Fresh Air Unit (FAU)
A Fresh Air Unit (FAU) is a dedicated HVAC component that draws outdoor air, filters it, and conditions it (cooling and dehumidifying in summer) before distributing it to the occupied space. Unlike a recirculating AHU that primarily recycles indoor air, an FAU specifically handles the outdoor air ventilation requirement.
In Indian office design, FAUs are increasingly specified alongside fan coil units. A strategy known as Dedicated Outdoor Air Systems (DOAS). This allows FCUs to handle sensible cooling loads while the FAU maintains fresh air rates independent of cooling demand. For WELL Building Standard compliance, fresh air delivery rates and filtration (minimum MERV 13) are measured and documented. Projects in high-pollution urban locations like BKC or Andheri East particularly benefit from well-designed FAU filtration.
Related terms
Learn more
Certifications and Standards Relevant to Indian Commercial Interiors
How Fresh Air Unit (FAU) fits into an office project
Fresh Air Unit (FAU) matters when a workplace moves from a broad design idea to a coordinated brief. The team should define what the term means for this project, where it appears in the drawings or specifications, and who approves it. That prevents a familiar word from hiding a gap in scope, procurement, installation, or handover.
Questions to settle early
- What outcome should Fresh Air Unit (FAU) support for the people using the workplace?
- Which drawings, schedules, samples, or calculations will confirm the requirement?
- What needs to be coordinated with architecture, interiors, MEP, technology, or building management?
What to record in the project brief
Record the selected approach, responsible owner, approval point, relevant exclusions, and the evidence required at installation or handover. If the requirement affects cost, lead time, maintenance, safety, comfort, or future flexibility, state that connection plainly. The definition is a starting point. The project brief turns it into a checkable decision.
A practical checklist for Fresh Air Unit (FAU)
When Fresh Air Unit (FAU) appears in a workplace brief, avoid treating it as a standalone line item. Connect the requirement to the people, spaces, services, and operating routines it is meant to support. A short definition is useful for orientation. A good brief also explains the project context, the expected performance, and the evidence needed before approval.
Before design sign-off
Confirm the existing site condition and any landlord or building-management rules that affect the decision. Mark the requirement on the relevant plans and schedules. Check interfaces with adjacent trades, access for installation, maintenance access, replacement cycles, and the effect on the programme. If alternatives are possible, compare them on whole-life suitability rather than headline purchase price alone.
At procurement and handover
Keep the approved specification, supplier information, samples or calculations, and agreed exclusions together with the project record. At handover, verify that the installed result matches the approved design and that the client receives the information needed to operate and maintain it. This makes Fresh Air Unit (FAU) a useful control in delivery, not just a glossary phrase.
For a project-specific discussion, start with the Vektor Spaces services, review the delivery process, and bring the relevant questions to a project enquiry.
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