Frequently Asked Questions - Commercial



·   Q: Why Should Ducts in Commercial Buildings Be Sealed?
A: Duct air balance and thermal distribution (comfort and ventilation), help comply with building codes and reduces cross contamination between different zones in the building (i.e., smoking vs. non-smoking, bio-aerosols, localized indoor air pollutants).

·   Q: How Much Energy Does the Sealing Process Save?
A: Energy savings are different for light commercial vs. large commercial buildings and obviously depend upon the initial duct leakage level. The Aeroseal Energy Savings Excel spreadsheet can be used to estimate the savings for both types of buildings. For ducts above an insulated ceiling in a light commercial building, energy savings should be 10–30% of HVAC energy use, and peak electricity-demand reduction is generally a higher percentage. In a large commercial office building with a VAV system, energy savings and demand reduction should be 20–40% of fan-system energy use and 5–10% of cooling energy use. As a rough estimate, excluding any of the non-energy benefits of duct sealing, simple payback times typically range from 1 to 4 years, and return on investment between 30% and 70%.

·   Q: How Do I Know if the Ducts in My Building Need to be Sealed?
A: The existence of duct leaks in your building can be uncovered several ways. One way is to examine Test and Balance reports, comparing the total flow through the grilles with the total flow through the air handler, or by looking for systematically low flows at grilles that are far from the fan. Another way is to test a sample of duct sections for leakage, a test that Aeroseal technicians perform on a regular basis.

·   Q: How Does the Aeroseal Process Work?
A: The Aeroseal process seals duct leaks from the inside, using small sealant particles that deposit at the leaks without coating the interior of the duct system. This is accomplished by pressurizing the duct system with a fog of sealant particles sized to stay suspended in the air until they try to exit the duct system. By blocking all of the intentional openings in the duct system (i.e., diffusers or grilles), all of the sealant-laden air is forced out through to the leaks. As the duct pressure causes the particles to accelerate through the leaks, they stick to the edge and build upon each other until the leaks are sealed. By constantly monitoring the duct pressure and flow, the process-control computer calculates and the displays the remaining leakage in real time. When the sealing is finished, a complete minute-by-minute record of the process is printed, stored on the local computer, and then uploaded over the internet for archival on the Aeroseal server.

·   Q: Who is Aeroseal?
A: Aeroseal is a fully owned subsidiary of JMD Corporation that holds an exclusive license from the University of California for the aerosol-based duct sealing process patented by Lawrence Berkeley National Laboratory.

·   Q: Is the Sealant Material Safe?
A: The sealant material consists of a water-based solution (65% water) prior to application. The dried sealant material primarily contains two chemicals, vinyl acetate polymer (VAP) and 2-ethyl-1 hexanol (2E1H). The vast majority of what is left in the duct system is VAP, which has been used in water-based paints, adhesives, and hair spray. VAP has been used in chewing gum, and has no OSHA Exposure Limit. 2E1H is a common industrial solvent and is not considered toxic by OSHA. A review of the literature showed no ill effects after long-term exposure to concentrations of 200 ppm. The largest concentration of 2E1H measured in test houses was 1 ppb (200,000 times smaller), during Aeroseal injection. The sealant is UL-listed for smoke generation and flame spread (UL 723 0,0), and additional testing by UL showed no signs of mold growth or erosion.

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    Q: How Long Will the Seals Last?
A: Scientists at Lawrence Berkeley National Laboratory tested the performance of Aeroseal seals for 4 years under accelerated conditions, and were never able to observe a failure. This corresponds to 100,000 cycles under more severe temperatures and pressures than are found in duct systems. Aeroseal and the sealant manufacturer warrantee that seals will last at least 3 years in commercial application.

·   Q: How Large of a Leak Can be Sealed?
A: Aeroseal recommends sealing the leaks up to 5/8 inches across. Leaks more than one inch across can be sealed, however the sealing rate varies with the size of the leak times itself. In other words, the sealing time for a 1" leak is 64 times longer than that for a leak 1/8" across. Practically speaking, leaks larger than about 5/8" across are better suited to be sealed manually if possible.

·   Q: What Types of Ducts Can be Sealed?
A: Aeroseal is capable of sealing all types of ductwork, however the sealing rate varies with the type of ductwork. Sheetmetal ductwork seals most quickly, and internally lined ductwork seals most slowly. In certain instances, Aeroseal does not recommend sealing duct systems that are internally lined over most of their length, as the long injection times make the process very slow, and create excessive deposition of sealant material on the internal surfaces of the lining.

·   Q: What About VAV Boxes and Fire/Smoke Dampers?
A: Aeroseal generally avoids blowing sealant materiel through VAV boxes or fire/smoke dampers, however laboratory and field testing have shown that under the right circumstances this can be done without adverse consequences. Under no circumstances can sealant material be blown through VAV boxes with reheat coils. Should it be more practical to blow sealant through VAV boxes or fire/smoke dampers, it is recommended to consult with the engineers at Aeroseal LLC.

·   sealing in commercial buildings cost-effectively saves energy, improves

Frequently Asked Questions -Residential



·       Q: What size of holes can be sealed using the Aeroseal air duct sealing process?
A: Holes and cracks up to 5/8th of an inch wide can be completely sealed.

