What’s Good About Flexible Ductwork?
- Flexible ductwork is cheaper than metal ductwork. By the time you add insulation onto the cost of metal ductwork, you are almost double the cost of flexible ductwork that comes preinsulated (buy the R8 insulated ductwork verses the R6).
- Flexible ductwork is faster to install than metal ductwork. ...
What is the difference between rigid and flexible ductwork?
Flex duct or rigid duct can both fail as a duct system if improperly connected or sized incorrectly. Because flex duct is spiraled inside it is more restrictive to airflow. Therefore cfm sizing between flexible duct work and rigid pipe is not the same. Flex duct can be easily damaged both during and after installation.
How do I remove metal ductwork from my ductwork?
Unscrew any sheet-metal screws connecting metal duct to a boot or another section of duct. Pull the duct from the boots and set it aside to either be thrown away or recycled.
Should metal ducts be exposed or rigid?
Appearance is crucial to a good job and metal duct should be used when exposed. Example, crawl spaces use flex duct and garages use rigid duct. There is just a right place for flex duct and the same goes for rigid or sheet metal duct. Together they can make a really good air distribution system.
Should I change from metal to flexible HVAC ducts?
It originates at your air handler or furnace and ends at wall, floor or ceiling vents. Metal duct can still be found in many older homes, but flexible duct is more prevalent in newer homes. Both work well. Still, should you decide to change from metal to flexible duct, don't waste money on an HVAC contractor.
Are metal ducts better than flex ducts?
If flexible ductwork is installed correctly, the airflow will be the same or better than a metal ductwork. It's all in the installation. The advantage of metal ductwork is that you are taking less of a chance of the ductwork being installed wrong than with flexible ductwork.
Can I replace metal duct with flexible?
Metal duct can still be found in many older homes, but flexible duct is more prevalent in newer homes. Both work well. Still, should you decide to change from metal to flexible duct, don't waste money on an HVAC contractor. It's a time-consuming job, but definitely one you can do yourself.
Should you replace old metal ductwork?
“If your ductwork is over 15 years old, you probably should replace it. Ductwork has a maximum lifespan of 20-25 years. By 15 years, however, it begins to deteriorate, significantly reducing your HVAC system's efficiency, so replacement is the prudent option.”
What is the disadvantage of flex duct?
Cons of Flexible Ductwork Flexible ductwork can restrict airflow more than metal ducts. Greater airflow means better HVAC system efficiency, but flexible ducts are more susceptible to interference from compression, pinching, and twisting.
What type of ductwork is best?
Flexible ductwork is the best type of ductwork to use in tight or awkward spaces where rigid ductwork would be too difficult to install. Because these air ducts are flexible, they can bend around fixed structures to work in almost any space.
Does Flex duct reduce airflow?
Since flex duct, by definition, is flexible, it often flexes in ways we don't want it to. The result is poor airflow and ineffective HVAC systems.
How long do flexible ducts last?
10 to 25 yearsWhat is the functional lifespan of a flexible duct system? A search of industry articles, blogs, and chat rooms indicates it lasts from 10 to 25 years. Most flexible duct manufacturers warranty their products for about 10 years.
How often should you replace your ducts?
between 10 and 15 yearsThe ductwork in most homes lasts between 10 and 15 years before problems arise. If your ducts are more than 15 years old, have them replaced before major issues such as pests, gaps, or even collapsed sections of ducts appear.
When should you consider replacing the ductwork in your home?
about 10-15 yearsDucts are designed to last for about 10-15 years on average. They are made from a combination of materials such as fiberglass and plastic. At some point, these ducts will get damaged. The sooner you see signs of damage and do something about it, the better.
Is rigid ducting better than flexible?
The rigid material is also more difficult to carry and place in the right position. As a result, metal ductwork installation is a lot pricier. Flexible ducts are best suited for branching off the main plenum of your HVAC system. They run throughout the building and carry air to individual ceiling vents.
What is the most commonly used ductwork in an HVAC residential system?
Made of galvanized steel or aluminum, rigid sheet metal is the most common type of ductwork.
Should flexible ductwork be insulated?
When flexible ducts are located outside the conditioned space, they should be sealed to prevent loss of conditioned air and also insulated to prevent thermal loss or gain from the ambient air. All ducts, whether rigid or flexible, should be sealed with UL-181–rated duct mastic.
Can you use flexible duct for HVAC?
Flexible ducts are best suited for branching off the main plenum of your HVAC system. They run throughout the building and carry air to individual ceiling vents.
How do you attach a flex duct to a metal duct?
0:422:33Installing Flexible Duct - Insulated Duct - DIY - YouTubeYouTubeStart of suggested clipEnd of suggested clipFirst thing you do is take either air duct sealing or mastic. And spread it around the take offMoreFirst thing you do is take either air duct sealing or mastic. And spread it around the take off mastic. Comes in a bucket air duct sealing comes in a tube they're basically the same thing spread.
