Hydronic Condensate Drain Slope Calculator

Why Slope Matters

Condensate drains must be sloped properly to ensure gravity carries water away from the unit. A common rule is at least 1/8 inch per foot for pipes up to 2 inches in diameter.

Flow Rate Considerations

Each pipe size can only handle a certain maximum flow rate before water backs up. For example, a 3/4" pipe may only handle ~2 gph safely.

Common Issues

Clogged or undersized condensate drains can cause water overflow, leading to damaged equipment, leaks, and indoor air quality issues. Checking slope and flow can prevent these problems.

Condensate Drain Slope & Flow Rate Advisor

Condensate Drain Slope & Flow Rate Advisor

Why Slope Matters

Flow Rate Considerations

Common Issues