https://hvacresource.us/blogs/field-notes/superheat-or-subcooling 2026-11-11T13:46:06+08:00 weekly https://cdn.shopify.com/s/files/1/0754/4347/0438/articles/field-notes-superheat-or-subcooling.jpg?v=1794375966 Superheat or Subcooling? How to Know Which One Sets the Charge HVAC technician reading a digital manifold gauge connected to an outdoor condenser https://hvacresource.us/blogs/field-notes/what-500-microns-really-tells-you 2026-11-11T13:46:07+08:00 weekly https://cdn.shopify.com/s/files/1/0754/4347/0438/articles/field-notes-what-500-microns-really-tells-you.jpg?v=1794375967 What 500 Microns Really Tells You About a Vacuum Vacuum pump connected to the service valves of a new outdoor heat pump https://hvacresource.us/blogs/field-notes/check-airflow-before-the-gauges 2026-11-11T13:46:09+08:00 weekly https://cdn.shopify.com/s/files/1/0754/4347/0438/articles/field-notes-check-airflow-before-the-gauges.jpg?v=1794375968 Check Airflow Before You Touch the Gauges Technician holding a dirty air filter beside an open furnace and air handler https://hvacresource.us/blogs/field-notes/no-cool-call-ten-minute-triage 2026-11-11T13:46:10+08:00 weekly https://cdn.shopify.com/s/files/1/0754/4347/0438/articles/field-notes-no-cool-call-ten-minute-triage.jpg?v=1794375969 No-Cool Call? A Ten-Minute Triage Before You Hook Up Technician testing outdoor condenser wiring with a multimeter https://hvacresource.us/blogs/field-notes/testing-a-run-capacitor 2026-11-11T13:46:11+08:00 weekly https://cdn.shopify.com/s/files/1/0754/4347/0438/articles/field-notes-testing-a-run-capacitor.jpg?v=1794375971 Testing a Run Capacitor the Right Way Technician testing a dual run capacitor in an outdoor condenser https://hvacresource.us/blogs/field-notes/r32-r454b-on-the-job 2026-11-11T13:46:55+08:00 weekly https://cdn.shopify.com/s/files/1/0754/4347/0438/articles/field-notes-r32-r454b-on-the-job.jpg?v=1794376015 R-32 and R-454B on the Job: What Actually Changes Technician beside a heat pump with a refrigerant cylinder and recovery machine https://hvacresource.us/blogs/field-notes/gas-furnace-ignition-sequence 2026-11-11T13:46:56+08:00 weekly https://cdn.shopify.com/s/files/1/0754/4347/0438/articles/field-notes-gas-furnace-ignition-sequence.jpg?v=1794376016 The Gas Furnace Ignition Sequence, One Step at a Time Technician testing a gas furnace with a combustion analyzer in a basement https://hvacresource.us/blogs/field-notes/recovery-cylinder-basics 2026-11-11T13:46:57+08:00 weekly https://cdn.shopify.com/s/files/1/0754/4347/0438/articles/field-notes-recovery-cylinder-basics.jpg?v=1794376017 Recovery Cylinders: Fill Limits, Colors and Safe Handling Gray and yellow recovery cylinder on a refrigerant scale next to a recovery machine https://hvacresource.us/blogs/field-notes/mini-split-flares-that-dont-leak 2026-11-11T13:46:58+08:00 weekly https://cdn.shopify.com/s/files/1/0754/4347/0438/articles/field-notes-mini-split-flares-that-dont-leak.jpg?v=1794376018 Mini Split Flares That Don't Leak Technician on a stepladder working on a wall-mounted ductless mini split https://hvacresource.us/blogs/field-notes/reading-a-pt-chart 2026-11-11T13:46:59+08:00 weekly https://cdn.shopify.com/s/files/1/0754/4347/0438/articles/field-notes-reading-a-pt-chart.jpg?v=1794376019 Reading a PT Chart Without Getting Fooled Manifold gauge set and tools on a workbench in an HVAC training workshop