The key to comfort and great indoor air quality in your home, is a clean, well-functioning ductwork system.
If you experience temperature fluctuations, dusty air, odors, loud noises in the vents, etc, it may be time to take a closer look at your air ducts. Sometimes, the solution is as simple as cleaning them.
At other times, repairs or replacement of the whole duct system may be necessary.
To replace your old ductwork, contact your local HVAC pros for FREE ESTIMATES!
Cost To Replace Ductwork
On average, the cost of replacing ductwork is $15-27 per linear foot. A typical single-family home requires 30 to 90 linear feet of air ducts. However, the exact figure will depend on the layout of each particular house.
Linear footage pricing can be confusing for most homeowners. How do you know home many feet of ductwork you have or need? There is a simpler way to understand this.
Most homes need about 1 linear foot of ducts, for every 10 square feet of lining (conditioned) space. Sometimes you need more, and sometimes less. However, 1 ft per 10² ft average is a good place to start.
Keep in mind, that a contractor will charge you more for difficult access. In fact, this is the single factor that can significantly drive up your labor cost. The majority of homeowners report paying around $2,900-3,900 for a complete replacement or installation of new insulated ducts, in a 2000 sq. ft. home.
If you need to replace old vents, each one may cost $6-25, depending on material and design. Fancy, decorative vents can cost as much as $70-120
GET ACCURATE PRICING using our Air Ducts Cost calculator, which allows homeowners to choose different options that are unique to their home, including size, height, duct type, insulation, etc.
Upgrading Ductwork In An Old House
As much as 40% of your cooling capacity can be wasted in the ducts! Even if you have insulated ducts, your losses will be around 20-25%.
Think of it this way: if you spend $100/month on cooling, $20-40 of that is wasted in the ductwork!
While many older homes have a functioning ducts system in place, it may still require upgrades to accommodate central air installation, and/or to lower losses in the old ducts.
If a contractor will need to fix or modify existing ductwork, you can expect to spend an extra $1,000-3,000+.
The price difference will depend on the scope of work. Having properly functioning, clean ducts is essential if you want your AC unit to be energy efficient and work at maximum capacity.
Common modifications for existing ducts
– Insulate old ducts! Adding 6-10R insulation around ducts can cost about $7 per 1 foot of duct run, but can reduce your energy losses in the ducts by up-to 50% and your overall cooling energy cost by 20%.
That is an equivalent of upgrading from 13 SEER to 17 SEER AC, and the average saving can be as much as $300-500/season!
You will also see a significant reduction in your heating bill (if you use central air furnace.
– Increase the size of the furnace blower (rated in CFM – cubic feet per minute). An undersized blower will not be able to move the right amount of air through the house. Moreover, this can also lead to the coils freezing over.
– Seal the air ducts. Leaky ducts are one of the most common efficiency problems in an old home. Air leaks cause cool air drafts during the heating season and hot air drafts during the cooling season. They also increase your monthly spending on energy costs.
– Install larger supply registers to improve air flow. Most old, 1/4 inch grilles allow for a very limited flow of air. Putting in larger size grilles will boost air flow efficiency by 15-25%
Cost To Install Brand New HVAC Ductwork
For homeowners looking to install a new central air system, in a house that didn’t previously have one, the average cost is around $4,000-6,000, just for the air ducts.
In small homes, where the install is easy and straight forward its possible to pay as little as $3,000-3,500, however this is rare.
Installing them in a larger house, can cost as much as $7,000-10,000+. Oversized, complex configurations that need to be installed around trusses can run as high as $15,000-16,000.
Keep in mind that this is a very labor intensive project and can take 3-4 days to complete.
Factors That Increase Ductwork Installation Cost
The price range for new ductwork installation is very wide spread. The following factors will increase your total cost:
1. Location of the ductwork: typically new ducts are installed either in the basement or the attic. Depending on the condition and accessibility of the space, the HVAC contractor will determine the most efficient and economical placement.
2. Number of stories: if you have more than 1 storie in your home, you will require more ducts. This will significantly increase the cost of the project.
3. Number of vents: the more rooms you want air conditioned, the more vents an HVAC contractor will need to put in. Thus, the total cost will go up.
4. Number of temperature control zones: the more zones you want to have, the more expensive it will be to install central air.
5. Duct material: different duct materials cost differently; flexible wire coil ducts are most economical, while sheet metal ducts are most expensive. A contractor will determine which material will be most appropriate in your house.
