Temperatures inside double-decker buses will be cooler by up to 10 degrees Celsius as Kowloon Motor Bus upgrades cooling systems and installs more solar panels on the roof of its vehicles.
Developed by KMB's engineering team, the new solar panel system will cool down its buses 50 percent faster than the first-generation cooling system, treating passengers to a cooler ride as temperatures are reduced by eight to 10 degrees.
The new system will also enable KMB buses to trim fuel usage by
Ho Sai-lok, a senior engineer, said the new cooling system will be effective even under a scorching sun.
He said the number of solar panels set up on each bus has been increased from 20 to 28, and their efficiency raised by 10 percent.
They cover almost the entire roof, marking a 40 percent increase in coverage area and a 54 percent spike in the amount of captured solar energy compared to first-generation buses equipped with solar panels.
The engineering team also came up with tailor-made aluminum frames to attach the panels onto the roofs. The frames enable a thin layer of air to be generated as heat insulation to reduce temperatures inside the bus.
Another major enhancement was undertaken in the air ventilation system and subsidiary solar power supply.
When an engine is turned off, the solar energy will enable the ventilation system to extract hot air through a specially-designed duct.
With the engine turned on, the system supplies electricity directly to USB chargers and drives the ventilation fans of air-con systems and in the engine compartment.
KMB's new fleet has already passed the Transport Department tests.
Delivery will begin in the second half of next year.
KMB has yet to disclose the official launch date of its new buses. Its old solar-powered buses will continue to operate even after it introduces its new-generation units.