All HVAC systems in homes and commercial buildings are designed to create a controlled temperature within the space. This includes pumping or blowing in hot or cold air to maintain the temperature within the room or building at a designated level.
This seems very straightforward and even simplistic, but in large spaces or in rooms or venues with high ceilings, the behavior of the air in the space is actually working against this operation. This is due to a naturally occurring event known as thermal stratification.
Thermal stratification is layers or horizontal bands of air that are at different temperatures. The hot air is lighter than cool air and rises, while cooler air falls. The amount of difference in temperature in these bands can be up to 1.5 degrees Celsius per vertical foot, with the taller and larger the building, the more significant the total temperature difference.
Destratification
To address this issue, destratification fans are used to create air circulation. The hot air from the top layers is pushed down, cooling as it drops and creating a natural vertical air circulation. This is not the same effect as a typical fan, which may blow the air within the band or just in a limited space throughout the facility.
Breaking up the layers or bands of different temperatures in the air through the use of destratification fans helps to save on the cost of heating and cooling. Eliminating hot and cold zones and areas means the HVAC system cycles on less frequently and runs for a shorter duration of time as there is limited temperature change.
While destratification fans are not usually required in most standard ceiling heights for residential properties, in larger venues such as churches, gyms, warehouses, entertainment venues, manufacturing facilities or other areas where ceilings are 20 to 40 feet in height, they are extremely effective at reducing overall and year-round HVAC energy costs.