Quality Counts – and so far the quality design and construction has brought the production total of Farm Electronics motorised louvres to over 6000 units.
First built in 1981 the louvre specification has been improved over the years but the basic concept as a purpose designed weatherproof louvre which is insulated, virtually airtight and light proof remains unchanged.
Quality materials are of course used throughout but much of the real practical advantage comes from the overlapping and interlocking blades which are individually spring loaded to ensure positive closure. Brush seals are then used to further limit air leakage past the blades.
Motorised louvres are used to provide positive air control in both ambient and refrigerated cooling systems since Farm Electronics firmly believe in the benefits of combining the ambient ventilation and refrigeration cooling systems.
Combined systems also avoid the additional costs of separate ventilation systems and perhaps most importantly it ensures that the high air volume necessary for crop drying and ambient cooling is also used for refrigerated cooling.
Air leakages are also an important factor in deciding the initial refrigeration plant capacity and ultimately the plant efficiency since warm outside air entering the store by whichever route will increase the cooling requirement on the system. To illustrate the quality of the motorised louvre and in particular the low air leakage rate, Farm Electronics commissioned the ADAS Crop Storage Unit, based at Silsoe, to carry out air leakage tests on a number of stores.
David Barlett, the Senior Consultancy Engineer at Silsoe carried out the tests using carbon dioxide as the marker gas and charting the decline in gas level and therefore the air leakage rate over a period of several days and in a number of different stores in both still air and windy conditions. We were also interested in the effect of fan operations during these tests and whether they influenced the air leakage rate in any way.
The results were very satisfactory both for us and for the farmers in whose building the tests were carried out. Even old buildings had very low and entirely acceptable air leakage rates.
This series of tests and the report prepared by David Bartlett confirmed our confidence in the Farm Electronic Louvre which are very effective in resisting air leakage. The allowances made for leakage in our refrigeration design calculations are much greater than the actual air leakage rate.