Field Guides
HVAC field guides for real service calls.
Practical HVAC troubleshooting guides, airflow diagnostics, duct sizing walkthroughs, and estimate strategies for technicians working in the field.
Field guides
Choose a guide for the call in front of you.
Find checks for cooling, heating, airflow, and duct-sizing questions.
AC not cooling but the fan is running?
If your AC is not cooling but the fan is running, this guide explains common causes and how HVAC technicians diagnose the issue.
02Why is my AC freezing up?
Learn why an AC freezes up, the most common causes, and how HVAC technicians diagnose airflow and refrigerant issues in the field.
03What should static pressure be in HVAC systems?
Learn what static pressure should be in HVAC systems, how to measure it, and what high readings mean for airflow and performance.
04How to measure airflow in HVAC systems
Learn how HVAC technicians measure airflow using static pressure, CFM targets, and field diagnostic tools.
05How to size ductwork correctly
Learn how to size ductwork correctly using airflow requirements, static pressure, friction rate, and practical HVAC design principles.
06How to estimate HVAC jobs in the field
Learn how to estimate HVAC jobs in the field, including labor, parts, diagnostics, airflow issues, and repair or replacement quote strategy.
07Why is my furnace blowing cold air?
Learn how HVAC technicians diagnose a furnace blowing cold air, including thermostat setup, ignition, airflow, limit trips, and temperature rise checks.
08How to troubleshoot low airflow in HVAC systems
Learn how HVAC technicians troubleshoot low airflow with filter checks, static pressure readings, blower data, duct inspection, and delivered-air verification.
09What causes high static pressure in HVAC systems?
Learn the common causes of high HVAC static pressure and how technicians isolate filter, coil, duct, return, supply, and blower setup problems.