Sizing an air purifier for a health screening phlebotomy bay

Key takeaways

• A phlebotomy bay differs from the waiting hall in size, dwell time and how closely staff and clients interact.
• Required clean-air delivery rate equals floor area multiplied by ceiling height multiplied by a target air changes per hour figure.
• Procedure-adjacent spaces generally warrant a higher air changes per hour target than a general waiting area.
• Sizing the bay separately avoids either under-covering it or over-specifying the whole floor to compensate.
• A full-floor survey is worth requesting once individual room figures raise questions about how zones interact.

Why the phlebotomy bay differs from the general waiting hall

A health screening centre's waiting hall is a large, open space where people sit at a distance from each other, often for a variable amount of time before being called. A phlebotomy bay is smaller and more enclosed, with a client seated close to a phlebotomist for the several minutes it takes to draw blood.

This closer contact, combined with the bay's smaller floor area, means the same air changes per hour figure applied to the waiting hall will not necessarily suit the bay. A smaller room reaches a given air changes per hour target with a lower clean-air delivery rate than a large hall would need, but the closer, more frequent contact argues for a higher target figure in the first place.

Treating both spaces as one combined figure risks under-covering the bay specifically, since its higher-risk characteristics get diluted into the hall's larger, lower-risk average.

Applying the CADR formula to a smaller, higher-turnover space

The sizing formula stays the same across any room: required clean-air delivery rate, measured in cubic metres per hour, equals floor area in square metres multiplied by ceiling height in metres multiplied by a target air changes per hour figure. What changes for the phlebotomy bay is which inputs you use.

Measure the bay's actual floor area rather than estimating from the wider screening floor's total footprint. A typical bay is small enough that a compact unit, such as the Fillo Plus, may already meet the required clean-air delivery rate once you run the numbers, rather than needing a larger unit sized for the whole floor.

Our size calculator takes these inputs directly and maps the result to the right AIRE model, so you are not left doing the arithmetic by hand.

Recommended ACH for a clinical procedure-adjacent bay

General clinic spaces are typically sized around five or more air changes per hour, while dental and procedure rooms are sized higher, around six or more, given the closer contact and higher-risk activity involved. A phlebotomy bay sits closer to the procedure end of this range than a general waiting hall does, given the close, repeated contact between staff and clients throughout the day.

This does not mean the bay needs to match a full dental operatory's target exactly, since blood draws differ from aerosol-generating procedures. It does mean defaulting to the standard clinic target of five air changes per hour, without adjusting upward for the closer contact, likely undersizes the space.

If you are unsure where your bay sits on this range, our clinic air purifier guide covers how air changes per hour targets are typically set across different clinical room types.

Coordinating sizing across the whole screening floor

Once the phlebotomy bay is sized correctly, look at how it sits alongside the rest of the floor. A screening centre often has several distinct zones, a general waiting hall, a phlebotomy bay, consultation rooms and sometimes a separate results area, each with different floor areas and different realistic occupancy patterns.

Sizing each zone individually, rather than applying one figure across the whole floor, usually gives a more accurate and often more cost-effective outcome overall. A large waiting hall might need a higher-capacity unit such as the Pro 800S, while the smaller phlebotomy bay is adequately covered by a compact unit.

Keep a simple record of each zone's floor area, ceiling height and target air changes per hour figure, so future sizing decisions, if the floor is reconfigured, start from documented numbers rather than memory.

When to request a full-floor survey instead

If your screening centre has several zones with different shapes, shared walls, or open sightlines between the waiting hall and the phlebotomy bay, a room-by-room calculation done from a floor plan can miss real-world airflow quirks that only show up on site.

A full-floor survey lets someone measure each zone in person, check ceiling height where it varies, and account for how open or enclosed each space actually is, rather than working from assumed dimensions. This becomes particularly useful when you are sizing several zones at once and want the total picture to make sense as a package, not just as isolated figures.

Request a free room-by-room Air Report if your floor has more than two or three zones to size, since the coordination across zones is often where the real value of a survey shows up.

Next step

Run your phlebotomy bay's dimensions through our free Air Purifier Size Calculator to get a starting figure, then request a full survey if your screening floor has several zones to coordinate.

Frequently asked

Why does the phlebotomy bay need separate sizing from the waiting hall?

The phlebotomy bay is smaller and involves closer, more sustained contact between a phlebotomist and each client than the general waiting hall does. Applying one combined figure across both spaces risks under-covering the bay specifically, since its higher-risk characteristics get averaged into the hall's larger, lower-risk footprint.

What ACH is appropriate for a procedure-adjacent bay?

A phlebotomy bay generally sits closer to the higher end of the clinic range, above the standard five air changes per hour used for general waiting areas, given the close and repeated contact involved. It does not necessarily need to match a full procedure room's target, since blood draws differ from aerosol-generating procedures.

Should sizing be coordinated across the whole screening floor at once?

Yes, sizing each zone individually and then reviewing how the figures sit together usually gives a more accurate result than applying one blanket figure to the whole floor. A full-floor survey is worth requesting once you have several zones to size, since it accounts for real-world airflow that a floor plan alone can miss.