Cleaning HVAC ducts after an M Streets fire

An original 1920s cottage had no ducts for central cooling. What is there today was fitted later, often with flexible duct in a low attic, in a crawlspace beneath the floor or both. These runs are often long, with tight bends around rafters and piers. Access can be awkward, which makes a thorough job slower. A contractor should map the system before starting, and you should ask to see that sketch or a set of photos. A rear addition may have a separate unit that serves only that part of the house.

If the fan was running during a fire, the return pulled smoke through the system and sent it to every room. Even with the fan off, smoke can reach duct openings through registers and leaky joints. A return grille in a hallway of a small cottage may sit only a few steps from the kitchen, so a stove fire can load the filter quickly. Keep the system off until someone has inspected it, since running it can spread residue to rooms that were otherwise clean.

Steep rooflines leave small attics, often with just enough room to crawl along the center. Smoke settles on rafters and insulation here as well as on ducts. Cleaning the ducts without dealing with the attic can leave a source of odor right next to them. Heat during a fire can also soften flexible duct or damage its jacket, so a run may be better replaced than cleaned. Summer attics in Dallas get extremely hot, so ask how the crew will work safely, and when.

Many original cottages sit on pier-and-beam foundations, with floor registers fed from below. Firefighting water can drain through floorboards and onto ducts, soaking their insulation or leaving water inside. Dallas clay soils hold moisture, so a wet crawlspace can stay humid for a long time, and wet duct insulation can grow mold ^[4]. Ask the crew to check for sagging or water-filled sections, and to deal with the crawlspace at the same time as the ducts.

Older heating systems may have insulation, tape or wrap that contains asbestos. It cannot be judged by eye, so suspect material should be tested before it is disturbed ^[3]. In a 1920s house that has been updated many times, old and new parts often sit together, including an abandoned floor furnace or old flue. Ask the crew how they will handle anything they are unsure about, and do not let anyone tear it out without testing first.

Many homes here have gas furnaces, and gas service comes from Atmos Energy. After a fire, it may be shut off at the meter, and only the utility or a qualified technician should turn it back on ^[5]. A furnace exposed to heat, smoke or water should be checked before use. If you smell gas, leave and call from outside.

Ducts are usually cleaned after the worst of the rooms have been cleaned, so dirty air does not get pulled back in, and before final odor treatment. Coordinate this with odor removal in the M Streets. Replace the filter again a short time after the system starts up, because leftover residue can collect there.

An older system may not be worth cleaning if the fire reached it. When the air handler took heat, the coil is badly soiled or flexible duct has melted, replacing part of the system may make better sense. Ask for photos and a plain explanation of why each part should stay or go. Your insurer may want to see the same evidence. If replacement is needed, mechanical work generally requires a city permit, and it can be a chance to rethink awkward runs through the attic.

Be careful with quick offers to clean everything in an hour. A real post-fire job in a house with tight attics and crawlspace runs takes time, because each section must be reached, cleaned and checked. Ask how the crew will reach the far ends of long runs, and how access openings will be sealed afterward.

Ask for the final photos to be sent to you and your adjuster.

Keeping the system off is hard during a Dallas summer. Attics and closed cottages get very hot, which can bring out smell and make the house unsafe for anyone sensitive to heat. Ask about a temporary stay elsewhere rather than running a dirty system. In winter, never use a fuel-burning heater indoors.

Ask the contractor for a likely restart date, and tell your household plainly before it starts to get hot or cold indoors.