New Straits Times: Staying ‘coolth’ without the air-conditioner
New Straits Times, 20th March 2010
By Marc Lourdes
Original Article here
2010/03/20
KUALA LUMPUR: “Coolth” is not a word often heard.
But, in the rainforests of Sabah are chalets which use natural coolth — defined as the state of being a pleasantly low temperature — to totally do away with air-conditioning.
The Borneo Rainforest Lodge, which has 31 chalets, is cleverly designed to maximise benefits of natural breezes and minimise the effect of sunshine.
Arkitrek Sdn Bhd director, Ian Hall, who refurbished the chalets along green architecture principles, said the main trick to achieving coolth was by keeping the sun out and giving the chalets a lot of natural ventilation.
The result? An average daily temperature of about 29º C e l s i u s.
One of the reasons the low temperatures could be achieved is because the ceiling is insulated with a 10cm-thick layer of mineral wool.
Natural ventilation is allowed via holes in the floor and ceiling.
“This helps the air to flow upwa rds, ” Hall said, adding that the chalets were thus on stilts.
He added that other holes in the walls allowed cross ventilation to circ u l at e .
The bathroom, unlike the rest of the timber chalet, is built out of concrete.
There is a reason behind this, too.
“When placed in the sun, concrete absorbs and stores warmth. Similarly, when in the shade, it absorbs and stores coolth,” Hall explained, adding that the sun was not allowed to shine on concrete or anything else that stores heat.
Hall said in this case, the concrete bathroom, which is sheltered in the middle of the chalet, acts as a cooling factor for the entire unit.
“It retains coolness at night and releases it during the day,” Hall said.
In Petaling Jaya, photographer/ videographer Mark Fallander is thanking his ceiling insulation for turning his home into an oasis of coolness during this unrelenting heat wave .
“It’s been tough leaving the house these last couple of weeks.” Fallander, 53, said it cost h im RM2,600 to put up insulation three months ago.
And while he still uses air-conditioning, he doesn’t have to lower temperatures as much.
| Arkitrek Sdn Bhd director Ian Hall has refurbished the Borneo Rain Forest Lodge to maximise the benefits of natural breezes. |
29ºC is actually the maximum daytime temperature inside the chalet, misquoted in the article as the average.
The lowest temperature would be the night time ambient temperature which is usually around 24ºC thus making the average about 27ºC
How does blanketing the ceiling with wool cools the interior?
Thanks.
Hi Alan, mineral wool insulation in the ceiling of tropical buildings keeps the heat of the sun out. It is especially important in single and two storey buildings where more than half of the heat gain in the building from the sun comes through the roof. In taller buildings, apartment blocks for example, heat gain through the walls becomes more of an issue.