How do you connect a flex duct to a metal duct?
0:514:17How To Attach Flex Duct to Boot or Galvanized Round Pipe - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo now we'll take some duct tape. And this is about two inches wide. And just put it halfway on toMoreSo now we'll take some duct tape. And this is about two inches wide. And just put it halfway on to the Flex duct and halfway on to the bare metal. Other thing you're taping. And work your way around.
Can I use flexible duct?
Flex duct can be used in an attic. In fact, flex duct is one of the most commonly used ducting in attics. This type of ducting material is used so frequently in attics because it is far easier to install than rigid ducts, and it is likely to take up less space in this area of a house.
Why is the lack of information on "which duct product is best" justified?
The lack of information on "which duct product is best" is justified because the short answer is: "it depends."
Why do we seal ductwork?
The primary reason for the focus on sealing duct work is energy loss. The EPA Energy Star program estimates that as much as 20% of the air moving through a duct system is lost due to leaks, holes, or improper installation.
What is the rib on a flexible duct?
The ribs on the inside of a flexible duct reduce the air flowing through it measured in cubic feet per minute (cfm) causing back pressure to the source. There are mathematical calculations required to properly size flexible ducts for use in a residential home.
Should I keep ductwork clean?
Having seen the results from a duct blaster on many different configurations of residential duct work, I would recommend keeping the metal duct work and cleaning it.
Can you use mastic to seal ductwork?
If your budget allows, you may want to consider resealing your duct work with a mastic product. More than likely, the ducts are currently sealed with tape. Mastic is a superior sealant to tape and I've had severe difficulty in some cases passing the Energy Star duct air leakage test without mastic (i.e., using tape).
Why do you need flexible ductwork?
Flexible ductwork must be installed properly to get the right amount of airflow to each room and a poor installation can severely affect airflow and comfort in your home. This means no kinks, using 90 degree elbows at all ceiling cans and the ductwork is pulled tight with minimal slack to minimize friction resistance.
When did HVAC stop using metal ducts?
HVAC contractors have stopped using metal ductwork as their default duct material since the 1980s. The default ducts you’ll see in homes now is flexible ductwork, but that doesn’t mean that it’s a better for airflow.
How much compression is needed to convert a rigid duct to a flexible duct?
Converting round rigid metal ductwork to flexible ductwork all depends on how the flexible ductwork is installed. A 4% compression is a generally accepted practice. To get less than 1% compression would risk the duct being pulled so tight it would disconnect from one end. At a 4% compression, you loose about 1”-2” of duct diameter going from flexible ductwork to round rigid ductwork. That is, a 6” fleixble duct will deliver the same amount of airflow as a 5” KD pipe duct.
What is the best ductwork?
What’s Good About Flexible Ductwork? 1 Flexible ductwork is cheaper than metal ductwork. By the time you add insulation onto the cost of metal ductwork, you are almost double the cost of flexible ductwork that comes preinsulated (buy the R8 insulated ductwork verses the R6). 2 Flexible ductwork is faster to install than metal ductwork. Even with the additional time installing 90 degree elbows, trimming the ducts to the correct length, properly sealing and running the ductwork most efficienctly, it is less man-hours and costly than securing 3-10 foot lengths of sheet metal ductwork, securing them together, sealing the metal joints and finally wrapping everything in insulation.
Why is ductwork outlawed?
This type of ductwork has since been outlawed as it deteriorates and becomes so brittle it will crack and split open with the air pressure. When changing your air filters, if you see a clear inner liner at the return duct, you know you have this type of ductwork.
What is a rectangular duct?
The rectangular sheet metal ducts are nailed into the framing of the house and impossible to take out without removing the ceiling as well. Homes built in the 1970s-80s have this ductwork type delivering the conditioned air from a central heating and cooling system but also from an evaporative cooler.
What is the second type of ductwork?
The second type of metal ductwork is round rigid metal ductwork. Round metal ductwork can either be spiral duct, which comes in one 10’ section of different sizes and is not insulated. This is a great look for restaurants, commercial buildings or even homes that want an industrial look.
How to wrap flex ducts?
Slip a clamp over the end of the flex duct. Slide at least 1 inch of the core past the beads at the end of the air handler or vent boot. Wrap the end of the core twice with metal tape.
How to connect two ducts together?
Push the clamp over the core and boot and tighten it with a screwdriver or power drill. Roll the insulation and jacket back over the core to complete the connection. Follow the same procedure to splice two ducts together, except you'll clamp the ducts onto the ends of a metal-connector sleeve, instead of a boot.
Where does duct work in a home?
By Robert C. Young. Duct carries heated and cooled air throughout your home. It originates at your air handler or furnace and ends at wall, floor or ceiling vents. Metal duct can still be found in many older homes, but flexible duct is more prevalent in newer homes. Both work well.
What to wear when working with fiberglass insulation?
Wear gloves, goggles and protective clothing when working with fiberglass insulation.
