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Tool 2 of 8 — about 30 seconds

How many air purifiers does this room actually need?

Enter the floor area, pick the room type, and we calculate the required Clean Air Delivery Rate (CADR) and show you the exact unit count from our range. No marketing approximations — straight ACH × volume maths.

Room details

Pick a room-type preset to load the typical target ACH for that use case, or override manually.

Calculated room volume & required CADR
Volume
168
Required CADR
840 m³/h

Formula: Required CADR = Floor area × Ceiling height × Target ACH. Target ACH values follow each standard's published guidance. The recommended unit count then rounds up to satisfy the target.

Recommended options

Three configurations that hit your target. Rounded up so you don't underspec.

Get a quote on this configuration →
The product range

Airflow & coverage at a glance

Rated maximum airflow for each unit in our range, with the room size it covers at the common standard ACH targets. Coverage assumes a 2.8 m ceiling — the calculator above adjusts for your actual height.

Unit Max airflow (m³/h) Office (4 ACH) Classroom (5 ACH) Dental (10 ACH) Price (ex VAT)
MAXVAC MEDI 4e
HEPA H13 + carbon + UV-C
380 34 m² 27 m² 14 m² £184
MedicAir Pro Mini
HEPA H14 + UV-C
410 37 m² 29 m² 15 m² £532
MedicAir Pro
HEPA H13 + UV-C
605 54 m² 43 m² 22 m² £1,133
MAXVAC MEDI 8
G3 + HEPA H13 + carbon + UV-C
800 71 m² 57 m² 29 m² £450
MAXVAC MEDI 10
Alpaire HEPA + Steribreeze® UV-C
1,300 116 m² 93 m² 46 m² £1,378
MedicAir Pro Max
HEPA H14 + UV-C
1,500 134 m² 107 m² 54 m² £2,249

Figures are rated maximum airflow (units run quieter below max). Coverage assumes a 2.8 m ceiling; taller ceilings reduce it proportionally — the calculator above handles this automatically. Prices ex VAT.

How this calculation works

Standard ACH × volume — no inflated CADR, no marketing assumptions.

The formula

Room volume (m³) =
  Floor area × Ceiling height

Required CADR (m³/h) =
  Room volume × Target ACH

Unit count =
  CEIL(Required CADR ÷ Unit CADR)

Where the targets come from

  • BB101 classrooms — 5 ACH equivalent (CO₂ < 1500 ppm at 30-pupil occupancy).
  • HTM 03-01 NHS wards — 6 ACH for general wards, 10+ for high-risk.
  • HTM 01-05 / SDCEP dental — 10 ACH for AGP surgery fallow reduction.
  • HSE HSG258 offices — 4 ACH baseline duty-of-care.
  • ISO 14644-1 cleanrooms — 20 ACH Class 8, 60 Class 7, 150 Class 6.

Why "we recommend" not "you need exactly"

Real-room CADR delivery is reduced by 10–25% by furniture, partitions, intermittent occupancy, and supply-air mixing inefficiency. We round unit counts up so you hit the target on a bad day, not just on a calm-air test bench. If your room is unusually open-plan or unusually obstructed, talk to us before ordering — we'll do a free CFD-light estimate.

Got the unit count? Now get the quote.

Share the calculator output and your floor plan — we'll confirm the spec, price it in your currency, and ship a 30-day trial unit so you can verify on your real-world airflow.

Email sales@uvc-vtm.co.uk +44 (0)1462 473820