AssureStep
Installed-base follow-up for HVAC contractors

Static Pressure Calculator

Calculate total external static pressure (TESP)

Free tool with a path into installed-base follow-up

Why this tool matters

Solve the calculation or lookup now, then keep the answer attached to the installed base so it can support maintenance follow-up, warranty timing, equipment history, and replacement conversations later.

Next best step

Use the result in the field, then start a free AssureStep account when you want the context to stay visible after this visit.

How to measure: Use a manometer to measure supply and return plenum pressures with the system running.

Positive number (measure downstream of furnace/air handler)

Negative number (measure upstream of furnace/air handler)

Find on equipment nameplate (typical: 0.5" WC for residential)

Understanding Static Pressure

TESP (Total External Static Pressure) is the total resistance to airflow in your duct system.

Formula: TESP = Supply Pressure - Return Pressure (note: return is negative, so this adds the absolute values)

Target: Keep TESP below equipment rated pressure for optimal performance

High TESP causes: Reduced airflow, frozen coils, higher energy costs, equipment failure

TESP Guidelines

✓ Good (< 0.5" WC)

System operating efficiently within design specs

⚠ Marginal (0.5-0.8" WC)

Higher than ideal - check for restrictions

✗ High (> 0.8" WC)

Excessive - will cause airflow problems

✗ Critical (> 1.0" WC)

Equipment damage likely - immediate action needed

Track Static Pressure Over Time

AssureStep AssureStep gives you unlimited equipment tracking, revenue opportunity scanning, and A2L compliance monitoring when static pressure rises above safe levels before callbacks happen.

From tool to workflow

Free tools answer one question. AssureStep keeps the answer usable across the installed base.

Start free when you want maintenance follow-up, warranty timing, equipment history, and replacement opportunities to stay tied to the customer record instead of disappearing after the job.