If your energy bills increase dramatically over a short time, your air ductwork may no longer be functioning as it should. One of the main reasons to replace ductwork is if hot or cold central air is escaping through holes, cracks or deteriorating connections as it moves from the heating, ventilation and air conditioning (HVAC) unit through the ductwork. It also may be time to replace air ducts if there's an excess of dirt or dust inside your home, if your family or employees are experiencing heavier allergies than usual, if the building won't seem to stay warm or cold, if the temperatures are different in each room of the house, or if your HVAC unit is too noisy. Replacing faulty ductwork is a short-term investment that has long-term returns. You save money on utility bills, your building becomes more energy-efficient, you improve the air quality in your home or office, and you get more control over your home's temperature.
If you have central heating and/or air-conditioning in your home, the warm or cool air is delivered to each room through a system of connected ducts and vents. The air ducts for a central HVAC systems are typically located above a home in the attic or upper crawl space, or underneath a home in the space between the foundation and the floor, so you don't see them unless you have cause to replace them. If your home does not have an HVAC system and you plan to add one, you will need to have new ductwork installed.
The cost for air duct replacement by a professional technician will depend on the work required. If the pros need to get into the deep recesses of your building, your costs will be higher than if the ducts are easy to access. The material you select for your air ducts will affect cost, as will the size of the job. Your geographic location also affects the price, as the cost of labor and the cost to do business are higher in some areas than others. In many cases, the cost to install ductwork is based on the number of linear feet of ducting to be installed. Ductwork installation could cost $35-$55 per linear foot on average, including materials and labor. If you are ready to take back control of your air quality and home temperatures, here are the cost factors for air duct replacement.
Ed Mack of Air Duct Professionals in Lake Elsinore, California, creates estimates based on the number of ducts to be installed. Often pricing per duct run ranges between $150 and $250 from Air Duct Professionals. Mack explains that a typical single-family home may need 6-10 duct runs. Jim Hoover, owner of HVAC2U in Warrenton, Virginia, specializes in new construction, but can also install new ductwork or replace ductwork for customers in his area. He charges $5,000-$6,000 for a typical new construction ductwork installation job, which takes 2-3 days and usually requires all four of his crew members on-site. The hourly labor rate for his full crew is $250, but replacing failed ductwork may require only one or two installers at a total cost of $500-$600, including materials. Replacing multiple duct runs may cost more than $1,000 — possibly as much as $2,500.
The accessibility of a home's ductwork is a key factor in estimating the cost to replace it. Ductwork located in an attic crawl space may be difficult to get to and creates a hot and potentially hazardous environment for the crew. Installing ductwork in the crawl space beneath a home limits movement and poses a lighting challenge.
The type of materials you choose for ductwork will affect the cost as well. Flexible non-metallic ducting is the most affordable at $1-$2 per linear foot on average. Installers often prefer it because it bends and can more easily snake through attics and flooring. Flexible aluminum ducting is slightly more expensive and less prone to tearing. If you have had problems with holes or cracks in the past, this may be a good choice. Sheet metal, the strongest material, costs more than non-metallic or flexible aluminum ducting, with additional labor costs for multiple turns.
Signs you need new air ducts
Air ducts are a bit like your lungs. You generally don't think about them unless you start having a problem with them. Your air ducts will give you loud and clear signs when they need repair or replacement. Here are some signs that you need to replace your air ducts:
- The house or office is extra dusty. If you have holes or cracks in your air ducts, dust will be pulled into the ducts and be pushed out the vents into your rooms.
- Residents are sneezing frequently or experiencing more allergy symptoms than usual.
- Your energy bill is higher than usual.
- The heating system or air conditioner isn't changing the temperature of your home or office as you would expect. Cracked or damaged ducts allow cool or hot air to escape before it is pushed into the rooms of your home, meaning the temperatures won't change no matter what the thermostat reads.
- The temperature in each room is different, even though the thermostat is set the same throughout the house.
