The FrostBoss A24 incorporates all the features of the 2010 FrostBoss C-49. These are the same cabinet design, gearboxes, Auto controller, ambient wind shut off, wireless temperature probes, and an optional Caterpillar or Perkins engine. The difference between the FrostBoss A24 and the FrostBoss C49 is the fan assembly
The FrostBoss A24 utilises traditional 2 blade technology, comprising aluminium alloy blades and a teetering hub. The alloy blade is made by an extrusion process and this dictates the shape of the blade profile. The pitch and twist of the A24 blade was designed to allow the fan to run efficiently at a lower engine speed, relative to the traditional 2 blade fans. This matches the fan speed with the economical speed of a diesel engine and allows the fan to run slower and hence more quietly. This fan was developed in early 2000 and there are many in use both in NZ and overseas.
The A24 is designed to run at an engine speed of 2100 rpm, using the same ratio gear boxes as the C49.This gives total interchangeability between the A24 and the C49 and means that the fan can be upgraded to a C49 at a later stage if the grower requires more coverage, or the noise rules in the growers district become tighter.
The coverage of the A24, at approx 5 – 7 ha, is about a hectare less than the C49, depending on the shape of the block and the surrounding terrain. However for the smaller block, the A24 can provide the most economical frost protection solution.
The noise produced by the A24 is about 6 dB greater than the C49 and this makes it inappropriate to use in some locations. In some districts the noise rules will be made more stringent in the future, so it is handy to know that the A24 could be made quieter if the need ever arose.
The A24 fan is retro-fitable to most brands of 2 blade frost fans. The only thing that needs to be changed is the engine speed, which the service technician would do when changing the fan.
