How Your Drawing Should Look
Prepare your DXF before conversion. Clean centerlines, clear layer names, and proper size labels help DuctDraft AI produce better results.
Reduce manual HVAC duct drafting time from hours to minutes. Upload your single-line HVAC DXF file and get a fully drafted double-line output — complete with duct walls, elbows, branch shoes, reducers, endcaps, layer-matched colors, and a detailed conversion report.
From upload to a CAD-ready double-line drawing.
See the full single-line to double-line conversion in a 55-second walkthrough.
Enter the layer names — for example, SA, RE, EA, or FA.
Select the duct type — for example, Round, Rectangular, or Chilled Water.
Upload up to 3 DXF files. Maximum file size: 25 MB per file.
Select the shaft to set flow direction
The engine traces centerlines, identifies connected runs, and groups them by service type.
Text labels and leaders are matched to their corresponding duct runs to assign cross-section dimensions.
Branch shoes, elbows, inline reducers, and endcaps are constructed at every connection point.
A structured summary shows every layer, run, fitting count, and any warnings before you download.
Save the converted double-line DXF file — fully layered and ready to open in any CAD application.
Download Sample ConversionThe converter performs best when your DXF follows clean, consistent drafting standards. A few minutes of preparation can prevent most conversion warnings.
Prepare your DXF before conversion. Clean centerlines, clear layer names, and proper size labels help DuctDraft AI produce better results.
AI-generated output can contain mistakes. Always have a qualified engineer or CAD team review and verify the drawing before it is released.
Open the downloaded DXF in AutoCAD or your preferred CAD application and visually scan each duct service layer.
Inspect every branch shoe, elbow, reducer, and endcap. Confirm placements align with the original single-line intent.
Cross-reference generated duct widths against the original size annotations and leader notes in the source drawing.
Have a qualified CAD drafter perform a final QA review and apply any project-specific drafting standards before issue.
Common questions about uploads, conversions, billing, and file handling.
DuctDraft AI currently supports DXF files. The maximum upload size is 25 MB per file.
UploadsEach file that completes processing and produces a downloadable result counts as one conversion. Failed conversions are not counted.
ConversionsYes. Each successfully processed file inside a batch counts as one conversion.
ConversionsNo. Selecting a file, detecting layers, previewing, or choosing shaft points does not use your conversion allowance.
ConversionsYes. Files uploaded through ductdraftai.com are transmitted over HTTPS. The backend must process the drawing to generate converted files and quantity takeoff results.
UploadsUploaded drawings and generated output files are stored temporarily for processing and download. They are removed automatically after the configured retention period.
File handlingNo. Customer drawings are not used to train AI models.
File handlingUploaded drawings are not routinely reviewed by staff. Limited technical access may be possible for system maintenance, troubleshooting, abuse prevention, or support when required.
File handlingYes. Download links are temporary because generated files are removed after the retention period. Links may remain available only while the generated file still exists on the server.
File handlingYes. Customers can manage billing and subscriptions through the billing portal when available from their account.
BillingNo. Unused monthly conversions do not roll over. Usage resets at the beginning of the next billing cycle.
BillingYou can contact support at support@ductdraftai.com.
BillingQuestions about a conversion, a plan, about drawing or report Send us a message.
We usually reply within a day. For anything urgent, reach out directly.