By Bob Meyer
Star Business Reporter

Greenhouse growers could soon save millions of dollars annually in heating costs, thanks to a Windsor company.

Acrolab Ltd. has just patented a process that uses naturally decomposing leaves and other composites to heat greenhouses.  And that's good news for Essex County, which has the highest concentration of greenhouses in North America, filling more than 900 acres and bringing in more than $275 million annually.

"The process is as natural as leaves rotting on the forest floor," said Joe Ouellette, president and CEO of Acrolab Ltd., explaining how the new system could reduce heating costs by up to 75 per cent.
"The problem was capturing that heat energy and transferring it.  We recently discovered that heat transfer bars, which we design and manufacture for an assortment of other highly technical and scientific applications, are exactly what is needed to transfer heat from a decomposition process," he said.

Agrilab Technologies Inc. was established by Acrolab to handle research and development of a new environmentally friendly heating system.  The division's mandate is to "promote and sustain plant growth within a greenhouse, or any other structure, by generating, extracting and distributing the renewable heat energy produced by microbial decomposition of organic bio-mass within a contained and controlled environment."

"Heat transfer pipes, known technically as isobars, transfer heat a thousand times faster than a solid copper pipe," said Andrew Williams, managing director of Acrolab and a key player in the design of the revolutionary heating system.

Agrilab is able to extend the composition period from an average of 42 days to 140 days, all the while providing constant temperatures of 135 to 160 F.  "It is now possible to heat a greenhouse complex for an entire winter from the decomposition of one bio-mass pile," said Williams.

A greenhouse is a natural setting because a hot water system already exists.  The bio-waste is dumped into a decomposition chamber and the heat generated by the decomposition process is transferred by the isobars to the greenhouse hot water heating system.

The rate of decomposition is controlled by adding certain catalysts.  An individual recipe for the mixture of compost and manure is written for every greenhouse because the temperatures required vary depending on what's being grown.

What are the catalysts?

"You won't believe it, but it's manure from cattle, horse or chicken farms," said Williams.  "Another byproduct.  And there is absolutely no smell."
Agrilab is so sure of the benefits it built its own greenhouse-surrounded by homes and industries in Windsor's east end-for growing crops using heat from decomposition.  There are absolutely no side effects, he assured.
The next step will be a model greenhouse of his own, on a farm among greenhouses in the Leamington area, where the heating system will be put to the ultimate test using low-quality soil, extreme temperatures and no other sources of heat.

Marvin Shaw, who has been a key adviser in research and development, said an average greenhouse farm of 10 acres will produce around 12 tons of compost a week.  With tomatoes, the compost is leaves and stems.  With flowers, it's stems and roots.  Sweet corn nets stocks and some cobs and leaves.  Even straw can be used.

Every crop has waste composite, said Williams, and getting rid of it has always been a problem unless the grower has land where it can be plowed under as fertilizer.  Some take neering (sic) and manufacturing heat transfer solutions since 1948.  He said last winter, when many greenhouse owners suddenly found themselves paying as much as $150,000 a month on heating fuel, Agrilab's research and development became a priority.

"We can see complete return on their investment in two to three growing seasons," Ouellette said.

Now Agrilab is testing whether this could also work in commercial and residential applications.  "It's not out of the question to use isobars for transferring heat from the massive beds of materials decomposing in landfill sites."