‘Fog harp’ could help ease water woes
THE fog rolling over Table Mountain could go right into your tap.
The makers of the “fog harp”‚ designed to trap water from vapour‚ say their invention could help in drought and waterscarce areas.
The fog-harvester of 700 wires on a 1m x 1m frame is still in development, but the team says the principle is well tested.
In areas where the technology is applied on a large scale‚ harvesting projects can collect as much as 6 000 litres a day‚ depending on the weather.
Capturing water in this way is normally achieved with a wire mesh net that collects microscopic droplets until they are heavy enough to roll into a collection basin.
The mesh design has been used since the 1980s‚ but the “harp” structure is new and promises a greater yield.
The problem with the net‚ scientists have found‚ was that the size of the mesh holes had to be precise. If they were too big‚ the fog passed through – too small, and water clogged them.
The new prototype‚ from a research team at Virginia Tech in the US‚ might have solved this problem.
“From a design point of view‚ I’ve always found it somewhat magical that you can essentially use something that looks like screen-door mesh to translate fog into drinking water‚” Brook Kennedy‚ one of the designers of the device and a co-author of a paper on the invention published in ACS Applied Materials & Interfaces, said. Part of the design inspiration came from looking at the Californian sequoia trees‚ whose water supply collects on their needles.
“We found the smaller the wires‚ the more efficient water collection was‚” team member Jonathan Boreyko said.
The team hopes its design will make a difference in waterscarce areas.
Researchers estimate that two-thirds of the world’s population is affected by scarcity at least one month of every year.