HVAC IQ Pro

HVAC Tech Blog

Expert guides, diagnostic tools, and industry insights for HVAC professionals. Interactive calculators included.

All Diagnostics (2) Equipment (1) Fundamentals (2)
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Diagnostics 2026-04-21 ๐Ÿ“– 12 min read

How to Calculate Superheat and Subcooling โ€” The Complete HVAC Guide

Master the two most critical measurements in HVAC diagnostics. This guide breaks down the math, the meaning, and what the numbers tell you about system health โ€” with a free interactive calculator.

superheat subcooling refrigerant R-410A charging
Diagnostics 2026-04-21 ๐Ÿ“– 10 min read

TXV Troubleshooting โ€” Stuck Open vs Stuck Closed Symptoms & Diagnosis

The TXV is one of the most misdiagnosed components in HVAC. This guide covers the three failure modes โ€” stuck open, stuck closed, and hunting โ€” with the exact pressure readings and symptoms you'll see in the field.

TXV expansion valve troubleshooting refrigerant cooling
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Fundamentals 2026-04-21 ๐Ÿ“– 10 min read

HVAC Ductwork Sizing Basics โ€” Is Your System Starving for Air?

The best HVAC system in the world can't overcome bad ductwork. This guide covers the fundamentals of duct sizing โ€” how much air you need, how to know if you're getting it, and what happens when you're not.

ductwork airflow Manual D CFM static pressure
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Fundamentals 2026-04-21 ๐Ÿ“– 8 min read

What is Delta T in HVAC and Why It Matters for AC Performance

Delta T is the temperature difference between your supply and return air โ€” the simplest indicator of whether your HVAC system is actually doing its job. Here's what your numbers mean and what to do when they're wrong.

delta T temperature split airflow diagnostics cooling
Equipment 2026-04-21 ๐Ÿ“– 9 min read

How to Test an AC Capacitor โ€” Signs It's Failing Before It Dies

A failing capacitor is one of the most common HVAC service calls โ€” and one of the most preventable. Learn the signs of degradation, how to test properly, and why catching it early saves compressors.

capacitor testing multimeter compressor motor

Monitor Your HVAC Systems in Real-Time

HVAC IQ Pro continuously monitors superheat, delta T, amp draw, and more โ€” catching problems before they become failures.

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