6. Age of the house: typically contractors will put an upcharge on installing ductwork in a very old house, because they know that there will be unexpected complications along the way. The amount of the upcharge will depend on the discretion of the contractor.
Types Of Ducts
Overall, there are four duct types that can be installed (see chart below). They come in the following shapes: round, oval, spiral, rectangular.
Your pro will choose the shape that will be the best fit for the space you have.
Also, most homes are constructed in a way that requires using a combination of different types of ducting.
|Type||Price Per Linear Foot||Features|
|Vinyl Flex||$1 – 2||least expensive, quick and easy to install, ideal for|
|hard to access spaces, can be prone to tearing, lightweight|
|Aluminum Flex||$1.3 – 4||ideal for winding through challenging spaces, more|
|durable and less likely to tear than vinyl, includes|
|insulation and a vapor barrier, lightweight|
|Sheet Metal (galvanized steel or aluminum)||$1.5 – 6||most durable material, resistant to mold, ideal for|
|straight lines, hard to insulate. Some are available with|
|fiberglass lining that provides insulation, helps avoid|
|condensation issues, and serves as a sound barrier|
|Fiberboard (boards of compressed resin||$4.5 – 6||provides superior sound and thermal insulation, serves as a|
|bonded with glass fibers)||water and air barrier. Great for straight lines, where temperature|
|control is desirable, Easy to cut.|
Features Of A Properly Installed Ductwork System
Because air ducts are hidden, you as the homeowner, and even a home inspector will never be able to judge if the installation was done correctly. It is very easy for an unscrupulous contractor to skip on critical parts of the installation. Here they are:
1. Each TY junction needs to have custom fabricated manual dampers, to ensure balanced air flow. Without these, you will end up with some rooms that have too much air blowing, and other rooms, where there is not enough air flow.
2. Ducts need to be insulated at each TY junction. This is very important, as insulation will prevent future condensation and mold problems.
3. Every joint needs to be double sealed and crimped. This will prevent the ductwork from separating after a number of years. If this happens, the system’s efficiency will plummet, and you may not even feel like your house is being air conditioned at all.
While you may not be able to check if these were actually completed, you can ask pros bidding on your job, questions about these, and weed out people based on their answers. You can also include these as part of your formal, written contract.
It is important to note that these are standard procedures that need to completed to be compliant with building code. If they are not done, this is actually a violation of the code.
Air Duct Cleaning Costs
On average, homeowners across the US, report spending $300-500 to clean the air ducts in a 1,500 sq.ft. house.
In a larger house, pricing can range from $450-700. Typically, companies charge $30-35 per vent, or a flat fee that depends on the square footage of the house.
The process includes disinfecting the returns and filters in each vent, and then using high-pressure vacuums to remove dirt and debris from the ducts.
A thorough cleaning with proper equipment should take 3-4 hours, and sometimes longer, depending on the size of your house. If a company does the job in under 1 hour, you should assume that they didn’t do it well, and most likely you will need to hire someone else.
Pro Tip: since this is an unregulated business in most states, and no licensing is required, there are many scams going on. In particular, you should stay away from companies that offer rock bottom “deals” of $100 and under.
These low offers are just used to get their foot in the door. Then scare tactics are often employed to convince the homeowner that there are serious problems, such as mold.
The price all of a sudden becomes $600-700 or even more! Moreover, these unscrupulous contractors often don’t have the right equipment and actually make the problem worse, by damaging your ducts and releasing dust and other pollutants into the air.
Bottom line: you should only hire a reputable company, that has been in business for a while and has many great reviews.
Why Should You Clean Air Ducts?
Often, homeowners wonder if hiring professionals for this cleaning is a necessary form of maintenance, or just a waste of money?
The reality is that it all depends of the quality of the job and the type of ducts you have. As mentioned earlier, if they are properly cleaned with the right equipment, it may a good investment.
It may prolong the life of your central air system, improve energy efficiency, and prevent the build-up of dust and other allergens inside the home. HVAC pros recommend to do this once every 3-4 years.
However, one scenario when this is NOT recommended, is if you have plastic flex-ducts (a lot of homes have these). They actually get damaged from heavy-duty scraping and cleaning, and often end up needing to be replaced, after the job is done:(
The truth is that you can live without this professional service, if you replace your AC filters on a regular basis, about every 3-4 months. Moreover, if you use a high quality air filter in the first place, you can prevent the build up of dust and mold, so no cleaning will be required.
