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Free HVAC contractor tools
Browser-based calculators and templates built specifically for 1–5 tech residential HVAC shops. Fast answers, professional output, and zero email gates. Built and maintained by the team behind Ratchly.
Quick answer
Ratchly offers three free HVAC tools for residential contractors: (1) a Manual J-style HVAC load calculator for cooling and heating BTU/hr sizing, (2) a printable HVAC invoice template with refrigerant and equipment fields, and (3) a fillable HVAC service agreement template for recurring maintenance plans. All run in the browser, all are free, and none require an account.
HVAC Load Calculator
Estimate cooling and heating BTU/hr for any home using climate zone, square footage, insulation, windows, and occupants. Recommended tonnage included.
HVAC Invoice Template
HVAC-specific invoice with fields generic templates skip: equipment make/model/serial, refrigerant type and pounds, labor and parts split, license number.
HVAC Service Agreement Template
Eight-clause maintenance plan contract: covered equipment, visit scope, member benefits, exclusions, payment, renewal, cancellation, signatures.
Why these tools exist
Most "free HVAC tools" online are email-gated lead magnets from enterprise software vendors targeting 50+ tech shops. The Ratchly free tools are built for the other 95% of the industry — the owner-operator and small-crew shops who need a fast calc, a clean invoice, or a real contract today, without giving up an email address or watching a sales demo.
When the tools aren't enough
Templates work until you have more than a handful of customers. Then renewals slip, invoices age past 30 days, and Sundays get eaten by admin. That's when Ratchly earns its keep — built for HVAC shops with 1–5 techs, no enterprise contract.