Cooler homeVentilating your home
By Dianne Lee, Construction Philippines

Summer in the Philippines can really be hot. Unless you have money to spend on electricity for air-conditioning, 3-months of summer can be very uncomfortable especially for infants. Generally a tropical house is built with large windows, awning and wind access on all four sides. However, urbanization has limited space thus limited ventilation as well. Worse, more and more Filipinos have lost the love for nature, particularly trees and gardens that naturally makes homes cooler and fresher.

Studies show that 75% of the heat inside your home comes through the roof. This is specially true to about 90% of houses in the Philippines which are constructed using metal roofs with low ceiling. Unlike in the provinces, homes are usually cooler because homes are near trees and the use of “nipa” definitely cools the house.

When the sun heats your roof, it radiates the heat energy into the house. In the evening, heat from the sun-baked roof and walls will begin to diffuse inside the house within a few hours. This will create a warm condition, even though nightfall has arrived.

Another reason is through heat and humidity. If you leave your windows open in summer, you will invite “hot air” to come inside your homes. If you combine this with high humidity, you will create your own steam room effect known as convection.

If you live in dense areas where you have neighbors that have low metal roof, the heat that comes from it is transferred to your house. The bake-hot concrete road also contributes in transferring some of its heat to your house. This is known as conduction where outside heat elements are transferred to your homes.

Thus your house gets heated in three ways… by Radiation, Convection and Conduction.

What you can do to reduce the heat?

1. Dress your home.
Use 2 layers of curtains, one dark to block the sun’s ray and light material when there’s less sunlight. Most household assumes that when the weather is warm, you should open your windows. This is not necessarily the case when temperature outside (full sun) is higher than inside your homes. When windows are open, heat from outside is invited to the inside when windows are left opened. The sun’s rays also should be blocked using these curtains. What you should do is to leave at least 2 windows open for ventilation and close all windows where you feel the heat are coming from.

2. Insulate your roof and walls.
Roofs should be provided with adequate insulation in order to reduce heat and conserve energy. There are insulation materials such as foam that can reduce your roof’s absorbed heat, giving you with much more comfortable dwelling. While it may cost you more to do this, eventually the savings you get from electricity will pay for itself.

Airofoam is a brand we can recommend. Its durable and high quality material will help cool your homes. Unlike other “cheap” brands, Airofoam is a composite material that combines the best of reflective and bulk insulation. Airofoam has one or two layers of reflective material and a micro-cellular polyethylene foam core.

3. Ventilate your homes
Houses in the Philippines are relatively small. As a result, most houses increase their floor area by maximizing extensions.

Even if you have 10 windows located in one façade of your house, air cannot move enough. Windows should be situated farther apart. The best is to have windows located where the breeze is (observe this during nightfall) and add a window on its opposite end. (North and South or East and West sides)

If you cannot do this, be sure to add an exhaust either on the ceiling or on the farthest corner of the house, opposite the window.

You may also open a 1×1 meter “open enclosure” where you can get the air movement vertically. Use vertical ventilation and add an exhaust fan. You will surely feel the difference.

4. Plant trees
The most practical and easiest way is to cool your house by planting trees. If you have a small space, you can still plant within a 1×1 foot of soil area. Use Mahogany trees. It is cheap, has slim body, shady leaves that does not rot easily. Its root penetrates deep and does not destroy property if you plant the seedling at least a foot deep. You can also use grafted Mango trees which doesn’t grow too big to destroy your property.

If you want a fast growing tree, plant  Mahogany or Knife Acacia trees. These trees are easy to manage and you can easily control their size. It is also not prone to pest nor will it destroy property, unless it’s a hundred years old. If you do not want a tree, you can opt to train a Bougainvillea to grow a top of your metal roof, they are excellent when it comes to shading.

You can also convert your outside premises into grass instead of tiles or concrete. An ideal house should be surrounded with soil/grass. If your outside area is a bit shady and has heavy walk traffic, Use “grass pavers” where there are wholes fitted for grass. Use Carabao grass as it can grow in a bit shady area.

 

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