·       Q: What does the Air Duct Diagnostic and Inspection tell me?
A: Inspection discovers any obvious break in the duct work and, as the initial step of the sealing process, the Aeroseal system will establish an exact amount of leakage in the duct system. Of course, many people already know that a room or two in their house doesn’t get good air circulation because they can feel it. Or, they already know that their energy bill is high because they see it. The diagnostic measurement, provides a scientifically valid means to understand the performance of your air duct system. Many people are surprised to learn that homes typically leak 30% to 40% or more of their air through air duct leaks.

·       Q: What are the estimated savings? 
A: A series of government reports have shown that air duct sealing can lead to up to $850 in energy savings per year. Some homeowners have saved up to 40% on their energy bill. Naturally, exact savings are difficult to precisely estimate since they depend on a multitude of variables such as your weather, house condition and design, your heating and air conditioning system, system usage – as well as other factors like energy prices.

·       Also, all Aeroseal air duct certified technicians are qualified to run a program made by the Environmental Protection Agency (EPA) called “Duct Investor”. Duct Investor takes a comprehensive list of variables and provides a homeowner with the best available estimate of what they should realize in cost savings.

·       Q: In a nutshell, how does an Aeroseal air duct seal work?
A: Basically:

o   Preseal test to measure the leakage as a baseline for measuring progress.

o   Block off the registers with foam or plastic.

o   Inject an UL tested and approved aerosol into the duct system.

o   Since the air has no place to go except out through the leaks (the registers are blocked), the sealant material is deposited precisely at the air duct holes or cracks where leakage occurs.

o   A computer and sensors are used to measure and control the progress. The technology is patented from the University of California and the process is endorsed by the Environmental Protection Agency.

o   Postseal test to measure improvements.

o   Complete report and certificate printed on the spot to provide a record of improvements.

·       Q: Does the air duct sealing material become brittle?
A: The vinyl sealing material remains rubbery, never cracking.

·       Q: How long will the air duct sealing material last?
A: The sealing material has been found in rigorous testing to last over 10 years without failure.

·       Q: Do air ducts need to be cleaned before air duct sealing?
A: It's likely that the holes and cracks in the ductwork have allowed dust and other particulate matter to enter the system. If you are experiencing extensive levels of household dust, this might be the reason. In most instances, duct cleaning is not found to be required prior to Aeroseal sealing. Your Aeroseal contractor can advise whether it will be necessary to clean your ductwork prior to sealing.

·       Q: Does the sealant coat the inside of the ductwork?
A: The sealant only sticks to the holes in the air duct without coating the rest of the duct.

·       Q: Is the sealing material used by the Aeroseal air duct sealing system safe?
A: The sealant material consists of a water-based solution (65% water) prior to application. The dried sealant material primarily contains two chemicals, vinyl acetate polymer (VAP) and 2-ethyl-1 hexanol (2E1H). The vast majority of what is left in the duct system is VAP, which has been used in water-based paints, adhesives, and hair spray. VAP has been used in chewing gum, and has no OSHA Exposure Limit. 2E1H is a common industrial solvent and is not considered toxic by OSHA. A review of the literature showed no ill effects after long-term exposure to concentrations of 200 ppm. The largest concentration of 2E1H measured in test houses was 1 ppb (200,000 times smaller), during Aeroseal injection. The sealant is UL-listed for smoke generation and flame spread (UL 723 0,0), and additional testing by UL showed no signs of mold growth or erosion.

·       Q: Does the sealant leave an odor?
A: The Aeroseal air duct sealing process leaves no lingering odor, and since the material does not put off gas over time, there will be no odor for the life of the product.

·       Q: If the rooms of my home have inconsistent temperatures, can Aeroseal improve the performance of my heating and A/C system(s)?
A: The Aeroseal sealing system can help improve the comfort of your home by reducing the difference in temperature levels throughout your home.

·       Q: Can the Aeroseal air duct sealing system help reduce my utility bills?
A: Some homeowners have saved up to 40% of their energy bills after having the Aeroseal air duct sealing system seal their central air duct system. A typical homeowner should expect to see measurable reduction in energy use for Heating and Cooling.

·       Q: Can the Aeroseal air duct sealing system reduce the noise made by the return and supply grilles in my home?
A: This noise is usually the result of two conditions. One is created when the ductwork is undersized and air is rushing through your air duct system. The other condition is caused when a limited amount of air is allowed to flow through the indoor coil of your heating and cooling system. Once the exact problem has been identified, your contractor can provide the best solution for noise reduction.

·       Q: Can the Aeroseal air duct sealing system reduce the amount of dust in my home?
A: Ductwork runs through attics, crawlspaces, basements, garages, and walls. Leaking return air ducts pull in dust and other indoor air pollutants and sends them to the central heating and cooling system. From there they sent to the living areas of your home. The Aeroseal air duct sealing system can reduce the amount of leakage by as much as 90%, reducing dust and other indoor air pollutants from the conditioned air in your home.

·       Q: Is the sealing guaranteed or can I get my money back? What if it doesn't work? 
A: Aeroseal provides a 10-year warranty on the seals created with our process. We have enormous confidence in the quality of our seals since they are based on Lawrence Berkeley National Laboratory research and a patent through the University of California. The EPA has endorsed Aeroseal, as have numerous local energy utilities. Note: the warranty is for on-site seal failures and does not cover additional damage (e.g. an electrician that steps on a duct while running wiring), wear or tear (i.e. the shelf life of a plastic duct is passed, rodents eat into a duct, or a duct rusts out), and subsequent replacement of failed ducting. Overall, in the 75000 plus seals done to date, we have received negligible number of warranty claims.

How Does the Aeroseal Process Work?

For more info visit us at www.aeroseal.us