Chances are, you’re reading this in an urban heat island.
You might not know that word – or the abbreviation, UHI – but you probably know what one feels like.
It’s the way that the climate changes in a hot country when you enter a built-up area. The effect is clearest in high summer, deadliest at night.
The problem is that when we built our cities we didn’t always consider how they might trap the sun’s heat.
Dark road surfaces cook during the day. Tall glass façades blast the sun’s rays down to the ground. And then machines and traffic exacerbate the problem with their own waste heat.
It’s tough for quality of life but for global warming it’s truly terrible. Not just directly. The problem is that once a UHI sets it, it triggers a vicious cycle.
It work like this. A UHI can raise temperatures significantly. In Bangkok, for example, a study has found that it can add 6-7°C to heat during the dry season. So we naturally use our AC more – especially at night, when a UHI can put an end to normal nighttime cooling.
The problem is that AC units contribute to urban heating too. For each of 1 ton of cooling they give your home, they will likely pump out 1.4 tons of heating to the outdoors.
So, of course, we use our AC more. So we heat up the city more.
It all fuels a looming crisis for power use. By 2050 energy expended worldwide for cooling is forecast to overtake energy used for heating.
At The Forestias, of course, we’re doing it very differently. The whole area, in fact, is designed as an urban ‘cool island’.
Doing this involves many separate precautions. We must create a lot of shade, plant a lot of trees, and ensure roofs and roads don’t soak up sun rays.
We’ve also designed a district cooling system, so conventional AC condensers will spread no heat outdoors. This will work in combination with energy-efficient buildings and elements like ‘up-flow stack ventilation’ in tall buildings.
Outside the residential areas, a lake will provide overnight cooling. A forest canopy will help keep in the cooler air during the day in a ‘cool basin’. You are likely to feel the temperature drop by about 3°C as you walk into this zone in the south of The Forestias from the Bangna Trad highway.
Unlike a UHI, you probably haven’t experienced an urban cool island before. But we’re confident that you –and the planet – will like it.