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Best AI for HVAC Design in 2026
Last reviewed: November 2026

HVAC design starts with the load calculation, and every drawing downstream depends on it: unit tonnage, airflow per room, diffuser counts, duct sizes, and the equipment schedule on M-601. The repetitive part comes after. Mechanical teams redraw ductwork and diffuser layouts every time the architect moves a wall or the ceiling height changes, re-check outdoor air against IMC Section 403 or ASHRAE 62.1, and confirm that a rooftop unit still has the service clearance IMC Section 306 calls for and that its intake sits far enough from exhaust under IMC Section 401.4.

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The shortlist

Top picks for HVAC Design

  1. 1Load calculation software: Carrier HAP and Trane TRACE 3D PlusMechanical engineers producing design loads, airflow, equipment sizing, and ASHRAE 90.1 energy runs for commercial buildings
  2. 2NomicMechanical engineering firms that want a new source of drafting capacity once the loads are done, including background updates and existing conditions
  3. 3h2xMechanical engineers who want loads, layout, and sizing in one model, exported to AutoCAD or Revit
  4. 4Design Master HVACMechanical engineers drafting in AutoCAD who want duct sizes and calculations to stay with the drawing through revisions
  5. 5MagiCAD Ventilation and PipingMechanical designers modeling ventilation and hydronic systems who want pressure drop and air terminal selection on the modeled objects

Rankings

5 tools ranked for hvac design

01

Load calculation software: Carrier HAP and Trane TRACE 3D Plus

The calculation layer for commercial HVAC loads, system sizing, and energy modeling

Best for: Mechanical engineers producing design loads, airflow, equipment sizing, and ASHRAE 90.1 energy runs for commercial buildings

  • Carrier HAP uses the ASHRAE Heat Balance method, sizes by system type, and runs 8,760 hour energy analysis from the same model
  • Trane TRACE 3D Plus is built on the US Department of Energy EnergyPlus engine and integrates with Autodesk Revit
  • Both are long-established in commercial mechanical practice and familiar to reviewers
  • Output feeds the airflow and equipment data every downstream drawing depends on

Pricing: Carrier HAP about $1,995 per license in the US; Trane TRACE by quote

02Built by Nomic

Nomic

AI drafting for ductwork, diffuser, and mechanical piping plans and schedules, saved as DWGs and checked

Best for: Mechanical engineering firms that want a new source of drafting capacity once the loads are done, including background updates and existing conditions

  • Lays out ductwork, diffusers, and mechanical piping from architectural backgrounds, reflected ceiling plans, and equipment cutsheets
  • Sizes duct runs to the friction rate or velocity criteria your engineer sets and draws equipment schedules in Excel and on the sheet
  • Checks each drawing against the code edition you name, such as the IMC, ASHRAE 62.1, and ASHRAE 90.1, and against the load report and other source documents
  • Reads rooftop unit and air handler nameplates from site walk photos to build existing conditions DWGs

Pricing: Free; Individual $20/mo; Business $40/user/mo (25 seat minimum); Enterprise custom

03

h2x

Browser-based HVAC design with room loads, live duct and pipe sizing, and a new AI Design Assistant

Best for: Mechanical engineers who want loads, layout, and sizing in one model, exported to AutoCAD or Revit

  • Calculates room-by-room heat loss and heat gain, then sizes ducts and pipes with Darcy-Weisbach pressure loss
  • Finds the index run and fan and pump duties, with heat maps for velocity and pressure drop
  • Exports AutoCAD files mapped to your layers and blocks, Revit models, and a ductwork schedule in Excel
  • The Design Assistant, launched in November 2026, lays out designs while the h2x calculation engine runs every number

Pricing: Contact h2x for current pricing

04

Design Master HVAC

AutoCAD add-in that ties ductwork drafting to airflow, sizing, pressure loss, and load calculations

Best for: Mechanical engineers drafting in AutoCAD who want duct sizes and calculations to stay with the drawing through revisions

  • Draws single-line and double-line ductwork and connects diffusers, with a diffuser schedule generated as you design
  • Sizes an entire system with one command and recalculates when the layout changes
  • Calculates pressure loss and highlights the critical path
  • Runs heating and cooling loads with the building defined over the architect’s backgrounds

Pricing: $104/seat/month for a dedicated license

05

MagiCAD Ventilation and Piping

HVAC and piping design modules with calculations for Revit, AutoCAD, and BricsCAD

Best for: Mechanical designers modeling ventilation and hydronic systems who want pressure drop and air terminal selection on the modeled objects

  • Pressure drop calculations on modeled duct and pipe systems
  • Air terminal selection can use throw length limits for each space
  • Large manufacturer product library through MagiCAD Cloud
  • Runs on both Revit and AutoCAD

Pricing: Quote based on modules, users, and license model

Frequently asked questions

Answers to common questions about this comparison.

Start with load calculation software such as Carrier HAP or Trane TRACE 3D Plus, because loads drive every other decision. For drafting ductwork, diffuser, and piping plans as DWGs with a code check, Nomic. For layout and sizing in one model, h2x, Design Master HVAC in AutoCAD, or MagiCAD in Revit or AutoCAD.

Use dedicated load calculation software for design loads. h2x calculates room loads with its own engine and keeps AI away from the numbers. Nomic does not run load calculations or energy models; it drafts and checks the drawings against the load report and the criteria your engineer sets.

Yes. Nomic lays out ductwork and diffusers from the architectural background and reflected ceiling plan, sizes runs to your engineer’s criteria, and saves the plan as a DWG in your standards. h2x and Design Master also lay out and size ductwork, with the designer placing the runs.

Nomic checks its own drawings against the code edition you name, such as outdoor air rates under the IMC or ASHRAE 62.1, equipment access clearances, and intake separation from exhaust, and lists open questions. The mechanical engineer of record reviews the findings and makes the final call.

Nomic does not edit Revit models. On Revit projects it delivers DWGs plus a change list that a modeler links into the model, and it can review the drawings and schedules the model produces.

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