Climate change has stopped being a theory that we read about in books and is now a harsh reality. Human influences are thought to be the main cause behind the rise in global temperatures.
Global warming is defined as the gradual increase in the overall temperature of the earth’s atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide and other pollutants. This has resulted to rising sea levels, stronger hurricanes and storms and greater frequencies of floods and droughts.
Extreme weather conditions are likely to become the new normal.The summers are getting hotter and the winters colder. There is need to ensure our buildings are well adapted to climate change to ensure an efficient indoor climate control. Ideally, the level of thermal comfort indoors should be maintained regardless of the fluctuating weather conditions on the outside with little or no use of mechanical devices.
Houses are built primarily with the intent of providing shelter from harsh weather conditions. Careful thought as to how you build your buildings envelope may be the difference between a relaxed and productive atmosphere and the discomfort that arises from a dissatisfying thermal environment.
The sun is an important source of renewable energy available today and the best part about it is that it is absolutely free and clean. Right from the design stage, one can take advantage of solar energy by ensuring the design of your house permits maximum entry of solar energy in the form of heat in the winter and minimum entry during summer.
This is what is referred to as passive solar heating and it has everything to do with how you orient your building on site, and how you determine the position and size of your windows.
The rule of thumb is to locate your windows on the side that is facing the equator.
That means that for a building located in the northern hemisphere, the general direction to receive sun throughout the day would be to face the windows towards the south but if it is located within the southern hemisphere, face the windows of the structure to the north.
East/west facing windows are normally avoided since they will experience the most solar heat gain and glare from direct sunlight entry but if you must have them, either minimize their sizes or provide for appropriate shading methods.
In the equatorial location, if solar heat gain is to be avoided, the main windows should face either north or south, depending on the exact site location.
You can never go wrong with trees.A part from aesthetics, trees will not only provide adequate shading for your building hence reducing solar gain especially in the hot afternoons but ensures further cooling takes place when water evaporates from the leaf surface.
Go for deciduous trees since they block the sunlight in the summer and allow us to receive the much needed warmth and light during the cold days.
They are also a natural air conditioner since they absorb carbon dioxide and potentially harmful gases such as carbon monoxide from the air and release oxygen.
Trees can also be used as windbreakers by reducing wind speed and subsequent loss of heat from your home. Heat transfer through a buildings envelope takes place through conduction, convection and radiation.
Ideally, heat will flow from an area of high temperature to lower temperature. The greater the temperature difference, the greater the heat flow through an assembly.
To make a building more comfortable, we need to impede these modes of heat transfer. Insulators placed between conductors will slow down heat transfer. The materials used to make a buildings elements are worth taking into consideration in order to adequately address the issue of thermal comfort.
Metals such as steel and aluminum are the most common conductors. Their greater rate of heat flow can be taken advantage of as pathways for heat to flow to colder areas. The key is in moderation, know where to use which material and how to best take advantage of its thermal properties or lack thereof.
This article was first published under the heading “Not too hot, not too cold” and has since been edited
A construction project management professional based in Nairobi, Kenya. Reach me on: firstname.lastname@example.org