (as indicated in Table 1andTable 2), 47 in the female rooms (as indicated in Table 3), 3 in the management offices, and 5 in other areas (as indicated in Table 4 and Table 5, respectively). Options for saving energy primarily depend on the habits and behaviours of the users. Therefore, residents' behaviour towards the use of such appliances should be a priority, ensuring that they have some basic knowledge concerning the use of such things. Some of these include:

1. Location: During our visits, we noticed that residents placed their refrigerators near areas where they engage in cooking. These are typically warm places that increase the compressor work and, therefore, increase energy consumption. They should be informed to place them in well-ventilated areas to enhance air flow and improve efficiency. Table 6

2. To save energy, it is important to develop good habits such as tightly closing refrigerator doors after use. This helps maintain the desired temperature and prevents energy loss. Additionally, switching off the refrigerator when it is empty can contribute to further energy savings. Table 7

3. Unnecessary opening of the refrigerator also increases energy consumption. Table 8

As shown in Figure 4, this category accounts for 8% of the electricity consumed in the hostel monthly. The heating category consists of irons, heating kettles, hair dryers, and microwaves. Most appliances in this category operate for a short period of time, and with their high input power ratings, they do not work for a long time, hence they do not consume lots of energy over the operating time. Ironing, which is part of this category, was a major contributor to the consumption of the category. Each room has at least two irons, and in most rooms, only one is used by all four members in the room.

To save energy from ironing, residents should practice ironing in bulk. This means they can always iron as many clothes as they will be using over the week and do it together instead of doing it individually on a daily basis. This reduces the consumption of ironing as they always surge to heat up initially anytime, they are plugged in, drawing huge amounts of power in the process of starting up. So, if they were to practice bulk ironing, they would not be using much power for surge, and most of the irons also have good duty cycles, hence they will operate for longer periods without consuming throughout the whole time of operation. However, from our daily visits, we realized that students mostly iron when they are about to leave for lectures, so they put the iron 'on' for what they want to wear at that moment. Doing this individually increases consumption.

The category comprising air conditioning and fans accounts for 5% of the monthly electricity consumption in the hostel, as shown in Figure 4. Only a few areas in the building have air conditioning units installed and operational, most of which have high ratings with good duty cycles, making them relatively efficient. However, the temperature settings are frequently adjusted, causing the air conditioners to work harder to cooperate with the new settings. Consequently, they record very low duty cycles, which reduces their efficiency and leads to an increase in consumption. To operate efficiently, the temperatures should be kept relatively stable and not set too high from the ambient temperature, which helps the air conditioners work within a certain range over a more extended period. This ensures good duty cycles, which will increase efficiency and reduce consumption.

Fans, which are also part of this category, make up a significant part of the cooling consumption due to their numbers. During our audits, we observed that some residents leave their fans on for extended periods, even when they are not present. They justify their actions by saying that they want to cool the room before returning. However, it should be noted that the longer the fan operates, the more heat energy it produces. This heat will then have to be battled by the same fan, reducing its efficiency and increasing consumption. Therefore, residents should turn off their fans when leaving their rooms. Additionally, natural ventilation should also be used to support the cooling of the rooms, as the hostel is located in a forest zone with tall trees. The rooms have spacious windows and an open balcony to support natural ventilation, which will reduce the operation hours of the cooling equipment and hence reduce consumption.

This category encompasses all other appliances not included in the previous categories, such as computers (laptops and desktops), phones, photocopiers, printers, televisions, and others. As shown in Figure 4, this category accounts for 11% of the monthly energy consumption in the building. The high consumption in this category is largely due to misconceptions about the operation of some appliances and the poor behavioural habits of the residents when using them.

During the audit, it became evident that most residents do not unplug their laptops and phones from the chargers or remove the chargers from the sockets when the batteries are fully charged. This means that these appliances continue to draw current from the source unnecessarily, using more energy than needed and increasing consumption. Many residents mistakenly believe that leaving the chargers plugged in has no effect when the batteries are fully charged, but this is not the case.

To save energy, desktops, printers, and photocopiers should be put on energy saver or standby modes when not in use, or turned off if they will not be used for extended periods. This will reduce energy consumption and minimize wastage.

Savings from reducing operational (ON) time of lighting = 32% = 3,331.56kWh and amount to $290.79 per month.

Savings from lighting with retrofitting = 45.11%, making 4,627.747kWh, which is equivalent to $403.92 savings per month.

Savings from lighting by retrofitting and reducing “ON” time = 62.22% which is equivalent to 6,478.429kWh and amount to $565.45

Savings from cooking = 55.56% = 12,285.9828kWh, that is $1072.35 savings monthly

Total savings (reducing “ON” time + cooking) = 15,617.543KWh = $1363.14

Total savings (with retrofits + cooking) = 16,913.7298kWh = $1476.27

Total savings (reducing “ON” time + cooking + retrofitting) = 18,764.4118kWh = $1637.80

In comparison to the monthly electricity bill of $5,667.20, the total savings amount to a significant 29% reduction in the hostel's monthly electrical energy costs.

The Table 9 below shows a summary of potential recommendation measures and estimated monthly and energy savings from our audit hotspots (lighting and cooking).