Why Clean Air Ducts? Answer: Because They Get Dirty

In addition to normal accumulations of dust and dirt found in all homes with air ducts, there are several other factors that can increase the need for regular HVAC system cleaning:

  • pets
  • occupants with allergies or asthma
  • cigarette or cigar smoke
  • water contamination or damage to the home or HVAC system
  • home renovation or remodeling projects

Some occupants are more sensitive to these contaminants than others. Allergy and asthma sufferers, as well as young children and the elderly tend to be more susceptible to the types of poor indoor air quality that air duct cleaning can help address.

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NADCA’s rule of thumb for consumers is that “if your air ducts look dirty, they probably are,” and that dirty HVAC systems should be inspected by a reputable, certified HVAC professional. Below are some other reasons homeowners choose to have their air ducts cleaned.

Indoor Air Quality

Indoor air quality is one concern that homeowners have when they decide to investigate air duct cleaning. Your heating and cooling system is the lungs of your home. The system takes air in and breathes air out.

Through normal occupation in a home, we generate a great deal of contaminants and air pollutants, such as dander, dust, and chemicals. These contaminants are pulled into the HVAC system and re-circulated 5 to 7 times per day, on average. Over time, this re-circulation causes a build-up of contaminants in the duct work.

While dirty ducts don’t necessarily mean unhealthy air in your home, school or workplace, they may be contributing to larger health issues or harboring contaminants that could cause serious problems for people with respiratory health conditions, autoimmune disorders or some environmental allergies.

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Energy Savings

According to the U.S. Department of Energy, 25 to 40 percent of the energy used for heating or cooling a home is wasted. Contaminants in the heating and cooling system cause it to work harder and shorten the life of your system. Although filters are used, the heating and cooling system still gets dirty through normal use.

When an HVAC system is clean, it doesn’t have to work as hard to maintain the temperature you desire. As a result, less energy is used, leading to improved cost-effectiveness.

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Source: National Air Duct Cleaners Association (NADCA)

Please contact Aspen Air Duct Cleaning, an approved Aeroseal Dealer, at 1-800-931-6653 or email info@aspenenvironmentalservices.com, for an Air Duct System Inspection and to learn more about how sealing air duct leaks can improve indoor air quality and reduce energy costs.

Aspen Air Duct Cleaning is licensed and ensured, a member of the National Air Duct Cleaners Association (NADCA) and the National Organization of Remediators and Mold Inspectors (NORMI).


40 Amazing HVAC Industry Trends

Heating, ventilation, and air conditioning are what make up the HVAC industry. It’s something that you’ll find in buildings, homes, and even vehicles. We often take these needs for granted, wanting to turn on the heat when we’re cold or the A/C when we’re warm. For owners or operators, the HVAC industry has trends, which must be followed to keep a building healthy.

Regulations drive HVAC industry trends. In the northern US, furnaces must have a 90% efficiency rating, but in southern states, only an 80% efficiency rating is required.

This means HVAC industry trends tend to be fueled by local and regional data instead of an overall set of trends. To discover what is in store for this industry, we must look at emerging technologies, integration, and how local regulations are evolving to get a picture of what to expect in the days and years to come.

The HVAC Industry is Getting a Whole Lot Smarter

  • Many within the HVAC industry are beginning to automate their sales and service processes, allowing them to cut their customer acquisition costs to keep pricing competitive.
  • Smarter technologies, such as they use of smartphone apps, allow building managers to control lighting, ventilation, and other processes with one control point.
  • Better measurements of building environments thanks to the collection and mining of big data and analytic information will allow for more efficient HVAC systems to be installed in the future.
  • At the local level, HVAC contractors will also be using software, SEO, widgets, and other online tools and strategies to help connect with local customers who are researching their system.
  • Mobile solutions will continue to drive innovation within the HVAC industry as more potential customers look to meet their needs through the use of tablets, smartphones, or tablet PCs.
  • As HVAC systems continue to develop innovative, but complex, solutions for buildings, consumers are expected to continue turning toward mobile technologies to set up preventative maintenance and service programs.

