For contractors
Mechanical design software for contractors.
Work through duct and pipe layouts over a PDF plan, check sizing assumptions and prepare clearer design questions. MEPFlow supports practical mechanical design iterations in the browser.
A changed route, equipment position or fixture arrangement can raise questions that a marked-up PDF alone cannot answer. MEPFlow gives contractors a way to explore the supported design calculations in the context of a layout. Use it with the responsible designer and the project requirements to assess alternatives before installation.
Review Radiant Floor Loop Layouts
Explore spiral and serpentine circuits, manifold positions and feed routes over the project plan. Inspect full loop lengths, floor output and circuit flow, then use the plan and 3D views to discuss routing, exclusions and installation requirements with the designer.
Explore Underfloor HeatingCheck the effect of a duct route
Lay out the proposed branch and air-terminal connections on a scaled drawing. Review the assigned airflow and selected dimensions, then inspect the available pressure information after applying sizing. An alternative route can require a different fitting or fan-pressure allowance even when the terminal airflow has not changed.
Explore HVAC duct design softwareWork through water-side equipment changes
When a coil or heating duty changes, review the design temperature difference and required flow before checking pipe size. The Hydronics workflow relates these inputs to the connected equipment and piping. Final equipment selection still needs its manufacturer data and operating conditions.
Explore hydronic pipe sizingReview sanitary slope and fall
In the Drainage module, place supported fixtures and connect gravity branches, mains and floor stacks. Review fixture units, nominal sizes, invert elevations and fall. This helps discuss the supported pipe-sizing questions; trap arms, venting, cleanouts and installation details remain separate design responsibilities.
Explore Sanitary DrainageBring a specific calculation to the discussion
Use a free duct, ventilation, domestic-water or hydronic calculator to check an individual assumption. For the saved application workflow, start with one small system and compare the result to an independent calculation. Keep the designer’s approved sizing and project revision clear when reviewing alternatives.
Open the free engineering calculatorsUseful questions to resolve before a route change
| Design change | What to revisit | Useful MEPFlow workflow |
|---|---|---|
| A duct detours around structure | Does added length or a different fitting change pressure requirements? | Duct layout and sizing review |
| A coil moves farther from the plant | What happens to circuit length, flow and pressure loss? | Hydronics equipment and piping |
| A drain route needs a lower outlet | Does the proposed invert provide the required fall and slope? | Drainage module geometry and sizing |
MEPFlow is a design-calculation workspace, not an estimating, dispatch or procurement system. Do not assume an automatic material takeoff, labor-cost estimate, fabrication drawing or purchase list. Check the actual output available in the relevant module and use the project’s required documentation process.
Practical questions before you start
Is this a consulting or installation service?
No. MEPFlow is software used by the design team. Project engineering, site verification, coordination and final approval remain with the responsible professionals.
Can I use the calculators without an account?
Yes. The public calculators and engineering guides remain free to use without signup. Start a 30-day free trial when you want a saved design project with a floor plan and connected layouts.
Can I work from an existing PDF drawing?
Yes. Apply the appropriate page to a floor and establish scale before drawing. Review the geometry, classifications and connections yourself; PDF upload does not automatically recognize the building systems.
Does it replace the project CAD or BIM deliverable?
Use the deliverable your project requires. The established distribution modules provide PDF-overlay or PNG drawings and Loads provides its report/schedule outputs. Native Revit/IFC export and a complete fabrication model are not advertised.
Is every design automatically code compliant?
No. Check the specific method, jurisdiction, assumptions and limitations. A sized network does not establish complete compliance or remove the need for professional design review.
Try it on a design you can check.
Start with a small project, confirm the inputs and calculation basis, and review how the layout and results fit your process.
30 days free. Then $50 USD/month. No credit card required.