Older Homes and Original Ductwork: What to Look For

Tacoma's older neighborhoods are full of houses that have outlived several furnaces. The heating equipment in the basement may be ten years old, but the metal ducts running across the ceiling could be original to the house, or close to it. That isn't automatically a problem. Well-built sheet-metal ductwork can last a very long time. But old ducts do have patterns, and knowing what to look for helps you decide what needs cleaning, what needs repair, and what can be left alone.

Start in the basement or crawlspace

If your home has a basement, the main trunk line is often visible: a large rectangular duct running down the middle of the house, with smaller round branches heading off to each room. In crawlspace homes, you'll need a flashlight and a safe way to look in from the access hatch.

Look for:

• Disconnected or sagging branches. A branch that has pulled loose from the trunk sends warm air into the crawlspace instead of the room above.
• Rust or water stains. These suggest moisture, either from a leak, condensation, or a damp crawlspace.
• Mixed materials. Old metal ducts joined to newer flexible duct is common after remodels. The joints are where dust and leaks tend to show up.
• Old wrap or tape. Some older homes have duct insulation, wrap or tape that may contain asbestos. Leave it alone and have it tested before anyone works on or near it.
• Signs of animals. Droppings, nesting material or chewed insulation near ducts mean pests have been there.

Damaged, disconnected or deteriorating ducts are a job for an HVAC contractor. Pests, mold or suspected asbestos should be handled by the right professional before any cleaning.

Read the registers

Registers tell you a lot about a system without opening anything up.

Floor registers are common in older homes. They catch everything that falls in, from dirt and pet hair to crayons and coins. Lift one out and look down the boot, the short section just below the grille.

Painted-over registers may have louvers stuck in one position. That can make rooms run hot or cold.

Very few returns is typical of many older systems. A single central return in a hallway or at the bottom of the stairs may serve the whole house, so it handles a lot of air and collects a lot of dust.

Dust streaks on the wall or ceiling around a register can point to dirty ducts or air leaking around the register boot.

Signs the ducts need cleaning

The EPA suggests considering duct cleaning when there's a clear reason, such as substantial visible dust and debris inside the ducts, debris being released into rooms from the supply registers, or vermin in the system. In an older home, you might notice:

• A thick, gray, felt-like layer inside the return when you remove the grille
• Dust puffing from registers when the furnace starts
• Debris visible in the bottom of floor register boots
• No record of the ducts ever being cleaned, combined with any of the above

If the ducts look clean inside and dust isn't coming out of the registers, you may not need a cleaning yet. Changing the filter on schedule might be all the system needs for now.

Ducts added after the house was built

Many older Tacoma homes were heated by other means before forced air arrived. When ducts were added later, installers worked with what the house allowed: runs through closets, chases between floors, and routes that bend more than a modern design would. Those bends and long horizontal stretches collect more dust. They can also make some rooms harder to heat evenly. Cleaning removes buildup but won't change the layout. If comfort is the problem, an HVAC contractor can tell you whether changes would help.

What a cleaning covers in an older home

American Air Duct Cleaning Of Tacoma cleans supply and return ducts and registers in homes across Tacoma and nearby communities. Basic air duct cleaning is $199 for up to 10 vents, plus $29 per additional vent. For one or two problem runs, such as a floor register that keeps filling with debris, deep duct cleaning focuses on individual vents at $59.99 per vent.

We don't repair ducts, handle asbestos, or treat mold, and we'll tell you if we see something that needs another trade first. Learn more about air duct cleaning or see the pricing page.