Stonehealth announces switch to renewable diesel for its DOFF range of masonry-cleaning equipment

Photo: Stonehealth

Conservation and restoration pioneers Stonehealth announced in May the conversion of its DOFF range of cleaning equipment to run on hydrotreated vegetable oil (HVO), also known as renewable diesel.

All future machines sold by the Gloucestershire company will be able to run on the ecofriendly fuel, while the many hundreds in use around the U.K. and globally are now able to be retrofitted, according to Stonehealth.

The move comes partly in response to requests from contractors in anticipation of an industry move towards cleaner fuels given that restoration projects are often undertaken in urban environments where air quality is paramount.

Brian Crowe, founder of Stonehealth, which recently launched the DOFF III—the latest iteration of the iconic superheated-water cleaning system—said tests had shown HVO was working equally well, with improved cleanliness and no impact on core-operation temperatures.

He cited U.S. DOE figures, which show an 86 percent reduction in greenhouse gases (GHGs) when using biofuel, but confirmed that the machines would still run on diesel or kerosene where price was a key factor.

“[Renewable diesel] is slightly more expensive than normal diesel,” Crowe said. “But the ecological benefits are clear, and we know that end clients are starting to factor emissions into project awards for our contractors. For example, one of our contractors in the Netherlands is aiming to win a contract with the Dutch government, which has stipulated that diesel is not permitted on the project in question.”

Crowe added that other contractors in the U.K. are also finding that promoting the ecobenefits of their solution is a factor in winning work with public and private organizations.

“This is particularly relevant in urban environments, where air quality is a significant issue and where pollution causes damage to heritage buildings,” he said. “So we know this move is happening across the industry. We wanted to get ahead of the curve and preempt the demand becoming more commonplace.”

Research and development for the HVO conversions have been undertaken by the engineering team at Stonehealth, which is based in Cam, near Dursley.

Crowe confirmed that tests had shown all existing iterations of Stonehealth machinery—three models of the DOFF machine, as well as the Torc cleaning system—could be converted to run on biobased diesel.

“Our team is able to retrofit older models if necessary,” he said. “We’ve done the tests and the machines work really well on this fuel. So we’re excited to offer this new development as our company continues to lead the way in the careful restoration of our nation’s heritage buildings.”