HVAKR

Cloud HVAC load calculation software runs in a browser, so there's nothing to install and the project lives on a server instead of someone's C: drive. The tools differ a lot in what "cloud" buys you. Some only move the file online. A few let a whole team work the same project at once. Here's what to check, and how the main browser-based options compare as of November 2026.

Why firms are moving load calcs off the desktop

No installs or license servers. Carrier HAP, Trane TRACE 3D Plus, IES VE, Elite Chvac, and Wrightsoft Right-Suite Universal are Windows desktop programs. On a Mac, that means a virtual machine.
One copy of the project. No "Loads-rev3-FINAL-JM" file on a shared drive, and no wondering which file the reviewer opened.
Review without a handoff. A senior engineer can open the live project and check it, instead of waiting for a PDF.
Updates ship to everyone. Nobody is stuck on last year's version because IT hasn't pushed the installer.

"Cloud" isn't one feature. Check these five things

Is the calculation engine in the browser, or is it a desktop app with cloud file storage? Both get called "cloud."
Can two people edit the same project at the same time? Many tools offer share links or read/write access rather than simultaneous editing. Ask what happens when two engineers change the same space.
Roles. Can you give a client or architect view-only or comment-only access without handing them edit rights?
What leaves the browser. PDF reports are table stakes. Check for CSV or Excel exports, gbXML, and an API if you want results in Revit or your own tools.
Method and paper trail. Browser tools are newer, so ask which ASHRAE method they use (RTS or Heat Balance), which edition of ASHRAE 62.1 drives outdoor air, and whether the vendor publishes a Standard 183 compliance statement.

Cloud load calculation tools compared

Each summary below comes from the vendor's own website, checked November 4, 2026. Where a vendor doesn't publish something (simultaneous editing, list price), we say so instead of guessing.

Focus: commercial HVAC design: loads, ASHRAE 62.1 ventilation, airflow, equipment, and duct layout in one model.
Runs in: the browser, plus a macOS app.
Team editing: several people can edit the same project at once. Changes sync field by field, with presence, project chat, and comments on a specific space, zone, or system (real-time collaboration docs). Five roles: Owner, Admin, Member, Commenter, and Viewer (sharing docs).
Floor plans: AI Space Takeoff finds rooms on a floor plan drawing and creates spaces for you to review (docs).
Method: ASHRAE RTS for cooling, peak picked from 288 month-hour points. Outdoor air uses ASHRAE 62.1-2022 tables. Published Standard 183 compliance statement.
Exports: PDF and CSV reports. Project data and gbXML export on Team and Enterprise.
Price: Solo $240/mo for one seat, Team $960/mo for 3 seats, less when billed yearly (pricing). 14-day trial on Solo, 30 days on Team.

HeatWise

Focus: a dedicated commercial and residential load calculator. HeatWise says energy modeling and direct Revit integration are out of scope.
Runs in: the browser.
Team editing: co-workers get read and write access to your projects. HeatWise doesn't say whether two people can edit at the same time.
Method: Radiant Time Series from the 2021 ASHRAE Fundamentals Handbook, for each hour of a design day in every month (288 samples).
Exports: PDF and Excel reports.
Price: Commercial $49 per user per month, or a $65 one-month pass. 30-day free trial (pricing).

h2x

Focus: multi-discipline MEP design: HVAC, ducts, heat loads and heat loss, hydronic heating, chilled water, domestic water, drainage, gas, fire protection, and more. h2x says it's used in 40+ countries.
Runs in: the browser.
Team sharing: Design Share sends secure, read-only links to the calculated model, and viewers don't need an h2x license (Design Share).
Floor plans: h2x launched its AI Design Assistant ("h2x AI") on November 4, 2026. Per h2x, it traces the floor plan from the architect's PDF (you check it before it goes in) and routes and sizes pipes and ducts with h2x's calculation engine. Nothing changes until the engineer accepts it. h2x's launch line is "AI never touches the numbers."
Price: not published. h2x asks you to contact sales.

MEPFlow

Focus: loads plus duct, domestic water, hydronic, drainage, and underfloor heating sizing in one connected workspace.
Runs in: the browser, with cloud projects.
Price: one plan, $50 per month after a 30-day free trial, with every module included (pricing).

HVAC Designer (hvacloaddesigner.com)

Focus: heating and cooling loads, duct sizing, and an AI chat bar that helps fill in forms.
Runs in: the browser.
Price: free for now. Its pricing page says plans are "under preparation" (pricing).

Cool Calc

Focus: residential ACCA Manual J, S, and D, not commercial design.
Runs in: the browser. House geometry can come from a floor plan upload, satellite trace, free-draw, or a LiDAR scan.
Price: pay per project or subscribe (coolcalc.com). See our Cool Calc comparison.

Trane's next TRACE

Focus: Trane describes its next TRACE as a cloud-based application built for Revit integration in collaboration with Autodesk.
Status: Trane's TRACE page says a TRACE beta is available (Trane TRACE). It's the one to watch if you're a TRACE shop in Revit.

For the desktop programs (HAP, TRACE 3D Plus, IES VE, Chvac, Right-Suite Universal), see the best HVAC load calculation software, compared.

What to test in a trial

Have two engineers open the same project and edit different spaces at the same time. Then the same space.
Share it view-only with someone outside your firm.
Change one window type on a finished project. See what updates on its own (loads, airflow) and what you have to re-run, like duct sizing.
Export the report you'd actually submit, and the data you'd push to Revit.
Run a small project you've already done in HAP or TRACE and compare peaks room by room.

FAQ

What is cloud HVAC load calculation software?

It's load calculation software that runs in a web browser, with projects stored on the vendor's servers. There's nothing to install, and anyone with access can open the current project from any computer, including a Mac.

Which HVAC load calculation software supports real-time collaboration?

HVAKR lets several engineers edit the same project at the same time, with live sync, presence, project chat, and comments on spaces, zones, and systems. HeatWise offers read and write project sharing, and h2x's Design Share gives read-only links. Ask any vendor what happens when two people edit the same thing at once.

Is cloud load calculation software accurate enough for commercial projects?

Accuracy depends on the method and inputs, not on where the software runs. Look for an ASHRAE method (RTS or Heat Balance) and a published ANSI/ASHRAE/ACCA Standard 183 compliance statement. HVAKR publishes one requirement by requirement.

Can I run HVAC load calculations on a Mac?

Yes, with a browser-based tool such as HVAKR, HeatWise, h2x, or MEPFlow. HVAKR also has a macOS desktop app. Carrier HAP, Trane TRACE 3D Plus, IES VE, and Elite Chvac are Windows programs.

Is there free cloud HVAC load calculation software?

HVAC Designer (hvacloaddesigner.com) is free while its pricing is in preparation. Most others offer trials: HeatWise and MEPFlow 30 days, HVAKR 14 days (Solo) or 30 days (Team). Check what a trial lets you export.

Sources (checked November 4, 2026)

HVAKR: pricing, real-time collaboration, sharing and roles, cooling loads, AI Space Takeoff, Standard 183
HeatWise: pricing, features, homepage fit check
h2x: homepage, Design Share, Design Assistant launch session
MEPFlow: pricing, homepage
HVAC Designer: homepage, pricing
Cool Calc: homepage
Trane: TRACE page

Cloud HVAC load calculation software: what "cloud" should mean for an engineering team