A run-around coil system links two coils with a pumped fluid loop (water or glycol). It recovers energy between airstreams that are too far apart for a direct plate or wheel.
Comparison
| Run-around coil | Plate | |
|---|---|---|
| Airstream distance | Any (loop spans building) | Must be adjacent |
| Effectiveness | 50-70% | 80-90% |
| Cross-contamination | None (separate coils) | None |
| Pump / power | Yes | No |
| Cost | Higher (loop + pump) | Lower |
When to use run-around
Use it when supply and exhaust are in different rooms or floors, or when total airstream separation is a code requirement. The fluid loop guarantees zero mixing.
When to use plate
Use a plate whenever the two streams are physically close; you get higher effectiveness with no pump or freeze-risk loop.