There will always be a need for the HVAC industry. The real question of the hour is this: how much demand is this industry expected to see year after year? Much of that will depend on how much innovation can be achieved within the industry. As the world continues to globalize, more information than ever before is at the fingertips of consumers. They can research best practices, installation techniques, and they want mobility like never before.

The Relationship Between Construction and HVAC

  • An increase in new building construction will always provide a similar increase of HVAC unit installations.
  • In both residential and non-residential, HVAC equipment installation are expected to be on the rise in the coming year.
  • From 2014 data, the spending on construction projects for non-residential use rose 4.2% from the year before. In 2016, up to 7% growth could occur.
  • Lodging construction projects with a need for HVAC unit installations saw an increase of 11.3%.
  • Office and commercial construction projects saw increases of 14.7% and 8.4% respectively.
  • Even sewage disposal construction projects with a need for HVAC components saw an increase of 13.6%.
  • Residential storage heater shipments have seen increases of over 20% in the past 5 years for total shipments.
  • Warm air furnace shipments have seen nearly a 23% increase thanks to the increases seen in new construction projects.

Once an HVAC system is installed, it generally needs maintenance only. This creates two unique sectors within the HVAC industry. On one hand, you have the installers who need new construction in order to find the revenues that will keep them in business. On the other hand, you have maintenance and repair personnel who receive an expanded customer base with every new system that is installed. Although the maintenance sector can still thrive when there is limited new construction, the industry as a whole sees a decline and that affects everyone’s revenues. This is why the relationship between the construction and HVAC industries is so critical.

How HVAC Innovations Are Inspiring New Trends

  • Electronic air cleaners are 40x more efficient than a standard filter you would throw away to remove unwanted particles from the air.
  • Rightsizing, system updating, and types of refrigerant used can significantly affect HVAC efficiency.
  • Variable speed heat pumps can help to trim monthly costs by up to 40% for homeowners.
  • Proper insulation for a home or building on its own can improve HVAC efficiencies by up to 30%.
  • 75% of the utility costs of a home come from power that is used for home electronics that are being kept in a “standby” or “off position,” including HVAC equipment.
  • Heating and air conditioning are two of the three most common expenditures for building owners today.
  • A properly maintained air conditioning system will last 10-15 years, depending on the manufacturer and if it was properly installed.
  • Filters must be changed every 2-3 months at minimum to maintain the efficiency of an HVAC system, which helps to fuel ongoing supportive revenues for the industry.
  • Ductless HVAC systems could come to represent up to 15% of the total industry revenues in the next 5 years.

Did you know that someone who lives in a home with air conditioning actually loses some tolerance for heat? Not that this is necessarily a bad thing, but it does go toward showing the importance of installing and using an innovative HVAC system for comfort purposes. With the average system operating at full efficiencies for 10-15 years, it is up to each owner or operator to find a qualified technician in their area to maintain their system. Otherwise the cost of a new HVAC system might come around sooner than necessary, and although that’s not a bad thing for industry revenues, it does take money out of your pocket unexpectedly. We always think our HVAC system will be useful, but if we don’t pay attention to new trends, we could be paying a lot more than expected.

The Global HVAC Industry

  • Analysts forecast HVAC equipment market in China to grow at a CAGR of 8.51% through 2019.
  • The global HVAC industry is expected to have a 4.34% CAGR through 2022. This is expected to generate total revenues of nearly $70 billion in total.
  • Asia-Pacific continues to be the leading revenue generator in the global HVAC market thanks to the increase in demand for split-air conditioners.
  • Global demands for HVAC equipment are expected to increase by 6% annually through 2020.

Both the mature markets for the HVAC industry and the developing markets have a lot of potential. It’s the new construction opportunities in the mature markets, which are fueling new revenues, while in the developing markets, it is innovative products and technician maintenance and/or installation. Although the HVAC market isn’t one of the larger markets in the world today, it is still a solid contributor to local and regional economies and that is why a healthy industry is so important.

