Waqas Khalid, Adeel Waqas,Waqas Ahmad
Mahar and Faraz Khalid
Building sector of Pakistan consumes 25% of the primary energy and a major portion of this energy is used up by heating ventilation and cooling (HVAC) system. It is also noticed that majority of the buildings are not designed according to local climatic conditions which caused more use of energy for HVAC systems. Therefore, it is recommended to maintain the indoor thermal comfort at an acceptable level while designing the buildings and HVAC systems which is hardly practiced by the building sector in Pakistan.
Thermal comfort is a state in which satisfaction is expressed with the thermal environment. Simply thermal comfort is the comfortable condition when the occupant is feeling neither too hot nor too cold rather satisfied. Thermal comfort varies from person to person and depends on many factors that can be different for the occupants sharing the same space.
The factors upon which the thermal comfort depend are air temperature, velocity, humidity and the radiant temperature of the space occupied by the occupants. Along with these, some personal factors like clothing and metabolic rate also affect thermal comfort. It is estimated that acceptable comfort conditions can be achieved if 80% of the occupants are feeling comfortable sharing the same environment. By creating the comfort conditions in the space, we may not only save the energy but also increase productivity as feeling comfortable directly affects the occupant mood. In buildings, optimal comfort conditions enable the occupants to think and work better, and thermal comfort contributes to positive productivity.
Pakistan is having a wide range of climates including hot humid, hot dry, composite, temperate and cold. In 2017-18, the electricity consumption of domestic and commercial sectors was 50% and 26% of total electricity consumption, respectively. Annual energy consumption in the building sector of Pakistan is nearly 25% of its total energy use and it’s increasing with an annual growth rate of 2.9% and 4.1% in domestic and commercial sectors, respectively. About half of the total energy consumed in buildings is in the HVAC system and lighting appliances.
National Energy Policy 2006 by National Energy Efficiecny & Conservation Authority (NEECA), Islamabad encouraged adoption of energy-efficient considerations in the household and promoted energy-efficient HVAC and lighting practices in buildings. It also promoted energy-efficient building design and supported to ensure compliance with the Building Code of Pakistan. According to this code, the indoor temperatures to be maintained in commercial buildings with HVAC systems are not less than 25°C in summer and not more than 22°C in winter.
To date most of the thermal comfort studies are conducted in temperate region, few in subtropics and very few in tropics . In sub-tropics, studies have been conducted in India, China, Taiwan, Japan, and Australia, etc. in different buildings. This area in Pakistan has been almost neglected so far. A few studies on thermal comfort were conducted in Pakistan with adult subjects in offices and commercial buildings, and the use of building controls (windows, doors, and fans) in relation to the thermal environment is analyzed for predicting the occupants’ behaviour. Indoor thermal comfort, comfort perception and satisfaction of residents in free-running reinforced cement concrete houses in Quetta have been explored. It was found that behavioural adaptation could help for energy conservation. A Haveli (traditional villa) in Peshawar perfomed well with the temperature swings, lowering the ambient temperature and providing occupants with various comfort zones in hot summer rather than modern residences.
Government of Pakistan took some steps in recent years for the energy saving, efficiency, and conservation in buildings but their implementation remains a challenge. After the 18th amendment in the constitution of Pakistan, the federal government cannot directly intervene in several sectors, where provincial governments must act and implement the laws. In Pakistan, the first-ever leap towards energy efficiency was made through Building Energy Code of Pakistan (BECP) in 1990. The code was adopted version of ASHRAE Standard 90.1 and focused several areas for the energy-saving and efficiency however, its implementation remained a challenge. With the changing lifestyle and technological adaptations, there was a need to revise the building energy code keeping in view the scientific and technological developments.
In 2011, Energy Provisions (EP) were developed to be included in the existing Building Code of Pakistan (BCP), which were included in BCP in 2013. EP-2011 mainly focus on commercial and industrial buildings and residential sector is being ignored. To implement the EP-2011, it was proposed to establish energy regulation authorities at the provincial and local levels. So far, only in Punjab province, an authority is established in this regard. No such efforts have been taken in other provinces and federally administered areas of Azad Kashmir and Gilgit-Baltistan.
The implementation of any regulation related to buildings can only be done with the help of local authorities. Unfortunately, the majority of local governments’ lack of infrastructure, manpower, and experts to understand the building codes and implement in their jurisdiction. Government of Pakistan introduced some measures towards energy savings such as free distribution and reduced prices of energy savers to replace incandescent bulbs. This measure was quite successful and yielded some good results. In another step, an energy labeling system was introduced for the fans. There is a need to introduce energy-saving certification for all daily life and household appliances.
Hence, there is dire need of research in thermal comfort in Pakistan for exploring the potential of reducing energy consumption in the built environment and improving the thermal comfort of occupants which can lead towards their well-being, physical health and better work performance. Thermal comfort in other buildings like kindergartens, schools, universities, residential buildings, hospitals, healthcare facilities, and elderly centers, etc. also needs to be studied.
Also, there is a need for creating awareness about energy usage and savings in the masses. Some awareness campaigns were and are being run, yet there is a need to educate more and more people. The measures for the energy sector in Pakistan like reliance on renewable energy sources rather than fossil fuels, strengthening the institutional framework regarding energy efficiency in provinces and at local level, focus on manpower, capacity building and expert’s involvement in energy sector, introduction of energy labeling and certification system for daily life and household appliances and availability of sustainable materials including buildings materials are the need of time.