- Your HVAC unit has a shorter lifespan than expected. If there are holes or faulty ductwork, your HVAC unit has to work overtime to compensate. This can cause the unit to burn out too soon or operate poorly.
Mold in air ducts
Mold loves to colonize and spread wherever it can find moisture, and that includes the inside of your air ducts. Mold is a naturally occurring organism that isn't inherently harmful, but high concentrations of it inside your home can harm your health and even the integrity of your home's structure. If you live in a humid climate, you are more likely to experience mold in your HVAC ducts than those who live in dry climates. Cleaning mold out of your air ducts is not a standard part of duct maintenance, so this is not something you should expect to have done every year. In fact, the Environmental Protection Agency (EPA) states that you should only have your air ducts cleaned for mold if there is "substantial visible mold growth inside hard surface ducts." Be cautious of companies that report finding mold in your ducts and encourage you to purchase mold elimination services from them. If you believe mold could be in your air ducts, get a separate opinion from an independent party before contracting any additional work.
There are several ways to help prevent mold from creeping into your air ducts:
- Make sure your condensate drain pan (under your air conditioning unit) is not collecting sitting water. This flat pan catches the water underneath your unit as it heads to drain. If water pools over time, mold will quickly colonize and infiltrate your air ducts to be blown throughout each room of your house.
- Keep your HVAC air filter clean. When your air filter is clogged with dust and dirt, it can quickly migrate to the condensate drain pan and feed existing mold, especially if standing water accumulates in the drain pan.
- Keep your house clean of dust and debris overall. Dust and dirt can also nourish mold when they land on wet surfaces.
- Keep the air vents and returns in each room clear of any obstructions.
If you have leaks in your air ducts, you could be spending a fortune on keeping your home cool in summer and warm in winter. Damaged air ducts allow warmed or cooled air to seep out of cracks and holes, wasting energy and money. Replacing your air ducts may require an upfront investment, but it will help you save on utility bills in the long run, and have a positive impact on the environment and your home's energy efficiency forever. In addition to air duct replacement, you can save energy and money by following simple steps like turning down your water heater or installing an adjustable thermostat. Want more? Here are 15 tips to make your home more energy efficient.
How to hire air duct replacement pros
Finding an air duct replacement professional doesn't have to be hard, dirty work. Doing a small amount of research online and then asking a few questions before hiring should result in a positive experience and some fresh new air ducts. First off, read reviews of the pros. Work with a company that provides a positive customer experience. A negative review doesn't necessarily rule out a pro; look carefully at how the pro responds to unhappy customers. Verify that the company is operating legally. Many states require professionals who install new HVAC air ducts to have an HVAC contractors license; look for a contractors license number, and verify that the license is valid and up-to-date. States such as Alabama and California have online portals where you can verify an HVAC contractor's license and see if there are any complaints against the company. If you live in a state such as New Hampshire that does not require HVAC professionals to have a contractors license, be sure to research the company's reviews, reputation and background thoroughly before hiring.
Ask your potential HVAC company how long they have been in business (under their current business name). Fly-by-night companies often spring up quickly and disappear when problems occur; they usually lack a solid online presence and have little verifiable history such as customer reviews or community engagement. Even legitimate companies can misbehave. Research whether your state requires a permit to update or replace your HVAC system. For example, in California you are required to have a building permit for HVAC system updates, so confirm that your contractor is complying; you'll be the one whose home insurance could be cancelled if they fail to get proper permits. Find out whether they offer a warranty on their products and labor, and be sure to get all warranty agreements in writing.
Once you've determined the company is legitimate, discuss pricing. They may want to give a free, in-home estimate, or they may provide a quote over the phone. In either case, request their estimate in writing. Ask for a breakdown of labor, materials and miscellaneous costs (such as travel fees) so that you understand why the project costs what it does.
If a duct cleaning service informs you that your ductwork is damaged or needs to be replaced, ask for photos and get a second opinion from a qualified service provider. Older ductwork can still function properly if it is well-maintained.
- Read client reviews and follow up with references to make sure you're choosing the right pro for your project. For more, check out our tips for smart hiring.