Ventilation feasibility
in minutes — not hours.
Upload an architect’s drawing and receive an early-stage ventilation feasibility report for RIBA Stage 1–2 — indicative airflow, room and equipment schedules, assumptions and manufacturer-enquiry information.
Includes one free drawing analysis. No credit card required.
REFERENCED TO AD F & L · BS EN 16798-3 · CIBSE GUIDE A
See how it works in 30 seconds
Upload the drawing
Upload a drawing or input room data manually
Confirm project info
Review and confirm the extracted rooms, building type and classification
Generate the feasibility pack
Produce the early-stage feasibility report with airflow, schedules and assumptions
Send for quotation
Share the report with your consultant or manufacturer for review and quotation
From input to report in seconds
Watch VentCalc extract rooms, calculate airflow, and produce a feasibility schedule referenced to AD Part F & L — automatically.
Manual vs VentCalc
- ✗30–60 minutes calculations
- ✗Spreadsheet errors
- ✗No standard output
- ✓2–5 minute output
- ✓Part F aligned results
- ✓Export-ready report
Engineering Review Remains In Control
VentCalc generates structured feasibility assessments. Engineers review, adjust and approve outputs before export.
VentCalc interprets project information and generates a structured feasibility assessment.
The engineer reviews airflow assumptions, room schedules and project-specific requirements.
The engineer approves the output before PDF and Excel exports are generated.
VentCalc is an engineering support tool.
All outputs must be reviewed and approved by a qualified engineer.
Who uses VentCalc?
M&E Consultants
Run rapid feasibility checks before committing to detailed design. Generate SFP-checked duty points for early-stage reports and client presentations.
- → Airflow and pressure at concept stage
- → SFP checked against AD Part L2 Table 6.9
- → Manufacturer enquiry–ready output
Contractors & Estimators
Size equipment for budget quotations without waiting on a consultant. Get indicative AHU duty points in minutes, not days.
- → Central AHU, MVHR, and extract sizing
- → Equipment space estimates included
- → Excel workbook for cost build-up
Architects
Support early-stage coordination and plant space planning before detailed building services design begins.
- → Indicative plant space requirements at concept stage
- → Supports building services coordination
- → Reduces late-stage design changes
Built for UK building services professionals
Compliance standards referenced
Whole-building ventilation rates, extract flow rates by room type, intermittent and continuous strategies.
SFP limits for central AHUs and local units. Checked automatically against duty point on every calculation.
Occupancy-based fresh air rates (l/s per person) used as secondary check against ACH-governed results.
Duct sizing and pressure loss methodology. Darcy-Weisbach friction loss applied to indicative duct runs.
Engineering review and approval required prior to implementation.
What you get
Professional A4 report. White background, black borders, PASS/FAIL highlighted. Suitable for design-team review and manufacturer enquiry.
Clean, no-fill workbook: Summary, Fan Systems, Airflow Breakdown, Assumptions. Drop straight into your own company template.
Plain text export with PASS/FAIL written as text. Import into any tool, database, or cost plan.
This is what you receive
View a sample report generated by VentCalc using demonstration data.
Manual entry built for engineers
Use HVAC room presets — Kitchen, Wet Room, Office, Plant Room — to auto-fill Part F flow rates. No table-hunting, no formula typos.
| Manual method | VentCalc.AI manual wizard |
|---|---|
| ✗ Flipping through Approved Document F PDFs | ✓ Referenced to Approved Documents F & L — applicable requirements must be confirmed by the project engineer. |
| ✗ Hand-typing flow rates from rate tables | ✓ Room presets auto-fill l/s and ACH targets |
| ✗ Excel formulas prone to typo errors | ✓ Built-in logic validation flags inconsistencies |
| ✗ SFP checked manually against Part L tables | ✓ SFP calculated and checked instantly |
| ✗ Output formatted in your own template | ✓ 📋 Professional PDF + Excel generated in one click |
- ✓ Indicative airflow (ACH + occupancy methods)
- ✓ Whole-system SFP — checked vs AD Part L2
- ✓ Duct sizing (velocity & friction loss)
- ✓ Equipment space estimates with clearances
- ✓ Manufacturer enquiry duty points
- ✓ RIBA Stage 1–2 feasibility reports
- ✓ A separate, non-statutory early-stage feasibility allowance (20%)
- ✓ PBSA classification — ADF Volume 1 vs Volume 2
- – Detailed duct design & terminal pressure drops
- – Attenuator sizing & acoustic verification
- – Fire strategy & smoke control design
- – Coordination clash detection
- – Regulatory compliance and Building Control sign-off
- – BMS & controls integration
VentCalc reports are issued for early-stage design support, manufacturer enquiry, and budget costing. They are not compliance certificates or final design specifications. Final sign-off remains the responsibility of a qualified engineer.
Typical Applications
VentCalc asks the user to confirm whether student accommodation is a hall of residence/cluster arrangement, a self-contained dwelling, or mixed/uncertain, then applies the corresponding feasibility basis (Approved Document F Volume 2, Volume 1, or a review-required flag).
Early Beta Access
VentCalc is in beta. Founding-user pricing will be offered after the beta.
Reduce time spent preparing ventilation feasibility assessments.
Early-stage feasibility · Budget costing support · Coordination support
Try VentCalc free
For engineers, contractors and consultants evaluating VentCalc during beta
- ✓ One free drawing analysis
- ✓ No credit card required
- ✓ Founding-user pricing will be offered after the beta
Outputs are indicative for feasibility and early-stage design. Not a compliance or construction-ready design.
USED FOR FEASIBILITY / RIBA STAGE 1–2