It's so natural column

Cooling effect: Hanging plants will also add to the cooling effect of a pergola according to columnist Alan Hayes.
Cooling effect: Hanging plants will also add to the cooling effect of a pergola according to columnist Alan Hayes.

With what appears to be a hot summer on the way now is the time to consider simple and effective ways that you can improve the coolness of your home without using energy-hungry air conditioners.

The trick is to stop heat from entering your house in the first place, rather than trying to cool the air down once it is inside.

Temperature control can be as easy as growing deciduous vines over a pergola or window trellis on north or west-facing walls.

Hanging plants will also add to the cooling effect of a pergola.

Light reaching the house is filtered through the greenery and the hanging plants help to lower the surrounding temperature considerably through the moisture evaporating from their containers.

This evaporative cooling effect can be further increased by installing a drip watering system: water lines are attached to the roof framework of your pergola above the plants, letting the system drip slowly and constantly.

As the day heats up, evaporation will increase - more so on extremely hot days - greatly lowering the surrounding air temperature and increasing the cooling effect. 

Portable planter boxes on rollers make ideal window shades that will provide cool green screens for north or west-facing windows from the hot summer sun.

They can also be positioned to redirect cooling wind currents into the house during the evening. 

Portable planter boxes should be constructed from a weatherproof material such as treated pine, and can be as large as you wish them to be. However, bear in mind that it is easier to move or adjust several small planters than one gigantic one - as a general rule of thumb, and because of the likely weight of the soil, a practical maximum length would be about 1.5 metres.

The planter should also have an appropriate frame to hold up wires for climbing plants.

When choosing your plants or vines, select from varieties that are both tolerant to hot and cold weather, and that will provide plenty of dense foliage all year round.

External shades, such as roll-up awnings, are an effective and efficient way of stopping heat gain through windows.

If you're short on cash, the cheapest and simplest method of exterior shading is to hang a canvas or bamboo blind outside the window, from a roof overhang.

Leave a space for venting at the top of the support to prevent a pocket of hot air from building up.

At night the shade can be rolled up to allow cooling breezes to enter the house through the window, and in winter it can be taken down and stored away.

If wind is a problem where you live, it will be necessary to provide a ground anchor - preferably one with an elastic shock cord - to prevent flapping.

Roof venting with a wind turbine is another inexpensive and simple method of cooling.

Although ceiling insulation significantly reduces heat gain from a hot roof, venting of the roof will further reduce the discomfort of summer heat.

Good roof ventilation lowers the mean radiant temperature of the ceiling facing the interior of your home, making it cooler.

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