This is part 3 of passive cooling for your home. We will look at some options that will require a bit more money.
Some years ago, having a small water feature at home was all the rage in Malaysia. You see all sorts of water feature including small water fountains, cascades and even table top fountains being sold everywhere. At that time, their popularity is due to interest in fung shui rather than for passive cooling for the house. Water features that are too small like those that fit on a table top is not effective for cooling since the amount of water and surface area is just too small to make any contribution to a cooler home. In fact, it may generate more heat due to the small electric pump.
Larger water features on the other hand do help regulate the temperature around your home. As water evaporates, it absorbs heat from surrounding air, so the air cools. On days that are dryer, the water evaporates faster thus there is a stronger cooling effect. On days that are humid, evaporation rate is slower thus the cooling effect will not be as strong.
If you are going to renovate your home, you can plan and design a pond or fountain to suite your home from the onset. You can decide on the size as well as whether you want it to be above ground or in the ground. In some homes designed from the onset to be eco friendly, you may find a large swimming pool on top of the roof. Others have large shallow ponds that surround the entire house and you need to walk on walkways to enter the house. Still others have pools that are partially indoors and partially outdoors with a wall in between. If you have a large area, you can consider ideas like these. However, do not forget safety as a priority if you have small children as water features can cause drowning.
If space is a premium or you don’t plan on making major renovation at this time, you can use large ceramic pots around 2 feet diameter and 1 feet deep. These pots can be placed at the corner of your house or even indoors. You can raised on a pedestal and make them into bird bath attracting birds to your garden. Such pots area easily available from most nurseries or garden supply shops. You may even find them in some large department stores as well. If such pots are hard to find or if you find them expensive, you can use normal gardening pots but fill the holes at the bottom with a bit of cement.
Plastic fish ponds that are meant to be place on the floor or in the ground is another option as well. They come in a variety of shapes and sizes. There is some maintenance for water features like this. Over time, the water will will attract mosquitoes and algae will slowly grow in the pond as well. You can over come these 2 problems by put a few small fish like guppies and a type of fish that eats algae. Do not put larger fish like goldfish since larger fish needs more care and also an air pump to sustain them. As long as your pot is big enough and the fish is tiny, you can avoid using an air pump. Small fishes like guppies are easy to care for.
If you think it is too much trouble to care for fish in the pond, then treat the water with Abate, an insecticide meant specifically for mosquito larvae. Put some plants like a water lily in the center since a plant will absorb some of the nutrients in the water and prevents algae from growing that fast.
Other water features like a water fountain will require an electric water pump to pump water around. It will consume a small amount of electricity. If you really do not want to use any electricity, use a small pond like the one above. While most types of water fountain require a bit of space, do not discount them if you home is small like in a condominium or a small terrace house. Some fountains require just about 1 foot in depth but the water cascades down slowly along a wall like structure. This type of fountains really helps to cool things down since the surface area for the water to evaporate is large.
I came across this type of water feature in Setia Walk. There are lots of them that line the entire place with shallow water ponds as well. As you can see, even commercial buildings are using lots of such methods to keep the environment cooler. Even though the buildings and restaurants will still need air conditioning, overall, it helps to create a cooler more comfortable living space.
The tubes in the photo above is massive and not suitable for most homes but you can create something similar that lies flat against a wall.
Not many homes in Malaysia uses aluminium sunshade for passive cooling. These sunshades allow indirect light to pass through while blocking direct sunlight. The reason we do not see more house use aluminum sunshade could be due to cost or esthetics. A house may start to look more like a commercial building rather than a nice home. It could also be due to lack of seeing other homes using it that prevents wider use of aluminium sunshade.
Anyway, there are 2 types of sunshades. Horizontal and vertical. Horizontal sunshades are designed to shade the walls as the sun is higher up in the sky between the hours of 10 am to about 3 pm. Vertical sunshades on the other hand, is more suited when the sun in low in the sky. Notice in the photo above, the vertical aluminium sunshade blocks the harsh morning sun from the window behind. Both type of sunshade have their functionality, depending on what you want to achieve.
Horizontal aluminium sunshade is used widely on commercial building since they are effective in shading the building from the sun while still allowing sufficient light. This is important to ensure that there is no increase in daylight lighting cost while much lower electricity consumption for air conditioning. As more and more commercial buildings a built to a greener standard, the savings are substantial since the air conditioner is used throughout the day. As you can see in the photo on the right, the sunshades are designed to block sunlight when the sun is high in the sky. They do not require a lot of space and yet allows natural light to light up the interior of the building.
Some aluminium sunshades are designed to be movable like venetian blinds. They can move to change the angle of the sunshade. This is a more sophisticated design and also means it cost more.
The advantages of using aluminium is that the material is light and low maintenance. It does not rust and will last a long time without requiring paint or other protective coating.
Before you consider using them, know that to produce aluminium, a lot of energy is required. Aluminium is sometimes called “stored electricity” and is not all that environmentally friendly because of the of amount of energy required to produce it. On the other hand, aluminium is wholly recyclable which means that no aluminium is lost when it is recycled. Recycling uses a lot less energy than producing aluminium from ore.
If you feel that aluminium sunshades are not that eco friendly, you can consider similar sunshades. Some are made from wood or bamboo as well. Here’s a different kind of metal sunshade that cools the house and create a visual effect as well.