Insulation isn’t only about keeping heat in. In the average home, around 20% to 30% of the heated or cooled air flowing through the ducts is lost to leaks and uninsulated surfaces, according to the Department of Energy. Generally called a duct blower door test, the technician seals the air intake and outlet registers before blowing air through the system. 7. Kevin O’Connor meets with paint experts. If necessary, switch the wires to reduce the blower to its lowest speed. Duct liner isn’t generally a DIY installation, and if your ducts already have liner, you don’t need to insulate the exterior. Designed for use on rectangular, circular and flat oval ductwork, Kooltherm Duct Insulation can be used to insulate ductwork installed both indoors and outdoors, in building services and HVAC applications. Please enter your email address. R-value is the measure of the ability of the insulation to prevent heat from either penetrating or escaping the object insulated. You may also want to know the measurements to accurately calculate the amount of airflow moving through the duct. Apply a long strip of foil tape along the seam in the insulation. No particular HVAC skill or experience necessary, $100 to $300, depending on size and complexity of the ductwork, Tankless Water Heaters: What You Need to Know Before You Buy. Wear rubber gloves to limit skin contact. Zillow, Inc. has a real estate brokerage license in multiple states. Even then, different areas of the home may require greater or lesser insulating power. When evaluating any type of duct insulation, make note of the installation method, the drawbacks and the advantages, as well as the insulation power, known as the R-value. Having your ducts tested adds to your expense, of course, with most professional inspections running $100 to $200. Also look for energy efficiency credits that may be available through the utility company or the state or federal government for testing and insulating your ducts. Duct and fittings have interconnecting ends that lock together with brackets. …insulating ductwork can be a great way to offset energy price increases from SMUD. 5. Some companies may offer the “after” test for free. To find a professional to perform the work, try your local utility company, HVAC service company or specialized testing companies. Seal the duct-to-register connection as well. Duct board, much like the duct liner, is also a fiberglass product. The higher the R-value (literally meaning resistance value), the better the insulation works. I would like to insulate this rectangular duct before I close it in. Also, local building codes are gradually beginning to require that new houses have a whole-house and duct blower door test performed. The second mistake is even more common: DIYers often do not understand that they must seal the ducts first. Follow the product instructions for precise application instructions. Friction is the enemy of airflow. Measure and cut your duct insulation a little large to allow overlap at every seam, both lengthwise and on the ends. strip of foil, and secure it with aluminum tape (Photo 2). These are the bulky, gray box-shaped ducts so common everywhere. To insulate your ductwork using wrap-style, foil-faced fiberglass insulation: Measure your ductwork. It’s also a good selling point if you ever put your house on the market. You don’t have to wash them, but wiping them with a damp cloth or whisking them with a broom and making sure the surface is dry will help the sealant-to-duct bond. Holes, leaks and gaps closer to the HVAC unit encounter higher air pressure than those farther away, so your greatest savings and increase in efficiency will come from sealing well at and near the unit. If you decide to proceed without testing your ducts, perform a thorough examination, looking for any rust, holes, severely damaged pieces, loose connections or missing portions, starting at the furnace and air unit and working back to the very last register in the home. Spread duct mastic or sealant across the duct seams, joints and very small holes. Insulate the Ducts With Liners. You’re throwing money out the window. I see no reason why using 1-inch insulating board should not work. When selecting your duct insulation, use the R-value you require to determine what product — or combination of products — you need. Start with clean, dry ducts. Stop wasting money and energy with a leaking duct system. You need insulation – even around your ducts – no matter where you live. Avoid compressing the insulation. First, some don’t realize that you can’t use paper-backed fiberglass insulation. In the end, it’s probably best to buy the blanket insulation. Get the latest This Old House news, trusted tips, tricks, and DIY Smarts projects from our experts–straight to your inbox. When it comes to adding duct insulation, your monthly savings in utility bills will soon cover the costs, especially if you install the insulation yourself. Zillow Group is committed to ensuring digital accessibility for individuals with disabilities. Use more than one layer if a single layer won’t give you the value you desire. Sealing the ducts prior to wrapping them with insulation reduces air escape, ensuring the cool or warm air gets where it needs to. Also … 1. Invest in duct insulation … 4.6 out of 5 stars 148. Steps: 1. That’s not a problem with one of these compact, ultra-efficient units that heat water as you need it. To install preformed duct insulation, start by disconnecting an elbow to expose the end of the duct. Here’s what you need to know about choosing, installing, and living with a tankless water heater. In this video, This Old House plumbing and heating expert Richard Trethewey helps a homeowner insulate his ductwork. This allows you to prioritize your sealing efforts, ensuring the most important areas are covered. Dia x 5 ft. L R-8 Ductwork Insulation Sleeve (6) Model# F8DS4 $ 12 23. If necessary, switch the wires to reduce the blower to its lowest... 