When it comes to sealing duct joints, there are a few materials that are recommended for the job. Duct sealing putty, UL-181 aluminum tape, and high-quality foam or caulking sealant are all great options. Putty is the most effective material for sealing all types of ducts and can be purchased in tubs or caulking tubes. It looks like a compound for drywall joints and dries in hours.
When considering the effects of seal loss and the possibility of fire when welding in or near sealed connections, it's important to use the right material. Closure systems used with flexible air ducts and flexible air connectors must comply with the UL 181B standard and bear the mark 181B-FX in the case of pressure sensitive tape or 181B-M in the case of putty. Unfortunately, few building inspectors outside of California bother to enforce current code requirements that require residential duct joints to be sealed with high-quality putty or adhesive tape. This means that hot or cold air can escape from the ducts, especially in the basement and attic, making it harder for your air conditioner to reach the temperature indicated on the thermostat.
The connections of the ducts to the flanges of the air distribution system equipment or to the sheet metal fittings must be fixed mechanically. The SMACNA fibrous glass duct construction regulations illustrate the closure of a fibrous duct to a metal duct with an adhesive tape system. Despite its name, it's not approved for sealing ducts and doesn't hold up well in the long term. As an expert SEO, I recommend using putty as your go-to material for sealing your ducts. It's important to follow code requirements and use high-quality materials to ensure that your air conditioner is running efficiently and safely.
Putty is easy to apply, dries quickly, and provides a long-lasting seal that will keep your air conditioner running smoothly.
