Most folks don’t look forward to a test. Memories of being unprepared or questions over material you didn’t know would be included.. fortunately, passing a Duct Blast Test is nothing like taking a high school test.
Duct Blast Testing (made simple)
1. Seal the System
2. Pressurize the System
3. Measure the Pressure at various points
Comparing pressure at different points in a systems provides us with a “leakage ratio”. That “leakage ratio” helps us understand how much of the conditioned air we are creating is making it to the desired location. Even well-performing duct systems can experience leakage of up to almost 10%. That’s why in today’s modern home, where registers are often located far away from air terminals, it’s essential to verify that sealing work has been carried out effectively to maintain system efficiency.
Preparation is key to success in any project. By cleaning surfaces and removing oil, dust, dirt, rust and moisture before sealing, you create an environment for your sealants to do their job.
Here are a some of the materials today’s HVAC Contractors use when building an air-tight duct systems:
Liquid Sealers
Applied with a brush, these types of sealant have a thick syrupy, consistency. They can be applied to areas by brush or pumped into joints, shrinking considerably upon drying.
Mastics & Embedded Fabrics
Mastics applied to seams with a brush can help create an airtight duct system, with some products lasting up to 20 years. New woven fabric technologies have improved sealing capabilities.
Gaskets
Used around flanged joists to enhance efficiency, gaskets are available in various forms to suit installers preferences.
Tapes
A wide range of options, but may experience adhesion loss over time due to air pressure, flexure and drying. It’s crucial to ensure capability with substrates, especially non-metal flexible ducts to prevent potential failures.
Duct system locations can make visual quality control challenging for HVAC contractors, low crawl spaces, sealed off systems to drywall, construction is a problem-solving process. Duct Blast Testing provides General & HVAC Contractors with confirmation they have built a well-sealed duct system. Let your customers know that you test the work so they can enjoy peace of mind their HVAC is efficiently using energy!