Air Conditioning Quick Reference Guide

As A/C season approaches, it's essential to ensure systems run efficiently to prevent call-backs and maintain customer satisfaction. Here are key diagnostic and performance checks:

1. Airflow First

• 400 CFM per ton (e.g., 3 tons = 1200 CFM, 2 tons = 800 CFM).
• Check filters, open registers, zone dampers, and ESP levels.
• Adjust blower speeds carefully (higher speeds aren’t always better).

2. Superheat – Compressor Protection

• Formula: Line Temp – Gauge Temp (Line temp should always be higher).
• Baseline: 10°F (Use manufacturer charts for target values).

3. Gauge Temperature Readings

• Low Side (Blue Gauge): Indoor Coil Temp → Target: 40-45°F.
• High Side (Red Gauge): Outdoor Coil Temp → Target: 95-105°F.

4. Subcooling – Liquid Line Charge

• Formula: Gauge Temp – Line Temp (Gauge temp should always be higher).
• Baseline: 10°F (Use manufacturer charts for accuracy).

5. Low Ambient Charging Precaution

• Avoid charging below 65°F—charge by weight in cold conditions.

6. Inspect & Replace Worn Components

• Check capacitors, contactors, and line insulation for wear.

7. Run Cycle Best Practices

• Minimum 15-minute cycles to ensure proper dehumidification & equipment longevity.
• Short cycling reduces efficiency and may cause damage