2. Fibrous glass duct wrap insulations are manufactured to comply with ASTM C 1290, Flexible Fibrous Glass Blanket Insulation USed to Externally Insulate HVAC Ducts. A good place to start is by insulating your ducts. Remove a 2-in. Master Flow 8 in. Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct. Most heating and cooling ducts are metal. Gently pull the insulation over the entire length of duct. Before beginning, read the product instructions and follow wherever they deviate from general duct insulation guidelines: Measure and cut your duct insulation a little large to allow overlap at every seam, both lengthwise and on the ends. 2. You will receive a link and will create a new password via email. Still, spending the money will end up paying off in the end. 3. Cutting fabric-covered, heat-proof foam to fit the interior of your ducts is a low-cost, simple way to get the insulation and sound reduction you want. The type of insulation that is used depends on the size and shape of your duct, your budget, and your application. Copyright © 2020 This Old House Ventures, LLC. Here's how an inventive redo made an 1830s artifact just right for a 21st-century household. Measure and cut your insulation so there is a small overlap. Have questions about buying, selling or renting during COVID-19? Never use anything not specifically intended for use with HVAC ductwork. Unlike rigid ducts, which are cut to length … To install sleeves, you must either disassemble the ductwork and slide it on before reassembling the ducts or — as many homeowners find themselves doing — slit it and wrap it around like the blanket-style material. This equates to the perimeter of the rectangle to rectangle hopper plus eight thicknesses of insulation. UniTherm Ceramic Fiber Insulation Blanket R-Value: 2.27 (6# Density, 2300°F) (1 in. Wrapping the duct in a foil-faced blanket; or; Applying spray foam insulation to the outside of the duct. 6 Wrap each piece of insulation around the duct, then tape it in place using your metal duct tape. How to Cut Batts of Fiberglass Insulation. Who doesn’t want to save money on utility bills? Internally-lined rectangular ducts are fabricated with an outer metal shell and an insulation media glued and mechanically fastened to the interior surface. Do what you’re comfortable with — if you feel confident about doing the sealing yourself, it will be messy. To be precise, consult the Department of Energy’s Duct Insulation R-value Chart. Most insulation relies upon the air space between its fibers to deliver the R-value promised. 99. Check the speed of the blower motor on the furnace. Start Saving Money Today. We are continuously working to improve the accessibility of our web experience for everyone, and we welcome feedback and accommodation requests. Sheet Metal Connectors, Inc. double wall rectangular duct is a dependable, erosion resistant alternative to lined rectangular duct, providing improved protection for insulation exposed to the airstream. Will insulate the rest in the attic to prevent cold air dumping down into the kitchen in winter. To insulate the exterior, you have a choice between sleeve-style insulation and blanket wraps, which literally wrap around the ductwork. For larger square or rectangular duct I add the four sides up then add 6. You can fasten and secure the ends of the batts with duct tape, but that may cause the insulation to get spoiled. 3. $35.99 $ 35. An even, generous layer helps ensure your duct will never leak again. 9. Sometimes metal ducts are lined with duct liner, a 1-inch-thick fiberglass board that insulates the interior of the duct, rather than the exterior. Noise Reducer Hose - HG POWER 5inch PVC Silencer Hose Duct Flexible Ducting Hose Noise Reducer Hose for Inline Duct Fan (4ft) Talk to others about what works for them and shop around before choosing any insulation for any part of your home. You may have occasion to measure the size of the ductwork. When overlapped 2 to 3 inches and secured with tape, each joint should be very secure and leak-free. Check the speed of the blower motor on the furnace. Install insulation with the foil side out. Failing to perform this basic step will undermine your insulating efforts. For round pipe, "I" multiply the duct x 4 and add 4. If you need help deciding which type of insulation you need, set up an energy consultation. Wrap the insulation around the duct, allowing the beginning edge to ride up slightly over the previous piece. My vented attic in Virginia has a straight 28ft of 12" x 8" rigid rectangular trunk duct with seven 6" branches. Since they are generally used for short runs, when working on the remainder of your ductwork, check any flex ducts as well. This is perfect size for my 6" duct which I am installing for the kitchen range hood. With the aid of specialized tools, the technician can determine the amount of air leaking from your ductwork and where it’s occurring. So duct loss matters no matter what. Mark McCullough explains cobblestone aprons. In general, only use the tape by itself when you have no other choice. Tired of running out of hot water? Cut the insulation to width and length, using a square and a sharp utility knife, so that it fits snugly around the duct without compressing the fiberglass. Tom Silva and Jeff Sweenor install a drop finial and a swinging window. With age, house settling, rust from moisture, animal intrusion and a variety of other hazards, your ducts may obtain anything from pinholes to gaping voids, loose and leaking connections between pieces, or even potentially missing ducts. Some ducts, depending on the material and the location, are more vulnerable than others when it comes to air loss, but any duct has the potential to leak. Measure the circumference of the duct, add 2 in. Common problem areas include around the registers and vents, where they enter the room they service, and at each duct joint (connection). Keep in mind that it is better to over-seal than to have a remaining leak. strip of fiberglass to create an overlapping flap for taping (Photo 1). Repeat to insulate the remaining ducts. Work from the furnace or air unit back to the last (farthest) register in the home. Often used