· by Michael Blair, Nashville's Air Duct Cleaning
Duct cleaning is marketed hard and is genuinely useful in a defined set of circumstances. Being honest about which those are is more useful than either dismissing it or selling it on a schedule.
When it is justified
Visible mold growth inside the ducts or on other system components. Rodent or insect infestation. Ducts obstructed by substantial debris or construction dust. Ducts left open during a renovation.
Also after water intrusion into the ductwork, which in a Middle Tennessee crawl space is not unusual.
When it is not
On a fixed schedule with no symptom. In a system with clean filters, no visible dust at the registers and no odor, routine cleaning has little evidence behind it.
It also will not fix an allergy problem caused by humidity or by a poorly sealed filter, which is the more common cause here.
- Visible mold inside the ducts
- Rodent or insect infestation
- After renovation dust or an open system
- After water entering the ductwork
- Not simply because it has been a few years
What it will not fix
Duct leakage, which wastes far more energy than dust does. Poor filtration from a filter that does not seal in its track. Humidity, which in Middle Tennessee drives more indoor air quality problems than dust.
Sealing and insulating ducts in a crawl space returns considerably more than cleaning them.
Judging a quote
A very low advertised price with a per-vent structure is the pattern that leads to upselling on site. Ask what equipment is used and whether the main trunk lines are included.
Proper cleaning uses a high-powered vacuum with the system under negative pressure and agitation of each branch, not a shop vacuum at the register.