HVAC technician inspecting ductwork and equipment

HVAC Cleaning vs HVAC Replacement

Cleaning can work for light contamination. Replacement is often safer when insulation or components are saturated or degraded.

Quick Answer

If mold is limited to hard, cleanable surfaces and the moisture issue is fixed, professional HVAC cleaning can be enough. If contamination is widespread, the system has porous insulation, or components are water damaged, replacement is often the safer long term option.

See our guide on HVAC mold remediation for containment and cleanup steps.

When Cleaning Is Enough

Contamination is limited to metal or hard plastic surfaces
The moisture source is fixed and the system is dry
There is no mold in internal insulation or flexible duct liner
You can access and clean coils, drain pan, and blower housing

When Replacement Is Safer

Porous duct liner or fiberglass insulation is contaminated
Components were flooded or remain damp
Mold returns quickly after cleaning
The system is old or inefficient and due for replacement

Replacement may also be the right choice when contamination is extensive or when access makes thorough cleaning impossible.

Cost and Downtime

Typical Cleaning Scope

Source removal and HEPA vacuuming
Coil and drain pan cleaning
Duct cleaning where accessible
Filter replacement and system balancing

Typical Replacement Scope

Full system or duct replacement
New filters and sealed ductwork
Optional upgrades for filtration and humidity control

Get multiple bids and ensure the scope includes moisture source repair. Use our contractor vetting guide to compare bids fairly.

Verification Steps

Confirm the moisture source is repaired
Replace filters and document filter type and size
Inspect ducts and coils after cleaning
Consider clearance testing if remediation was extensive

For major projects, consider post remediation verification before reoccupying the space.

Decision Checklist

Get free access to the full guide

6 questions to decide cleaning or replacement