HVAC Industry Forecasts

  • The total HVAC industry in the United States is expected to see around $60 billion in revenues in the next 12 months.
  • Industry revenues within the HVAC industry have been growing steadily at a 1% annualized rate since 2008.
  • 28% of the HVAC industry is comprised of single-family homes. Another 6.1% of the industry serves apartment buildings.
  • The healthcare industries contribute just over 13% of the total revenues that are collected by the HVAC industry annually.
  • Manufacturing and industrial applications [10.5%] are just slightly higher than office building applications [10.1%] in terms of HVAC revenues.
  • Demand for HVAC equipment is forecast to increase 6.8% annually through 2019 to reach a total of $20.4 billion.
  • Shipments of HVAC equipment are expected to grow at 6% per year through 2019 to $16.5 billion.
  • Imports are expected to account for a growing share of the demand for all HVAC products, exceeding 25% of the total demand for the first time ever in 2019.
  • 44% of HVAC sales will continue to be unitary air conditioners, which are consistently the largest share of the demand this industry sees.
  • Heat pumps and warm air furnaces are expected to see the highest levels of total growth in the industry.

When the recession started in late 2007, the HVAC industry took the same hit as the construction industry, but their pain didn’t make the mainstream media as often. The recovery being experienced within the industry is still continuing to build slowly, but at least the industry has come to the point where they have a positive annualized growth since 2008 at this point, even if it is at just 1%. The future looks very bright for the HVAC industry. Hopefully another recession won’t come along to damage the progress that has been made in recent years.

Source: Aeroseal; originally written by Brandon Gaille.

Please contact Aspen Air Duct Cleaning, an approved Aeroseal Dealer, at 1-800-931-6653 or email info@aspenenvironmentalservices.com, for an Air Duct System Inspection and to learn more about how sealing air duct leaks can improve indoor air quality and reduce energy costs.

Aspen Air Duct Cleaning is licensed and ensured, a member of the National Air Duct Cleaners Association (NADCA) and the National Organization of Remediators and Mold Inspectors (NORMI).

Aeroseal Commercial: Frequently Asked Questions

Why should ducts in commercial buildings be sealed?  How much energy does the sealing process save?  How does Aeroseal work?  These are the questions we hear a lot and you’ll find the answers below.  If you have any other questions please do not hesitate to contact us – we’re here to help!

Why Should Ducts in Commercial Buildings Be Sealed?  

Duct sealing in commercial buildings cost-effectively saves energy, improves air balance and thermal distribution (comfort and ventilation), and helps comply with building codes and specification for air distribution effectiveness.

How Much Energy Does the Sealing Process Save?

Energy savings are different for each building and HVAC system and obviously depend upon the initial air duct tightness. The Aeroseal Energy Savings Excel spreadsheet can be used to estimate the savings for most types of buildings.

In smaller commercial buildings with air ducts outside the insulation barrier of the building, energy savings can be as much as 30% of HVAC energy use. In large buildings Aeroseal duct sealing can reduce fan-system energy use by as much as 40% and reduce heating and cooling costs by as much as 10%.

As a rough estimate, simple paybacks typically range from 3 to 7 years. In some cases building owners have recovered the investment in Aeroseal duct sealing in less than 18 months.

Is the Sealant Used in Aeroseal Safe?

The sealant material has been certified to UL1381, the industry standard for aerosol duct sealants. It is tested to rigorous requirements for flammability, smoke inhibition, mold growth and durability. The sealant has no OSHA Exposure Limit and no special precautions are required during application. It cures in less than two hours and meets LEED requirements for low VOC emissions.

The dried sealant material is primarily vinyl acetate polymer (VAP), which has been used in chewing gums, latex paints and hair sprays.

How Long Will the Seals Last?

The sealant has a life of over 30 years. 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.

How Do I Know if the Ducts in My Building Need to be Sealed?

The duct leaks can be uncovered several ways. Aeroseal has developed a simple survey that can accurately predict if an air distribution system is leaking excessively. Another method is to review a Test and Balance Report and compare the flow at the HVAC system supply or return fans and sum of the flows measures at the supply diffusers or return grilles. Testing a sample of duct sections for leakage is an accurate way to identify if ducts are too leaky. Aeroseal technicians regularly perform this test.

How Does the Aeroseal Process Work?

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.

How Large of a Leak Can Be Sealed?

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.

What Types of Ducts Can Be Sealed?

