This is mostly true if the ductwork is situated in the attic, where the powerful summer heat can make your air conditioner work actively to cool your home.
When working with fiberglass insulation, always wear:
- Goggles
- Defensive clothing
- Accepted dust mask
Repairing Leaks in HVAC Ductwork
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Start by rotating your heating/cooling system on and feeling oblique the ducts for air leaks. Pay exact courtesy to any joints or connections in the ductwork, and scrape any air leaks you find. Then turn off the HVAC unit.
Repair a hole in HVAC ductwork using foil tape followed by duct gum. Shelter any air leaks with metal foil tape made for closing ductwork. Don’t use normal cloth duct tape on HVAC ductwork, since the epoxy resin won’t hold up to thrilling temperatures.
For an added layer of safety, you can apply duct gum to the tape and duct.
Protecting HVAC Ductwork
When HVAC insulating ductwork, use a balk, faced fiberglass lining with an R-6 or higher R-value. Use the type of metal foil duct tape suggested by the insulation producer to seal and hold the lining in place. Make sure the foil surface of the lining is free of earth before putting it on the tape. Peel the paper support off the tape as you apply it to avert the tape from stabbing itself.
If your current duct insulation is in honestly good condition, an extra layer of duct insulation can be smeared over it. If the old insulation is in a poor situation, remove it and substitute it with new insulation. Cut the lining to thickness and length, using a square and a sharp value knife, so that it fits cozily around the duct without squeezing the fiberglass. Apply numerous small pieces of tape through the insulation layer to hold it in place, then seal the whole length of the stratum in the insulation with a long strip of tape.
Where the segments of insulation join are organized, apply tape around the linkages by descending the tape under the duct, then flaking off the paper backing once it’s in position. Cautiously cut and fit the insulation together where the branch lines and registers come off the main trunk line, making sure there aren’t any gaps. Check that every seam and joint in the foil fronting on the HVAC ductwork insulation is wrapped securely with tape. This will avoid moist outside air from piercing the insulation and abbreviating on the ductwork.
HVAC Duct Insulation—Making Sound Selections
Generally, when the words duct insulation and audibility appear in the same sentence, I frequently think of duct liner and sound engagement. If I am having a more intellectual moment, I may think of supplement loss or friction loss. But that is not all there is to HVAC duct insulation. While duct liners surely play an imperative role in providing thermal and acoustical insulation for HVAC systems, duct casings or duct wraps also deliver significant replacements.
In its humblest form, duct lining (conventionally fiberglass), would be installed in four-sided ducts as part of an automatic procedure while the duct is being invented on a full coil line. This procedure has the lowest industrial costs, and you can make large quantities of ducts quickly. The cost and speed advantages may be reduced because every transitional piece (elbows, reducers, and rectangular to round) must be fabricated and insulated manually. The biggest disadvantage of lining ducts with a coil line is that there are very few insulation materials that can be applied on coil lines. This means specified design criteria—such as closed-cell or antimicrobial properties—may not be met with this partial selection. In these cases, the wanted insulation material must be practical by hand, which is very labor concentrated and increases the cost knowingly. Round and oval ducts constantly must be cloistered manually, which again, upsurges the trouble and cost of insulating the duct.
There is also the issue of double-wall duct building for round or rectangular ducts. The double-wall duct has the advantage of dividing (solid inner layer) or semi-isolating (perforated inner liner) the duct liner from the air stream, which is wanted for several reasons (e.g., protecting particulates out of the air stream and caring the liner from harsh environments). However, double-wall duct production and field installation have their own sets of difficulties, such as added initial cost, added weight, and a more difficult installation. Moreover, a solid inner layer means that no sound fascination is taking place.
Choosing HVAC Duct Insulation Materials
There are many deliberations when agreeing on materials, and lining a duct is more difficult than packaging a duct. Eliminating liner from the breeze addresses the IAQ worries and makes duct cleaning calmer. It also removes the need for double-wall ducts and decreases the quantity of sheet metal since the actual area of the duct is amplified. On the other hand, design changes to the air-handling system are needed to control annoying noise. Lower airspeeds bend in the ductwork, and mechanical sound attenuators can achieve noise control in unlined ducts. But, attenuators are an additional cost and take up extra space. Additionally, energy code necessities and control of getaway noise have not been met.
A wide diversity of materials can be used for duct shawls for both the HVAC insulation and jacketing. As duct wrap is connected on-site, there are fewer anxieties about insulation harm during shipping, on-site storage, and installation (problems that can crop up with lined ducts). Repair of duct wrap is cooler and less troublesome than repair of duct liner. Duct wrap takes up outside duct space, so deliberation must be given to provide passable clearance for installation as well as room to work. Contingent upon the scheduling, duct wrap can be vulnerable to damage from other trades.
Duct wrap can take the form of rigid or supple lining materials, and the selection procedure should be based on a variability of conditions: round, oval, or rectangular ducts; indoor or outdoor installation; lagging R-value only or breakout noise control only, or both; and type of ability (e.g., office, inhabited, retail, school, hospital/medical building, clean room, food and drink, or pharmaceutical production environment.) There are materials obtainable to meet all of these needs.
Just like the duct wrap resources, there is a wide variation of jacketing options to meet scheme necessities. There are the “traditional”: metal jacketing, PVC and mastic, and mesh. For some submissions, the newer ASJ or FSK jackets may be passable. Then, there is a variation of peel-and-stick type materials obtainable from numerous manufacturers. There are insulation resources obtainable in sheet and roll form with pre-applied jacketing, which decrease field installation time (and cost) while letting for installation over a wider diversity of environmental conditions. The latter are energetic thoughts since field insulation installation costs are characteristically higher than liner costs and installers often have little switch over the working conditions, which can vary importantly by geography and season, nonetheless of whether the installation is taking place indoors or outdoors.
