Free HVAC Software in 2026: The Complete Guide for Small Contractors

Quick answer: Krib is one of the best genuinely free HVAC software options for small contractors — it includes quoting, scheduling, invoicing, online payments, and a booking widget at $0/month with no trial period. Other free options include FieldVibe (free for solo techs) and Orcatec (free with limitations). Most tools called "free" are 14-day trials or limited freemium plans.

Why HVAC Contractors Are Searching for Free Software

If you run a small HVAC company, you've probably noticed something frustrating: the software built "for you" costs anywhere from $50 to $400 per month — per technician. According to publicly available pricing pages at the time of writing, ServiceTitan charges in the range of $245–$398 per tech per month, with implementation fees that can reportedly run from $5,000 to $50,000. Housecall Pro's Essentials plan is listed around $149–$189/month for team access. Jobber charges $29/month per additional user on every plan (as of July 2026). (Competitor pricing changes frequently — verify current rates directly with each provider.)

Meanwhile, according to industry surveys, over half of field service businesses are still running on paper, spreadsheets, and phone calls. Not because they don't want software — because the "affordable" options still cost more than many small shops can justify.

The result? Contractors either overpay for enterprise tools they'll never fully use, or they cobble together Wave for invoicing, Google Calendar for scheduling, Venmo for payments, and a notebook for customer records — becoming the human glue between a dozen disconnected apps.

This guide is different. We break down every genuinely free HVAC tool available in 2026 — both business management software and engineering/design tools — and we're honest about which "free" products are actually free trials or feature-restricted freemium tiers.

Free HVAC Business Management Software

These are the tools that help you run your HVAC business day-to-day: scheduling jobs, sending invoices, tracking customers, collecting payments, and managing your team.

This is where most contractors feel the pain. The engineering side of HVAC actually has decent free tooling (we cover that below). But the business side — getting paid, staying organized, looking professional — has historically been locked behind expensive monthly subscriptions.

Here's what's actually available for free:

Krib — Free All-in-One Contractor Software

Krib is a genuinely free platform built for small contractors. No monthly fee, no per-user charges, no feature gating, no free trial that expires.

We keep the core software free primarily through standard payment processing (~3%) when you collect payments through the platform — and you can pass that fee to customers if you choose (subject to your state's surcharge laws). We're also building a future program to offer anonymized, aggregated property insight reports to industry partners — this is not yet active, and when it launches, you and your customers will always be able to opt out.

What's included at no cost:

• Professional quotes and estimates
• Job scheduling with time slots and calendar sync
• Invoicing with online payment collection
• Customer management and service history
• Technician dispatch and mobile access
• Booking widget you can embed on your website
• AI-powered equipment scanner
• Warranty tracking
• Available in English and Spanish

• Best for: Solo operators and small HVAC teams (1–10 people) who want one free tool instead of juggling five paid ones.
• Pricing: Free — $0/month, no per-user charges. Revenue comes from standard payment processing fees (~3%) on payments collected through the app. A future opt-out anonymized property insights program is planned but not yet active.

Try Krib Free

Orcatec

Orcatec offers a free tier for small HVAC businesses. It covers scheduling, dispatching, and basic invoicing. The interface is functional but can feel dated compared to newer tools.

• Best for: Contractors who want basic scheduling and dispatching at no cost.
• Pricing: Free tier available. Paid plans start around $29/month for additional features.
• Limitations: Limited reporting, basic CRM, some features require upgrade.

FieldVibe

FieldVibe is a simple scheduling app with a free plan for solo users. It focuses on one thing — scheduling — and does it well. If you only need to manage your calendar and send appointment reminders, FieldVibe works.

• Best for: Solo HVAC techs who only need scheduling (not invoicing, quoting, or CRM).
• Pricing: Free for one user. Paid plans start at $29/month for teams.
• Limitations: No invoicing, no quoting, no customer management, no payment processing. You'll need separate tools for everything else.

DoTimely

DoTimely offers a free plan with scheduling, invoicing, and client management. Originally built for pet services and cleaning businesses, it has expanded to serve HVAC and other trades.

• Best for: Contractors who want basic scheduling and invoicing in one free tool.
• Pricing: Free tier available. Paid plans for advanced features.
• Limitations: Not purpose-built for HVAC. May lack trade-specific features like equipment tracking or warranty management.

The DIY Free Stack (Wave + Google Calendar + Venmo)

Many small HVAC contractors piece together a free tech stack from general-purpose tools:

Wave — free invoicing and accounting. Unlimited invoices, expense tracking, automatic payment reminders.