in tight spaces, such as in walls and ceilings, rectangular duct allows you to select larger sizes without increasing duct height. If you want to insulate your duct, measure it to cut the insulation to the right size. First, consider the duct location. It also keeps the heat out of the home (or duct). It also keeps ducts dry. 3. After the inspection, seal your ducts, keeping a few tips in mind: After the sealant is dry, the final step is insulating the ducts. to the total, and cut the insulation to that length. Perhaps the most commonly used insulation for joists and walls, the fiberglass itself is fine, but it doesn’t take much to get the paper hot enough to burn. Choose a tape to use with the sealant when necessary. As a rule of thumb, expect to install a minimum of R-5 material. Lost your password? Tape cracks or holes larger than 1/8-inch diameter with the tape selected. Apply mastic in a layer about as thick as a nickel. Ductwork insulation prevents this problem—and it saves you money in energy costs. Once you determine that your duct needs insulation, consider the type of insulation you want. x … Therefore, mechanical fasteners are more advisable for usage than duct tape. Ensure the material is turned the proper way; the vapor barrier should face out, and the fiberglass or other material should be against the duct. Special foil tapes work well, or select a mastic tape. I am starting a basement project and want to insulate the existing rectangular duct that runs down the center of the basement (photo attached). Brokerage, By searching Northstar MLS listings you agree to the Northstar MLS End User License Agreement, How to Carve the Best Pumpkin on the Block, Regain Your Garage: Simple Tricks for Getting Organized. The insulation is quite low around R-4, and also has many tears and rips, and the ducts need to be air sealed. Mastic is the most common sealant, but specially formulated duct sealant, in cans or caulk tubes, is also available. FREE Shipping by Amazon. Fiberglass duct insulation is available in various thicknesses. Get it as soon as Fri, Jan 15. However, if the ducts have a lot of leaks, the air that makes it to your rooms will not be as warm or as cool as intended. There is flexible duct wrap as well as rigid insulation board. Unfortunately, so many houses — especially newer homes — end up with ductwork running through the attic. 4. The process is simple if you use a wrap-style insulation product. To finish the job, butt the insulation edges together along the bottom of the duct, overlap the 2-in. Wrap the insulation around the duct, and then pinch the seam closed. Wear some protective clothing, a dust mask and goggles. Any tape tends to degrade or peel away with age, while mastic hardens to a stiff, durable surface. Once the ducts start rusting, you face having to install new ducts. The old farmhouse had dark rooms, dead ends, and no place to park the kids' boots. The result is higher utility bills, wear and tear on the heating and cooling system, and difficulty maintaining the temperature inside your home. Before beginning, read the product instructions and follow wherever they deviate from general duct insulation guidelines: Once your ducts are sealed and insulated, you can have a technician retest your ductwork if you desire. Cut the insulation with the utility knife in sections 2 inches larger than the circumference of the duct. This has the added benefit of keeping ducts free of mold. A list of our real estate licenses is available here.TREC: Information about brokerage services, Consumer protection noticeCalifornia DRE #1522444Contact Zillow Inc. Select your desired sealant, or use a combination of products as appropriate. Only a professional has the equipment and knowledge required, so it’s really not a DIY-friendly task. If, on the other hand, your ducts run across the ceiling of a heated basement or inside well-insulated walls and ceilings, your need for duct insulation is minimal. I would like to replace the insulation with R-8. Another product, known as flex duct, is a round framework of wires coated with fiberglass and encased in either foil or plastic to resist moisture and air leakage. As new and innovative products arise continually, these are by no means the only types of duct insulation available, nor will they remain the main types. At any point that you make any upgrade involving your ducts that requires a building permit, you will have to follow the current code. Although flexible ducts don’t require further insulation, they are vulnerable to damage, especially punctures. Before installing insulation check the ductwork for gaps or cracks. No matter how well you install the insulation or how high the R-value, even with the moisture/air barrier attached to the exterior of the insulation, it won’t prevent air and temperature loss if your ducts aren’t structurally sound. Use foil-faced insulation batts to wrap up the pipes but see to it that the whole thing is properly covered and any previous layers are thoroughly overlapped. Insulation isn’t free, but as the old saying goes, sometimes you have to spend some to make some. How does this apply to you? 6. These products are easily cut and fitted to achieve a neat, thermally effective insulation blanket over the exteriors of rectangular, round, oval, or irregularly shaped ducts. Additionally, uninsulated ducts can accumulate condensation, which eventually leads to rust. Use a stiff-bristled paintbrush or your fingers to spread the sealant. Snap a plastic cap onto the duct end, then slip the preformed insulation over the duct. Made from 1- to 2-inch-thick sheets of rigid glass fiber and coated with an aluminum laminate for a moisture/air barrier, duct board comes in sections that fit together like metal ducts. After reinsulating all ducts to R8, I plan to bury them in blown cellulose insulation, based on the report Compact Buried Ducts in aHot-Humid Climate House. All rights reserved. The crew reinforces floor joists. Leaks also tend to be common close to the blower fan and where the ductwork emerges from the furnace.