As an HVAC expert, I have witnessed firsthand the importance of properly sealing air ducts. Not only does it ensure optimal performance of the system, but it also helps reduce utility costs. One of the most commonly used products for duct sealing is duct putty, which is widely considered to be the best solution by many professionals. Duct putty is a sticky material that does not harden, making it easy to work with.
It is also non-toxic and fire resistant, making it a safe choice for sealing ducts. This sealant is typically applied with a caulking gun or spatula and can last up to 20 years. However, in some cases, duct seals may fail after just a few years. There are several factors that can affect the lifespan of an air duct sealant.
These include the age of the air conditioning system, the climate in which the building is located, the efficiency of the appliances that rely on the system, how often filters are changed, and the maintenance of the rest of the system. The need for a duct sealant like putty arose due to the difficulty of sealing ducts from the outside, especially in hard-to-reach areas. To ensure proper sealing, it is recommended to start by sealing air leaks with putty or metal tape and insulating all accessible ducts, such as those in attics, mezzanines, unfinished basements, and garages. While duct putty can be used to seal coated sheet metal air conditioning ducts with concrete slabs under certain conditions, there are other options available for different types of installations.
For example, Aeroseal is a popular choice for residential applications and comes with a 10-year warranty. It has also been strength tested for 40 years. When it comes to sealing ducts, it's important to consider the performance of the sealant. In the case of duct putty, the UL mark is generally used to seal junction boxes, not for duct entrances that contain electrical or communication cables.
This is because the performance of a duct putty that has not yet cracked or sunk can be compromised due to shrinkage, causing cracks in the seal itself. The consequences of faulty duct seals can be costly. Not only can it lead to premature cable failure and damage to electrical appliances and telecommunications equipment, but it can also cause damage to carpets, floors, and even drywall. This is why it's crucial to choose a sealant that meets the performance parameters suitable for the installation.
Duct putty remains one of the most commonly used products for sealing electrical and telecommunications ducts around the world. Its versatility allows it to be easily worked by hand to form an infinite variety of shapes that can be pressed to seal HVAC ducts, hence its name as duct putty. In conclusion, while duct putty can last up to 20 years, its lifespan can be affected by various factors. To ensure optimal performance and avoid costly consequences, it's important to choose a sealant that meets the specific needs of your installation.
Whether it's duct putty or another product like Aeroseal or closed cell foams, proper sealing of air ducts is essential for any HVAC system.