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Fresh Air Supply Units (IN STOCK NOW)

Fresh Air Supply Units are commonly called FASUs or Filtered Air Supply Units. FASUs provide clean filtered air into rooms where split system air conditioning has been installed.  Most split system air conditioning units do not add any fresh air to the room. So if all the windows and doors are closed, low levels of oxygen and increased carbon dioxide will occur.

The FASU continuously adds clean, filtered fresh air to the room and is typically linked into the power for the air conditioning systems so they operate in parallel.  The FASU is also fitted with speed control to allow adjustment for the number of people and the size of the room. The units typically have 3 speeds with the medium speed being the most popular.  Like any fan unit, as the fan speed increases so does the noise output.

School classrooms are a typical installation. The Sigrist Design Filtered Air Supply Unit is compliant with the specifications of the Queensland State Government for installation statewide in schools.  Other examples are demountable buildings and offices, like site office and mine installations or whenever additional filtered air is required.

Fresh Air Supply Units come in several types with the most commonly installed being product code FASU-FT-146 and in areas of high corrosion the stainless steel version FASU-FT-146-SS316.

The “Heritage” model is the same basic dimensions but narrower for use in thin walled building applications like demountable offices.


Maintenance of the FASU is vital for it to retain it’s filtration and supply air flow.  Filters must be washed regularly and replaced when required.  The replacement product code is FILT-V-F5-412-412-90 that suits the FASU-FT-146 powder coated and stainless steel versions.

Here is a link to understand more about Air Changes Per Hour (ACPH).

Sigrist Design Australian Made and Owned

FASU-FT Fresh Air Supply Unit Documentation:

FASU-FT Quick Install Kit Fitting Guide has details of the flashing kit and how it speeds up the installation process

FASU-FT Service Guide has details of how to service your FASU quickly and effectively

FASU-FT Inspection Interval Guidelines has details of when to service your FASU

FASU-FT Filter Identification and Reorder Guide how to identify your FASU filter and get a replacement.

FASU-FT Cleanliness Guidelines with details about when your Filtered Air Supply Unit filter needs cleaning or replacing.

FASU-FT Housing Only Install Standard

FASU-FT Motor Installation Guide