Questions to ask
- Was the system running during or after the incident, and does that change what you will check?
- Will you inspect inside the return plenum, the blower and the coil, not just the filter?
- Can you show photos of what you see inside the ducts?
- Will you use negative air pressure so dust is pulled out rather than pushed into rooms?
- How will you handle flexible duct, which is hard to clean?
- What do you recommend before the system runs again, and why?
What a thorough assessment covers
Air enters through return grilles, passes the filter, blower and coil, and leaves through supply ducts. CS powder tends to collect on the return side and the blower; capsaicin oil coats the blower wheel and coil fins. A thorough assessment looks at each of those, plus registers and grilles in affected rooms.
A good provider will tell you when full duct cleaning is not needed, for example when the system was off throughout and residue was limited to one room.
Reading the recommendation
- IfThe system ran while tear gas was in the houseExpect cleaning of the blower, coil and at least the return ducts.
- IfThe system was off and residue was limitedA filter change and register cleaning may be enough; ask for the reasoning.
- IfFlexible duct is coated with oily residueReplacement is often more reliable than cleaning.
- IfThe proposal is whole-house duct cleaning with no inspection photosAsk to see what they found before agreeing.
What to expect afterward
After an assessment, ask for a short written summary: what was inspected, what was found, what was cleaned or replaced, and any parts that could not be reached. Keep it with your other records. Before the system runs normally again, have someone run the fan with windows open while healthy adults move through the house and note any irritation.
If symptoms return when the heat or air comes on, the system likely still holds residue and the provider should come back.
Common questions
Will a better filter solve it?
A filter catches some particles in the air but not residue already on the blower and in the ducts.
Does a heat pump or mini-split need the same attention?
Yes. Indoor heads have coils and blowers that collect residue and should be cleaned per the manufacturer.
How soon can the system run again?
Once the filter is replaced and any recommended cleaning is done. Run it first with windows open and adults present.
General information for Berkeley, not a quote or professional advice. In an emergency, call 911.