During a recent remodeling project that involved adding new rooms, my outdated heating system became a problem. Our noisy, inefficient furnace was on its last legs, and the ducts were wrapped with asbestos. State law prevented air-conditioning contractors from modifying the system, so the time had come to remove the ductwork and replace the furnace.

Two air-conditioning contractors recommended the same asbestos abatement company, so that’s the one I called first. The company gave me a ballpark estimate over the phone, based on the number of registers in the house: one day at the daily minimum of $1,025.

I also called a couple of other companies under “Asbestos Removal” in the phone directory. Their prices were comparable, so I made an appointment for the first company’s estimator to come to the house.

The estimator checked the condition of the ducts and measured their lengths. He found a few separations and showed me where the asbestos was friable. Following his written confirmation of his phone estimate, we scheduled a removal date.

When the asbestos abatement contractors arrived, they first taped plastic sheeting over all the registers and sealed up cracks and openings in the floor (around the kitchen pipes, for example). Then they sealed the perimeter of the basement crawlspace where the ductwork was located.

Once the crawlspace was reasonably airtight, they connected a large, clear hose between a vent hole in the exterior wall and a sophisticated vacuum system. When this vacuum was switched on, it created a negative air space under the house that drew all ambient air out through special filters in the vacuum, cleaning the air and preventing tainted air from moving into the house.

They assembled three plastic-pipe frames, each the size of a small closet, and then encased them with polyethylene sheeting. These three chambers, when joined together and sealed at the crawlspace doorway, became a kind of “air lock” between the hazardous and safe areas. After removing the ductwork, they entered the first chamber to remove their coveralls and gear, hosed down in the center room, and dressed in the outer, clean room.

They took air samples from the hazardous area before, during, and after the work. These were taken to a lab, and the results were made available to us later. A trained inspector from the company inspected and approved the workmanship after the crawlspace was sealed off and after the ductwork was removed.

Before entering the area, the workers stepped into special, disposable coveralls that also enclosed their feet and included a hood. They wrapped duct tape at their ankles, collars, and heads to tighten the fit and pulled on disposable respirators. Under the house, they first sprayed a water mist to settle any dust. Then they sprayed the entire area with an “encapsulant” that converted the hazardous asbestos fibers into solid, safer form.

They disconnected the ductwork from the register boots and furnace, crushed them, and bagged them in large, double polybags. Ductwork running up into walls was left intact (because it was enclosed, it wasn’t a hazard), and they painted the boot stubs with a heavy, latex-based coating. When all removal was complete, they sprayed the entire area again with the encapsulant.

They tagged and coded the bagged hazardous waste and gave me a manifest listing the number of bags, to ensure proper disposal.

The next day they had the air-quality results (asbestos fiber count was below the required standard) and gave me permission to unseal the area. I was able to handle replacement myself with the help of a local furnace dealer that caters to do-it-yourselfers. I found that, since the advent of flexible ductwork, installing new ducts is quite easy. Carrier makes a high-efficiency forced-air system that is particularly easy to install because it doesn’t require roof venting. I just set it in place and had a plumber hook it up.

I may never know whether or not removing the ductwork was necessary. I do know, however, what peace of mind it gave me. Should I sell the house someday, the presence of asbestos won’t drag down the sale price, and I won’t have to worry about a potential hazard to the future homeowners. In the meantime, my family and I can enjoy efficient heating throughout the house and feel confident that the basement area is safe.