Three steps. No CAD training.
If you can sketch on a whiteboard, you can produce a professional HVAC design.
Draw the plan
Walls chain and snap to the grid — or press Enter and type the exact length. Closed walls become rooms automatically, with net floor area measured wall-to-wall.
Get the loads
A block cooling-load engine turns every room into BTU, kW and airflow — accounting for glazing, occupancy, room type, design temperatures and multiple storeys.
Send the quote
Units auto-size from your own price catalogue. Pipe runs, diffusers and ducting land in a costed bill of materials with VAT — exported as a branded PDF.
Design, size, route, price — one canvas.
Walls-first floor plans
Chain walls, snap to grid or geometry, type exact lengths, lock directions with arrow keys. Closed loops become rooms by themselves.
Live cooling loads
Per-room BTU/kW and supply airflow update as you draw — glazing, people, room types and design ΔT included.
Equipment auto-sizing
Loads snap to real catalogue capacities with diversity applied. Under- and over-sized units are flagged instantly.
Refrigerant piping
Route multi-split runs corner by corner, add vertical risers the plan can't show, and get exact lengths with wastage.
Costed BOM & quotes
Your own equipment pricing per project, pipe and diffuser costs, per-room breakdowns and a VAT-ready total.
Branded PDF reports
Letterhead, floor plans, room schedules, duct & diffuser schedules and the quotation — one export.
Multi-storey buildings
Replicate a typical floor or design each level separately — the roll-up and quote follow automatically.
Share & comment
Send clients a read-only link. They pin comments straight onto the drawing — no account needed.
Numbers you can defend.
- Component-level breakdown: walls, glazing, roof, solar, people, lighting, equipment and ventilation — in watts, converted once.
- Net clear floor areas (walls inset by half their thickness), not inflated centreline areas.
- Positive-pressure rooms for server rooms and cleanrooms, with offset airflow.
- Design QA flags open walls, units outside rooms and unconnected pipes before your client does.
The BOM prices itself.
- Load your own price list per project — the quote uses your numbers, not ours.
- Pipe totals split horizontal vs vertical runs, with configurable spare percentage.
- Per-room and per-system breakdowns, duct and diffuser schedules included.
- One click to a branded PDF: cover, floor plans per storey, schedules, quotation.
Start free. Upgrade when it pays for itself.
One quote won on time covers years of Pro.
Free
- 2 projects
- Full floor-plan editor
- Live cooling loads & airflow
- Equipment auto-sizing
- Pipe routing & costed BOM
Pro
- Everything in Free
- Unlimited projects
- Branded PDF reports & quotes
- Client share links & comments
- 3D building preview
Questions, answered.
Is the free plan really free?
Yes — two projects with the full editor, live loads and the costed BOM, forever. Pro adds unlimited projects, PDF export, client share links and the 3D view.
Do I need CAD experience?
No. Walls draw like a whiteboard sketch — click, aim, click. Snapping keeps everything square, you can type exact lengths, and closed walls turn into measured rooms automatically.
How are the cooling loads calculated?
A block cooling-load method computes each room from its envelope: wall and glazing conduction, solar gain, roof, occupancy, lighting, equipment and ventilation — with a safety factor, shown in BTU/hr, kW and m³/h. It's built for fast, defensible estimates; it does not replace a certified Manual J submission where one is required.
Can I use my own equipment prices?
Yes. Each project can carry its own catalogue — models, capacities, prices and pipe rates — so the BOM and quotation always reflect your supplier pricing.
Can my client see the design?
On Pro you can share a read-only link — no account needed on their side. Clients can pin comments directly onto the drawing and you'll see them on your next open.
Is there a Windows desktop version?
Yes — Ventdraft also ships as a native Windows application with the same design engine and file format, so projects move between desktop and web.
Your next quote could take 10 minutes.
Draw it, size it, price it, send it — before the competition has opened their spreadsheet.
Start designing free