What Is the 20 Rule for HVAC?
Your AC can usually cool your home about 15 to 20 degrees below the outdoor temperature.
If it is 95°F outside, your AC may realistically cool your home to around 75°F–80°F.
The 20 rule for HVAC is a general cooling guideline. It does not mean your AC is broken if it cannot reach extremely low temperatures during intense heat.
❄️ Better Comfort
A properly working system should cool consistently and remove humidity.
🔥 Extreme Heat
Very hot days can make your system run longer than usual.
💵 Efficiency Matters
Dirty filters, low refrigerant, or poor airflow can increase energy costs.
Common Reasons Your AC Struggles
- Dirty air filter
- Low refrigerant
- Leaky ducts
- Dirty outdoor coils
- Poor attic insulation
- Old or undersized AC unit
AC Not Keeping Up?
If your AC is blowing warm air, leaking, freezing, or not cooling properly, HVAC Loyalty can help.
