New Diagnostic Tool

Logs all checkpoints every 10 seconds and charts it — show the graph to another tech and get a real second opinion.

HVAC Tools & Calculators

Free HVAC tools and calculators for technicians and homeowners including Comfort Fix Finder, BTU, Dew Point, Superheat, and Subcooling.

For Licensed & Trained HVAC Technicians Only

This checklist is intended exclusively for use by licensed, certified, and trained HVAC professionals. It is not a DIY guide and should not be used by untrained individuals to perform repairs or diagnostics. The purpose of this checklist is to help qualified technicians maintain a consistent, step-by-step workflow so that no critical step is overlooked or skipped during service.

Room Airflow Balancer

Room Airflow Balancer

Interactive duct balancing simulator. See how much air each room gets, adjust trunk and branch dampers, and get suggested settings to move more air to the room you care about.

HVAC Brand Directory

Explore HVAC equipment brands, discover which parent company owns each one, and compare SEER2 ratings, warranties, and refrigerant types.

Dedicated Circuit Explainer

Dedicated Circuit Explainer

Interactive tool showing why HVAC equipment needs a dedicated electrical circuit. Toggle appliances on and off to see how shared circuits overload and trip breakers.

TrueZONE Wiring Visualizer

TrueZONE Wiring Visualizer

Interactive diagnostic tool for troubleshooting condenser issues in TrueZONE zone control systems. Step-by-step decision tree to isolate why a condenser won't shut off.

AC Installation Cost Estimator

AC Installation Cost Estimator

Get an instant cost estimate for central AC installation in the Bay Area. Includes equipment, labor, permits, HERS testing, and electrical circuit.

Mini Split Price Estimator

Mini Split Price Estimator

Get an instant all-in price estimate for mini split installation in the Bay Area. Includes equipment, labor, permits, HERS testing, and electrical circuit.

SEER2 Cost Calculator

Estimate your AC running costs from its SEER2 rating — choose your system size (2.5–6 tons) and SEER2 to see hourly, daily, and monthly operating costs.

Comfort Fix Finder

Comfort Fix Finder

Diagnose likely comfort issues by mapping home symptoms to airflow, return, duct, or sizing root causes.

What Actually Breaks on Your AC?

What Actually Breaks on Your AC?

An interactive breakdown of residential AC failures by category — wear, airflow, refrigerant, electrical, drainage — and how often each one actually breaks.

HVAC Field Checklists

Interactive step-by-step checklists for techs and homeowners — AC not cooling, seasonal tune-ups, compressor and coil replacement, mini split install, and furnace diagnostics.

BTU Calculator

BTU Calculator

Calculate the required BTU capacity for heating or cooling a room based on its size and insulation.

Psychrometric Chart

Psychrometric Chart

Interactive psychrometric chart with click-to-plot state points, all 7 air properties on hover, and process-line analysis (ΔT, ΔW, Δh, SHR) for AC coils, heaters, and humidifiers.

R-410A Pressure-Temperature Chart

R-410A Pressure-Temperature Chart

Interactive PT chart for R-410A. Tap the saturation curve, edit a temperature or pressure, scan the lookup table — every view stays in sync. Built for superheat and subcool field work.

R-22 Pressure-Temperature Chart

R-22 Pressure-Temperature Chart

Interactive PT chart for R-22. Click the saturation curve, edit a value, or scan the lookup table — every view stays in sync. Built for legacy R-22 service and reclaimed-stock work.

R-32 Pressure-Temperature Chart

R-32 Pressure-Temperature Chart

Interactive PT chart for R-32. Click the saturation curve, edit a value, or scan the lookup table — every view stays in sync. Built for modern A2L heat-pump and split-system service.

R-454B Pressure-Temperature Chart

R-454B Pressure-Temperature Chart

Interactive PT chart for R-454B. Click the saturation curve, edit a value, or scan the lookup table — every view stays in sync. Built for the lower-GWP successor to R-410A.

Dew Point Calculator

Dew Point Calculator

Determine the dew point temperature based on air temperature and relative humidity.

Superheat Calculator

Superheat Calculator

Calculate superheat to ensure your fixed orifice metering device is operating correctly.

Subcool Calculator

Subcool Calculator

Calculate subcool to verify proper refrigerant charge and system performance.

Operating Cost Calculator

Operating Cost Calculator

Estimate your HVAC operating costs based on system size, efficiency rating, and electricity rates.

Motor Winding Calculator

Motor Winding Calculator

Diagnose motor health with an interactive checklist and winding resistance analyzer for single-phase and three-phase motors.

Capacitor Tester & Calculator

Capacitor Tester & Calculator

Safely test capacitors with our interactive checklist, keep-or-replace analyzer, and parallel capacitor combiner.