FabricAir® Defrost Duct™

Up to 75% energy savings on defrosting

Efficient defrosting enables quicker restart of cooling cycles. This prevents room temperature fluctuations and preserves the stored goods better, while saving up to 75% energy on the defrosting.

A typical medium sized commercial freezer evaporator coil produces 46,000 BTU/h of cooling, which is the equivalent of an energy consumption of 10,950 watts. The total energy consumption of the unit’s defrosting process comprises the energy used to melt the ice, as well as the energy used to cool the coil back to below freezing and to remove the heat, which was introduced into the space during the defrosting cycle. The two latter are known as the recovery factor.

The duration of a defrost cycle depends on the operating conditions and defrosting method used. Without a FabricAir® Defrost Duct, there are typically four defrost cycles per day, with a duration of between 30 and 45 minutes. In this time frame, the unit is not cooling, and heat used in the coil defrosting process escapes into the room, consequently causing the room temperature to climb. As a result, the unit uses extra energy to cool the room and unit back down. Hence, the savings potential is significant compared to the low pressure drop added by using a FabricAir® Defrost Duct

The new and improved FabricAir® Defrost Duct increases the efficiency of cold storage air coolers. When the evaporator reaches its defrost cycle, the FabricAir® Defrost Duct collapses, thus effectively seals the outlet. By preventing heat escaping the air cooler, the efficiency of the defrost cycle is significantly increased.

Efficient defrosting has a positive effect on the necessary number of defrost cycles per day. Feedback from end-users verifies that the duration between defrost cycles is much longer when using FabricAir® Defrost Ducts. Depending on the model of the air cooler unit, defrostingenergy consumption is reduced by 50 to 75%.

Through clever use of materials, the FabricAir® Defrost Duct hinders water droplets caused by the defrosting cycle from freezing on the fabric surface. Adding the duct results in a slight pressure drop causing a slight drop in supplied air volume (up to 10% depending on the fan characteristics), which is more than compensated for when considering the benefits of using the solution. Adding the duct will also increase the air throw, resulting a better mixing and a more even temperature, which in turn has a positive effect on the durability of the stores good.


  • Reduces defrosting time by 10 to 50% depending on operating conditions.
  • Energy savings of up to 75% depending on equipment and operating conditions.
  • Better preservation of stored goods.
  • Prevents room temperature fluctuations.


  • Low pressure drop.
  • Longer throw length.
  • Prevents water droplets caused by defrosting from freezing on the fabric.