Yet another German horticultural business has recently made the switch from sheet steaming to sandwich-type steaming using a steaming hood, and the results are impressive.
The business – which is based near Stuttgart in the Federal state of Baden-Württemberg – had been operating successfully for more than 10 years using sheet steaming, and wanted to take a step forwards towards greater energy efficiency.
Under the guidance of MSD GmbH the business took the step and, instead of procuring a new sheet, it opted for two steaming hoods used in sandwich-type steaming. Instead of guiding the steam under a sheet which is weighted at the edges, the sandwich-type steaming method utilises a special steaming hood equipped with spikes, which drive the steam into the soil to a depth of up to 25cm. The business made the decision to initially operate the hood manually. This involves a single operator lifting and lowering the hood using a lever construction, and moving it while positioned on wide rollers.
The result was worth it. The savings generated in comparison to sheet steaming were close to 50%. Instead of almost 6,000kg of steam, the horticultural business only requires just over 3,000kg of steam per greenhouse with a surface area of 260m² and a steaming depth of approx. 25cm, for a target temperature of more than 80°C. This equates to a very cost-effective steam requirement of approx. 12 kg per m². Consequently, energy costs when measured in today’s price for heating oil are below EUR 0.5 per m².