Airflow is a subject dear to Charlie Strange’s heart. As the facilities director for a Texas facility operated by HVAC manufacturer Goodman, he helps oversee the production of heating, ventilation, and AC units in the world’s fifth-largest factory building — 4.2 million square feet of space, all dedicated to the generation of hot and cold currents and gusts.
But when the pandemic forced Goodman to send thousands of workers home, Strange had to consider airflow anew — specifically, how the eddies and flows inside his Texas plant would affect the work of his latest hire: a cleaning robot named Breezy One that trundles around the gargantuan factory, spraying a fine mist of virus-killing disinfectant onto the surfaces. For office managers looking at a pandemic-tinged future, such considerations could well become routine.
“This robot’s going to be able to clean 200,000 square feet of office and conference rooms in two, maybe two and a half hours,” Strange tells The Verge. “It would take my team all night long to do that — wiping down every surface by hand.”
When Strange unpacked the Breezy One, the first tasks he and the machine’s creators, Build With Robots, had to tackle was a contaminant study — finding out exactly where the bot’s disinfectant mist could clean. To carry out this study, technicians dropped test plates around the plant populated with microbes taken from the compost heap of Kimberly Corbitt, Build With Robots’ head of customer engagement.
“It’s the worst smelling thing you’ve ever smelled in your life,” says Corbitt of her compost. “I dilute it in a giant pitcher of water, put it into a spray bottle, then spray it onto these foam plates. The first time I did it, the total viable count was out of the testable range and I had to dilute it by a factor of 100. My compost is really healthy.”
Each plate is divided into two halves: one side covered and the other side uncovered. Once the plates have been placed, Breezy One does its thing, spreading a mist of disinfectant around the area. The next day, technicians check to see what percentage of microbes have been killed off, comparing the uncovered half of the plates with the covered half as a control sample. In essence, they’re checking that the disinfectant is getting everywhere it should.
This is why airflow is important, says Strange, as his team had to account for the building’s air conditioning units when checking the spread of the disinfectant around its offices and meeting rooms. “We might slow down the robot or change the route based on the dispersal pattern because of the HVAC or how high the ceiling is,” he says.
Thankfully, Goodman found that Breezy One worked as advertised. “The dispersal pattern on it is very nice, it mists very well, which means [the disinfectant] floats and can get into all those areas,” says Strange. “That’s one of the reasons you want the airflow in the room going, because it helps deliver it around the room, rather than having it shoot straight up and fall straight down.”
The robot itself is about the size of a bulky trash can, with a wheeled base and two large mist-producing jet nozzles on top that stick out like a pair of swiveling eyes. It moves at a steady walking pace, using a combination of LIDAR and 3D cameras to navigate like a self-driving car. And it’s not the only robot making its way into these sorts of shared spaces.
Cleaning machines have come into fashion with the pandemic. Hospitals around the world have been deploying them since the spring, using robots that radiate ultraviolet light to kill germs and viruses rather than “foggers” like Breezy One. Airports and arenas are getting in on the action, too, with the latter using drones that spray disinfectant over stadium seating. Now it seems offices are next. The demand certainly seems to be there, with one US manufacturer, Xenex, saying sales of its UV cleaning robots are up 600 percent compared to 2019.
Melonee Wise, CEO of Fetch Robotics, the company that makes the autonomous base of Breezy One, tells The Verge that interest in disinfecting robots has taken off swiftly. She says the two main types of machines — UV emitters and foggers — are suited to different markets, with the former better suited for small rooms and the latter working best in larger spaces.
Robots like these will become staple fixtures “in any area that has a large amount of the general public filtering through,” predicts Wise. “There’s just a large need to provide continuous disinfection.” She says, although the pandemic has prompted many companies to investigate these machines. If the robots prove their effectiveness, they’ll likely become a regular part of cleaning operations even after COVID-19 is under control.
“Whether or not it’s COVID, there’s always going to be some next viral thing coming through that [companies] will want to disinfect,” says Wise. “We’re looking at having one at our headquarters for flu season, for example, as I would guess maybe 30 percent of staff ends up out because of flu.”
“I think people should be demanding that these things are in their offices,” she adds.
Some buyers certainly see the robots as investments for an uncertain future. Pamela Ott, deputy city manager for Pleasanton, an affluent city in Alameda County, California, purchased three UV cleaning robots for operation in various government facilities — the city permit office, the library, and senior center — and says she thinks they’ll be useful long beyond the duration of the pandemic.
“We purchased the robots because we know they’re helpful now and helpful in the long run,” Ott told The Verge. “We look around and we look ahead, and we don’t think COVID is going away, certainly not in the very near future…. And we know any time we can better clean and disinfect our facilities, that’s a good position for us.”
Ott says each of the three machines she purchased from local distributor SNAP Solutions cost around $99,000 but that the price was worth it. “It’s a significant outlay for a city, but it’s our belief that our purchase of the robot is one of the most important steps we can take to ensure the safety of our employees and community members,” says Ott. The makers of Pleasanton’s new cleaning robots, Blue Ocean Robotics, say they’ve sold to a number of customers for use in offices and that interest has also spiked from hotels in recent months.
Gauging how effective these machines actually are at protecting people from COVID is difficult, though. Build With Robots, maker of the Breezy One, claims that the disinfectant its machines use kills 99.9999 percent of bacteria, as well as the novel coronavirus. (The chemical solution in question is a brand known as Aeris Active.) But killing the virus by cleaning surfaces is not the same as safeguarding real-world environments from COVID-19.
Scientists know that the virus that causes COVID-19 is spread through respiratory droplets — small droplets of saliva, mucus, and other internal fluids that are created when we cough, sneeze, talk, or simply breathe. But the most common ways for these droplets to spread the virus from person to person is still a matter of ongoing investigation. Current evidence suggests that COVID-19 “spreads easily” when people are in close contact with one another, while transmission via contaminated surfaces is “less common,” according to the Centers for Disease Control and Prevention. And that means wearing masks and stopping people from crowding together is likely to be more important for hygiene purposes than cleaning desks, door handles, and other surfaces.
Despite this, those buying robots for surface cleaning hope the machines will at least help more than they harm. Strange says that his robots are at least saving the company money. Although Goodman won’t share exactly what it’s paying for Breezy One, Build With Robots says the cost for hiring its machines is between $3,250 and $10,750 a month, depending on the number of robots and the length of the contract. Strange also adds that no workers have been or will be let go because of the machines and that they’re simply taking on work that would have been done during overtime by human staff.
What Strange says is most impressive, though, is how easy it is now to integrate this sort of technology into an ordinary office like those used by Goodman. “I’ve dealt with a lot of automation over a lot of years and I’ve yet to find an honest-to-god fire and forget,” he says. “But if we’d been talking five, seven years ago I’d have had a team of four to keep this thing running. And now I’m just going to have one person moving it from zone to zone. It’s amazing how far we’ve come.”