Google Calendar — free scheduling. Works, but no customer linking, job tracking, or dispatch capabilities.

Google Sheets — free estimate templates. Customizable but manual — and academic research (Panko, "What We Know About Spreadsheet Errors") suggests a significant percentage of spreadsheets contain formula errors.

Venmo / Zelle / Square — free payment collection. No automatic reconciliation with invoices.

This approach costs $0 but has a hidden price: you become the integration layer. Every job requires manual data entry in 3–4 places. Customer information lives in your phone contacts. Service history lives in your memory. And when tax season comes, you're scrambling to reconcile payments across multiple apps.

If you're just starting out and doing fewer than 5 jobs per week, this stack works. Beyond that, the time cost of manual coordination starts eating into your revenue.

The Truth About "Free" HVAC Software

The biggest frustration contractors have with "free HVAC software" searches: most results aren't actually free. Here's an honest breakdown of how pricing models work in this space.

Free HVAC Engineering & Design Tools

Here's the good news: the technical side of HVAC has significantly better free tooling than the business side. Load calculations, duct sizing, and refrigerant diagnostics all have solid free options.

Load Calculation Software (Manual J)

Manual J load calculations determine what size HVAC system a building needs. Getting this right is critical — an oversized system short-cycles and wastes energy; an undersized one can't keep up.

CoolCalc

The most capable free option. Web-based, works on any device. Uses Google Maps to trace building footprints and auto-calculate surface areas. ACCA-approved Manual J8 calculations. Free to create an account and run unlimited calculations — ACCA-approved PDF reports cost credits.

LoadCalc.net

A straightforward block load calculator based on Manual J. Quick whole-house calculations without the complexity of room-by-room analysis. Good for ballpark estimates.

ServiceTitan HVAC Load Calculator

A simplified online BTU calculator for residential buildings. Not a full Manual J calculation, but useful for quick residential estimates. No account required.

HVAC-Calc

Desktop software for heating and cooling load calculations. Free demo version available with limitations on saving reports.

Duct Sizing Tools (Manual D)

Proper duct sizing ensures adequate airflow throughout a building. These free tools help you calculate duct dimensions based on airflow requirements.

Ductulator.com

Free online ductulator. Calculate duct velocity and pressure drop from design airflow. Simple, fast, no account needed.

h2x Duct Size Calculator

Calculates HVAC duct dimensions based on airflow, velocity, and duct shape. Supports both rectangular and circular ducts.

HVACRly Manual D Calculator

Simple and Advanced modes. The Advanced mode uses friction-rate based Manual D approximations for more accurate sizing.

Refrigerant & Field Diagnostic Apps

These mobile apps are essential for field technicians working with refrigerant systems.

Bluon HVAC App

The Swiss Army knife of HVAC apps. Contains 35,000+ unit manuals, pressure-temperature charts, superheat/subcool calculators, airflow diagnostics, and step-by-step retrofit instructions. The core app is free — business management packages are paid add-ons.

HVACR Check & Charge (Copeland/Emerson)

Free refrigerant charge calculator supporting R-22, R-410A, R-32, R-407C, and many more. Includes superheat, subcooling, and airflow calculators.

Ref Tools (Danfoss)

Pressure-temperature charts and essential calculation tools for refrigeration technicians. Free from one of the most trusted names in the industry.

HVAC Buddy

PT charts for 70+ refrigerants including legacy and low-GWP blends. Free basic version with optional paid upgrade.

What a Solo HVAC Contractor Actually Needs

If you're a one-person operation or a two-person crew, you don't need enterprise software. Here's what actually matters:

The essentials — scheduling (know where to be and when), invoicing and payment collection (get paid on-site, look professional), quoting (send clean estimates from the field), customer records (remember who has what equipment and when you last serviced it), and basic accounting integration (keep your bookkeeper happy).

What you don't need — complex inventory management requiring a dedicated person to run it, marketing automation suites, advanced reporting dashboards, HR and payroll modules, multi-location dispatch optimization.

The honest reality: a feature-heavy system that's hard to adopt will slow you down more than it helps. Contractors end up adapting their processes to the software rather than the software adapting to them.

The best approach for small shops: pick one free tool that covers the essentials (scheduling + invoicing + customer management), add a free engineering app like Bluon or CoolCalc for the technical side, and stop paying for features you'll never use.