IMPORTANT FACTS:

1.   Return Air Ducts and Grilles are the most common items under sized in a Ducted Air Conditioning system. Most contractors will undersize these items as it makes the installation cheaper and without asking most people would not realise this until after 3 years of it not working correctly they finally call someone else in to inspect it only to be told the entire duct layout is incorrect and/or too small. We have seen 22kw ducted systems with 1 x 500mm duct and a 900mm x 500mm grille which then runs very inefficiently and noisy. If they appear on paper to be offering you the same system as the next company but cheaper then most people will accept that. Recommended Return Air Grilles and Ducts listed below:

CAPACITY:                          DUCT SIZES:                                                     GRILLE SIZE:

7kw to 11kw                       1   x   400mm                                                      1  x  750mm  x  500mm

12kw to 14kw                     2   x   350mm                                                      1  x  900mm  x  500mm

15kw to 19kw                     2   x   400mm                                                      1  x  950mm  x  550mm  or  2  x  600mm  x  450mm

20kw to 27kw                     2   x   450mm                                                      1  x  1200mm  x  600mm  or  2  x  750mm  x  500mm