The primary purpose of a building is to prevent the occupant from the vagaries of nature. Since ancient times, humans have evolved this dwelling space from open living spaces like jungles to closed spaces like caves, upgrading from thatched roof settlements during the Neolithic times to the present urban concrete jungles of present times. With each upgrade, modification, mankind has found itself being challenged by multifarious issues related to building spaces. In the past decade, the issue of heat as a consequence of global warming has been among the greatest cause of concern in the building industry.

Buildings are open systems which interact with the surroundings,exchanging heat and mass.They are physical systems exposed to agents of nature like sunlight, rainfall, wind, etc. Each of these agents interact uniquely with the building systems. A fair understanding of the processes is a sine-qua-non to finding solutions. The primary purpose of a building is to provide environmental comfort so that its occupants can conduct their jobs effectively without hindrance. In order to go about performing the daily tasks by an occupant without any discomfort, it is essential to provide thermal comfort. Thermal comfort is described as the state wherein the occupant feels neither too hot nor too warm, a state of thermal equilibrium. Although assigning a definite temperature to it would be a function of geography/location of origin of the occupant, the goldilocks are assumed to be 28-32 degrees centigrades. However we must take into account the thresholds for individual capacities for heat resistance as a function of other parameters like age, gender, macro climate as well. Achieving thermal comfort is crucial for maintaining occupant satisfaction, productivity and overall well being in various indoor spaces like residential buildings, schools, offices, community halls and other public buildings. India, which falls under a diverse bio geographical location stretching from the Himalayan ecosystems in the north to desert ecosystems to the west, from tropical rainforests and oceans in the south to the parched dry lands of the eastern plateau, must keep into consideration the factors affecting its building dynamics.

Factors on which thermal comfort is dependent upon:

Among the comfort indices, we have to divide the parameters into two- environmental and personal

• Environmental parameters :

1. Mean radiant temperatures (MRT): refers to the average of temperatures of all the surfaces surrounding a person in an indoor or outdoor environment. It includes the temperatures of walls, floors, windows and other objects which dissipate heat.
2. Air temperature: refers to the thermal energy of the surrounding air. Its entry can increase/decrease the ambient temperatures depending on its thermal reading.
3. Humidity; a measure of moisture in the air. The more the temperature of an air column, the more is its capacity to retain moisture.
4. Air speed: corresponds to the flow of air in a building apparatus.

• Personal parameters :

1. Metabolic rate: refers to the rate at which a human body produces heat through metabolic processes. It usually varies according to age, gender, physical activity, and overall health of individuals.
2. Clothing: has an imperative on heat being felt by humans.Clothing insulation prevents heat dissipation in cold climates while light coloured clothing prevents heat absorption by the fabric in hot climates.

Heat transfers in buildings: heat always travels from warm to cool areas.This primarily happens through three ways as follows 

•  Conduction: The heat transfers through a solid medium due to the temperature difference.The two things required for conduction to take place are surface contact and temperature difference.

e.g : an  uninsulated  wall  exposed  to  high  outdoor  temperatures  can  conduct heat into the building, causing increased indoor temperatures and discomfort.

•  Convection:  This form of  heat  transfer  involves  energy transfer  by  fluid movement  and molecular  conduction.

e.g. warm outdoor air  in tropical climates  infiltrates through cracks or gaps in the wall, it can convectively transfer heat into the building, leading to increased indoor temperatures.

•  Radiation: The heat transfer through electromagnetic radiation. Any surfaces at differing temperatures that face each other will emit and absorb radiant energy continuously.

 e.g: sunlight passing through a window brings radiative heat into the room, contributing to an increase in indoor temperatures.

The above three processes in conjunction raises the temperatures of buildings in peak summers by as high as 55%.The heat gain and heat storage to a building can disrupt the thermal comfort. The heat gain in a building envelope attributes to the heat storage capacity in the thermal mass elements. Heating and cooling equipment balances this to maintain comfortable conditions for the occupants. In the tropical climate of India, increases in the cooling load of buildings is of greater concern having bearing on energy bills,climate and environment.

The cooling load of a building refers to the amount of heat energy that needs to be removed to maintain thermal comfort in a space. Cooling loads are classified based on their impact on  the temperature and moisture content of the air:

• Sensible cooling load:  caused by changes in the air temperature and  is  felt  as  the  warmth  of  the  air. The  sensible  heat  load  includes  conduction  and radiation heat gain through the building envelope and from the internal load of occupancy, lighting, and equipment.

• Latent cooling load: This type of heat load is caused by changes in the moisture content of the air without changing the temperature and is related to the amount of water vapour in  the  air. The  main  sources  of  latent  load  in  a  building  are  from  building  occupancy, infiltration and equipment contributing to the addition of moisture content in the air.

The cooling load can be further classified based on their source

• Building Envelope : Load relates to heat gain through building envelope components like walls, fenestration, floors, and roofs of a building.
• Transmission heat load: This type of heat load is caused by heat transfer through the building envelope, including walls, windows, roofs, and floors.
• Infiltration heat load: This type of heat load is caused by air entering or leaving the space through cracks, gaps, and other openings in the building envelope.
• Thermal  bridge  heat  load:  This  type  of  heat  load  is  caused  by  the  presence  of materials  or  components  with  higher  thermal  conductivity  within  the  building envelope. These  materials and elements  create  localized  areas  of  increased  heat transfer, leading to higher heat flow than in the surrounding insulated regions.

Internal Load

a.  Occupancy  Load:  The  occupancy  load  represents  the  heat  generated  by  the occupants within the space.The number of people present, their activity level, and their metabolic rate influence the amount of heat produced.

b. Lighting Load: The lighting load represents the heat generated by artificial lighting sources, such as incandescent, fluorescent, or LED lamps.

c.  Equipment  Load: The  equipment  load  refers  to  the  heat  generated  by  various electrical  and  mechanical  equipment  used  within  the  building.  This includes computers,  servers,  kitchen  appliances,  refrigeration  units, and other equipment that releases heat during operation.

In the context of the above,LuminX presents a complete and comprehensive solution to counter the heat build up.