Condensate Drain Sizing Calculator
Size condensate drain lines for HVAC equipment per UPC/IMC requirements
Equipment Capacity
Drain Configuration
Drain Requirements
Minimum Drain Size
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Recommended Size
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Condensate Flow Rate
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Daily Volume
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Total Fall
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Trap Required
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Note: All condensate drains require proper slope and trap where connected to sanitary drainage.
Code Requirements (UPC/IMC)
| Equipment Capacity | Min Drain Size |
|---|---|
| Up to 20 tons | 3/4" |
| 21-40 tons | 1" |
| 41-90 tons | 1-1/4" |
| 91-125 tons | 1-1/2" |
| 126-250 tons | 2" |
Installation Notes
- Maintain minimum 1/8" per foot slope
- Provide trap if connected to sanitary drain
- Air gap required for indirect waste
- Auxiliary drain pan required for attic installations
- Consider condensate pump for negative slope situations
Condensate Production Rates
| Equipment | Typical Production | Peak Production | Notes |
|---|---|---|---|
| AC (per ton) | 0.5-1 gal/hr | 1.5 gal/hr | Varies with humidity |
| 90%+ Furnace | 0.5-1 gal/hr | 1.2 gal/hr | Acidic condensate |
| Condensing Boiler | 1-3 gal/hr | 5 gal/hr | Requires neutralizer |
| Dehumidifier | 2-8 gal/day | 12 gal/day | 70 pint unit |