Cost of Ductwork Repair
If your ductwork is very old, there may be places where it becomes torn, or has holes that require patching up.
In case the areas are easily accessible, this repair can be completed very quickly, by simply sealing and patching the areas with an appropriate material.
Ductwork repairs can range from $350-700. Often, handy homeowners perform this on their own.
However, if the areas that require patching are numerous and are hard to reach, it may be best to replace the entire thing.
How To Figure Out If Your Air Ducts Are Leaking
Leaking ducts will also greatly effect the comfort of your home environment. In fact, this is how you would be able to tell if you have a problem with your ducts.
Think if you notice any the following:
- One or more rooms in your home is too warm or too cold
- Very high utility bills in the summer and winter months
- There is little or no air flow from registers in some rooms
- You change the air filter frequently because it gets dirty. If you need to change your filter about once a month, this means you have leaking return ducts.
- You notice streaks of dust at registers
- You discover a missing, crushed or broken air duct.
Once you call a contractor for an inspection, he will be able to tell you exactly what the problem is and suggest the best course of action. He will have special equipment to test for various issues, which are otherwise not detectable.
For example, a pro can preform a special blower test to measure the exact amount of air leakage that is escaping through the ducts. Other tools can help measure air pressure, as well as pin point the site of the air leak.
Once the ductwork is fixed, you will experience a dramatic difference in temperature comfort throughout your house, as well as better air quality.
If someone in your home has allergies or other respiratory issues, make sure that your ducts and filters are working properly. Otherwise, neglecting this may exacerbate their health conditions.
Repair vs. Replace Ductwork
If your ductwork is not functioning properly, it is important to determine whether you should repair or replace it.
A new system can be very costly, so you don’t need to jump on this option, if less expensive repairs can still do the trick.
Here, having a trusted contractor is critical, because some unscrupulous pros may tell you that replacement is the only option, because they know they will be making significantly more money.
Here are a few scenarios in which getting a new system is warranted:
1. Old age
Typically, a system can function properly for about 10-15 years. After this point, it will start to slowly deteriorate, although it may still work well for many more years. In some homes, they can be as old as 30-35 years.
However, if your system is not working well, and it is old, the best thing to do is replace it. This may be a more cost-efficient solution; if you spend money repairing a very old system, you will most likely need to pay again shortly to replace it. If you replace it right away, you will be saving time and money on the repair.
2. Poor quality materials
If you find out that the ducts or their insulation are made from cheap, low quality materials, it may be smart to simply install new ones.
You may end up spending a lot of money on constant repairs, while enduring discomfort in your home. At the end of the day, repairs will not fix anything long term, and eventually you will need to get another system.
If you have plastic air ducts that are covered in mold, you will most likely need to replace them, because cleaning will not work. However, it is possible to clean mold off of metal ducts.
Pro Tip: don’t let a contractor talk you into replacement, if you have metal ducts and mold and dirt are the only problem with the system.
Keep in mind that mold is a serious issue that should be taken care of right away, because it can lead to many respiratory issues if left in your air for a long time.
If someone in your house has any respiratory conditions such as asthma or allergies, their symptoms can be severely worse, if there is mold present.
4. Bad design
In some homes, the culprit of many issues with energy loss and uncomfortable temperature zones is simply poor design.
Designing an efficient system is not a “one size fit all solution”, and every house has its own specific needs.
Unfortunately, many contractors cut corners when it comes to this part of the job. This is why it is so important to work with an experienced pro, who has a proven track record of doing good work.
Depending on how flawed the design of your system is, it may be easier and more cost efficient to replace it with a more efficient system.
Why Its Very Important To Have Good Ductwork
It is essential to realize that when you install central air, it will only be as good as the ductwork. Even the most energy efficient unit will not function at maximum capacity, if you have leaking ducts.
With a poorly functioning duct system, you will lose 20-30% of cooled air into the attic or basement. This will inevitably increase your monthly cooling costs. Your AC system will also endure more wear and tear, because it will run more frequently.
This is why, many HVAC professionals find that quality central air installation also requires ductwork replacement, especially if its very old.
If you don’t have new ducts (under 5 years), ask your contractor to fix or replace anything that is old. Typically, leaking ducts can be sealed, but sometimes replacement is necessary.
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