Greenhouse Focus Warming up to Biomass The successful conversion to biomass heating has presented some challenges for this 80,000 square foot greenhouse. In the end, hardwood pellets provided an answer. By Heather Hager the long term, it’s not always the easiest pro- cess and may require a lot of experimenting and fine-tuning. Brothers Scott and Ben Lin- deboom of Lindy’s Flowers in Dunnville, ON, should know. They installed a Decker Brand multifuel boiler rated for 3.5 million BTUs into their family-run greenhouse in the spring of 2006. Since firing the boiler, they’ve tried sev- eral fuels and learned quite a bit about boiler mechanics. “The motivation behind the move to bio- Not mass was the rising energy prices,” explains Scott Lindeboom. “We went with the Decker boiler because of the automatic feed and auto- matic ash removal. A place our size could not afford to have someone standing around full time to keep the boiler going. We just don’t everything worthwhile is easy. Take the switch to biomass. Although often beneficial over The red grain auger is used to fill the grain bin (foreground) with wood pellets. The wood pellets are fed directly into the boiler via a gravity-fed auger system. Heat is stored in the heat storage tank behind the boiler building and used at night. Photos: Dave Harrison/GHC. have the square footage to justify that.” The system is automated via a touch-pad control panel, and the facility and controls are set up to allow the convenient installation of a second boiler. The system combines a gravity- fed fuel supply with a boiler, an economizer, and a heat storage tank. “The economizer takes a lot of dust out of the air and brings the stack temperature of the boiler down from about 500ºF (260ºC) to about 250ºF (120ºC),” says Lindeboom. The economizer uses the extra heat to warm the cold water before it enters the boiler, making the boiler more efficient. Dur- ing the warmer months, the heat storage tank stores the heated water during the day when the greenhouse is warmed by the sun. The The Decker Brand multifuel boiler features automatic in- feed through the back and automatic ash removal from the bottom right. Photo: Heather Hager. 10 CanadianBIOMASS stored heat is used at night to keep warm air circulating and to vent the humidity, reducing mildew problems in the greenhouse and keep- ing the plants healthier. The Lindebooms first started burning oat hulls in their Decker system “with pretty good success for the first couple of months.” However, changes to the manufacturer’s pellet recipe caused the fuel to plug the boiler. They then burned anthracite coal from Pennsylvania for about a year and a half. It flowed through the bin and into the auger quite well, burned clean with low sulphur and emissions, and kept the boiler fairly clean. The main draw- back, however, was the amount of ash. “Be- cause we had so much ash, we thought maybe there’s a better way,” explains Lindeboom. Wood chips were not an option because they will not flow through the gravity-style grain bin without plugging. But the brothers MARCH 2009
Canadian Biomass March 2009: Page 10
