ESP, Duct, and Access Checker

Short ducts may pass at 12 Pa.

Longer duct routes usually need a higher ESP check.

Access panels below 450 mm make coil cleaning harder.

Drain slope below 1 percent raises leak risk.

Flex connector length should stay near the Koven reference band.

Ceiling depth under 300 mm needs drawing review.

Return grilles placed too close to the fan can raise perceived noise.

Elbow radius and transition angle should be checked before order release.

Service crews need room to reach the valve, drain pan, and filter.

Procurement should send site photos when the ceiling void is tight.

Engineers should compare duct pressure with the chosen fan speed.

Owners should not accept a hidden unit without a service route.

Field drawings help.

Before release, mark any room where a beam, sprinkler pipe, cable tray, or lighting trough blocks the straight duct path, because those small conflicts often decide whether 30 Pa is enough or 50 Pa needs review.

Quiet rooms need extra care during return-air planning.