What is the difference between metal and flexible ductwork?
A key difference between flexible and metal ductwork is that flex duct is notoriously easier to install. It’s lightweight and can bend however is necessary in order to adapt to the heating or cooling system. Installation goes much faster, reducing the cost of labor and downtime for your business.
Why is metal ducting better than other types of ductwork?
Durability is the number one reason why metal ducts make a better long-term investment. Though expensive, metal ductwork requires very little maintenance and withstands extreme outdoor temperatures. For this reason, sheet metal is the best material for lowering energy costs.
What is metal duct?
Metal ducts are constructed with rigid sheet metal, making them suitable for the main pillar of a trunk-and-branch ductwork layout. They’re directly connected to furnaces and supply air to the various flexible branches.
What is flexible duct?
Flexible ducts are best suited for branching off the main plenum of your HVAC system. They run throughout the building and carry air to individual ceiling vents. Flex ducts are available in a variety of materials that conform to the building’s shape as necessary, like rubber, stainless steel, silicone and polyurethane.
What are the downsides of flexible ductwork?
Air resistance. One downside to flexible ductwork is that the material creates more resistance to air flow. Unlike metal ducts, flexible ones often crumple in ways that make it more difficult for supply air to reach its designated ceiling vent.
Is metal ductwork a lot pricier?
The rigid material is also more difficult to carry and place in the right position. As a result, metal ductwork installation is a lot pricier.
Is it true that ductwork is out of sight?
The saying “out of sight, out of mind” couldn’t be truer when it comes to a building’s ductwork system. It’s easy to forget about air ducts when they’re hidden behind walls and in the basement. However, homeowners and business owners in St. George, UT must familiarize themselves with the difference between flexible and metal ductwork so they know which is best for their property.
Is metal ductwork better than flex ducts?
Flex ducts are better for existing trunk-and-branch heating and cooling systems. This is because they’re more versatile and flexible. Metal ducts are more rigid due to the nature of steel, making them ideal to build an entire HVAC system.
Can you replace metal duct with flexible?
Metal duct can still be found in many older homes, but flexible duct is more prevalent in newer homes. Both work well. Still, should you decide to change from metal to flexible duct, don’t waste money on an HVAC contractor. It’s a time-consuming job, but definitely one you can do yourself.
What is the disadvantage of flex duct?
The downside of flex ducting is that it is considered temporary with an acknowledged lifespan of only about 15 years. Another major disadvantage is that they are a little too flexible, so they are often incorrectly installed. And with greater friction than metal ducts, proper sizing is critical.
Are metal ducts bad?
The drawbacks of metal ductwork is that it rusts and it leaks. With new homes the rust isn’t much of a concern however with homes that likewise had a swamp cooler installed with metal ductwork, there’s a high chance of rusting currently taking place in the metal ductwork.
What is the best material for ductwork?
The best flexible air filter duct for commercial buildings in extreme climates are made from silicone, PVC, rubber, and stainless steel. They have an inbuilt resistance to heat and cooling that guarantees long-lasting productivity. Rubber and polyurethane are the best at abrasive resistance.
How long do flex ducts last?
What is the functional lifespan of a flexible duct system? A search of industry articles, blogs, and chat rooms indicates it lasts from 10 to 25 years. Most flexible duct manufacturers warranty their products for about 10 years.
Is replacing ductwork worth it?
Yes, and Here’s Why. Ductwork is a vital component of your home’s comfort, air quality, and energy consumption. You should replace old ductwork as soon as possible to maintain the performance of your HVAC.
Why is Flex duct so flexible?
Because flex duct is so flexible it has to be hung properly and sometimes more consistently than rigid pipe. Making sure that bends are made wide and open not sharp bends that will unknowingly kink and reduce air flow.
Why hang flexible ducting?
It’s very easy while hanging flexible ducting to choke off the air flow and increase the inefficiency of a high efficiency gas furnace or heat pump system.
What type of duct do crawl spaces use?
Example, crawl spaces use flex duct and garages use rigid duct. There is just a right place for flex duct and the same goes for rigid or sheet metal duct. Together they can make a really good air distribution system.
How much insulation is needed for flexible ducting?
Flexible ducting is available with one inch of insulation or with no insulation at all. Most codes for residential applications require 2 inches. You should check with your local building department. It’s very important when choosing to use flex duct that you have a really good filter system.
Why is Flex Duct so inviting?
The flex duct is such an inviting attraction because of the warmth radiated in the winter. No type of flex duct can withstand the desire of these animals to find comfort and enter the system. The critters obtain access to the entire duct system. It becomes to say the least, a disaster.
What are gores on a metal fitting?
Metal fittings such as boots, wye branches and elbows have gores and joints that either swivel or just connect pieces. Each of these gores or joints is an air leak and has to be sealed.
What is the best practice for installing ductwork?
The best practices and principles behind installing any type of duct work is correct sizing and the straightest line between two points.