Aeroseal is capable of sealing all types of ductwork. It has been successfully applied in rigid metal and flexible air ducts. It has been applied in duct with internal insulation. It has also been installed in duct systems fabricated of ductboard, drywall or masonry blocks.

Aeroseal avoids sealing through VAV boxes or fire/smoke dampers.

Do Ducts Need to Be Cleaned Prior to Sealing?

Extremely dirty ducts should be cleaned.  We recommend that the technician assess the condition of ducts prior to beginning to Aeroseal process.

Source: Aeroseal

Please contact Aspen Air Duct Cleaning, an approved Aeroseal Dealer, at
1-800-931-6653 or email info@aspenenvironmentalservices.com, for an Air Duct System Inspection and to learn more about how sealing air duct leaks can improve indoor air quality and reduce energy costs.

Aspen Air Duct Cleaning is licensed and ensured, a member of the National Air Duct Cleaners Association (NADCA) and the National Organization of Remediators and Mold Inspectors (NORMI).


How Aeroseal works in Commercial Building

The following video chronicles a light commercial duct-sealing project from start to finish. It follows the steps involved from unloading the equipment to the final certificate of completion.


Aeroseal duct sealing is used in commercial buildings around the world to increase energy efficiency and improve comfort and indoor air quality.   This video takes you inside a typical commercial duct-sealing project, highlighting the steps involved in using this safe and easy-to-administer process.

By sealing from inside the ducts, Aeroseal is most effective and least invasive duct sealing solution available.

How Aeroseal Helps Commercial Clients Everywhere:

Aeroseal is the best solution for a large range of Commercial building problems. Whether the problem is energy consumption, poor indoor air quality, or commissioning the HVAC system, Aeroseal is up to the job.

High Energy Consumption

If you want to reduce your energy consumption without a large capital expenditure, you should consider having your ducts tested for leakage.

Duct leakage can more than double fan energy use, and increase heating and cooling costs significantly. According to ASHRAE, just a 20% leakage in an exhaust system can increase fan energy use by 95%.  Your energy savings potential is magnified by the fact that excess flow due to leakage often creates uncontrolled air infiltration through the building envelope or excess outside air intake through the HVAC system.

The investment in Aeroseal duct sealing is typically recovered in 3-7 years.  According to the U.S Department of Energy and several other sources, Aeroseal duct sealing is one of the best energy saving solutions for property owners – and one of the most cost effective.

Poor Exhaust from Desired Areas

Duct leakage has been linked to bad Indoor Air Quality, poor humidity control and health hazards such as sick building disease and the spread of mold and other contagions within the building.

If you are having trouble getting the correct air changes per hour or trouble pressurizing some zones within your building, it could be due to duct leakage. When 20% or more of the air that is passing through your ducts is leaking out, it is not surprising that some of the zones are not getting enough air.

In tall buildings seasonal stack effects and wind loading often increase the ventilation problems from improperly sealed toilet and kitchen exhaust systems.  Buildings with self-regulating exhaust dampers are particularly prone to excessive energy consumption and poor indoor air quality associated with leaking exhaust shafts.

Problems Identified During Building Commissioning

In a recent survey, over 74% of commissioning professionals agreed that buildings have significant duct leakage.

If the HVAC cannot be properly balanced or you are not getting adequate flows through some supply diffusers or return grilles, you should consider getting your duct system sealed with Aeroseal. Aeroseal is able to seal leaks in otherwise inaccessible duct systems is both new and existing buildings.

Problems Identified by Test and Balance Report

If a Test and Balance report shows that you are not getting adequate flows to some grilles, or that the grille flows do not add up to the flow at the fan, you should consider getting your duct system sealed with Aeroseal. Aeroseal is able to seal leaks in otherwise inaccessible duct systems is both new and existing buildings.

Increased Cooling or Heating Capacity Needs

If your cooling or heating needs have increased, perhaps due to higher occupancy, you may be able to meet the increased needs simply by sealing the leaks in your duct system.

If your ducts are leaking 20% of the air that they are supposed to be delivering to the zones, simply sealing those leaks can increase your ability to cool zones with increased cooling loads. