Reducing your energy costs by moving air?
20 November 2023
THE DARK days of November tell us we are slowly heading towards winter. They are not only shorter, but also darker, wetter and colder.
As the manager of a production facility's warehouse, you want to keep your employees comfortable and productive – so you may need to turn up the heating. However, you don’t want to do this at the expense of a much higher energy bill!
There are several solutions for effectively controlling your energy costs. A relatively simple approach is through use of HVLS fans. HVLS stands for 'high volume low speed'. These industrial ceiling fans are designed to circulate air slowly, in a more efficient and effective way than previous systems. With their unusually large blades (sometimes over seven metres long) they circulate large amounts of air. They work by sucking air from above the fan, then pushing it down towards the floor and, from there, outwards to the walls.
A remarkable characteristic is that these large fans are able not only to keep employees cool in summer but to help heat the warehouse in winter. In doing so, they use a so-called destratification process. We will come back to that later.
Besides distribution centres and production facilities, these industrial fans are often used in fitness clubs, conference centres and food halls.
We know that air moving at a certain speed acts as a refreshing, cooling breeze. Air movements generated by HVLS fans are an ideal supplement to your air conditioning in summer, meaning it doesn’t need to work as hard. As well as making the air feel up to 10°C cooler, they can reduce your energy consumption by as much as 20% in the summer months. However, this blog post appears in November, so now we are more interested in benefits related to heating.
When heating our industrial buildings, inefficiency challenges are never far from our minds – largely because warm air rises. This can result in temperature differences between floor and ceiling levels in buildings with high ceilings (such as warehouses or factories). To get to the desired temperature at floor level, you would have to turn the heat up just a bit more – and make the upper level warmer than it needs to be. That is of course undesirable.
Destratification provides the answer. This is a fancy word for a smart but simple intervention. The powerful blades of our HVLS fans are shaped to move above-average amounts of air. Their design is tapered at the tip, where blade speed is higher, and wider towards the hub, where more blade area is required due to the lower blade speed.
Aspects like the angle of the blade are also important, because of the range of rotation. There may therefore be considerable differences in performance between different fans. Optimally performing fans are great at mixing the warmer air at the top of the building with the cooler air on the work floor to achieve a more even temperature throughout the room.
The results can be spectacular: you can increase the temperature at floor level by up to 8⁰C while reducing energy consumption by up to 30%! Typical payback times vary between six months and two years. After that, the fans contribute directly towards your bottom line!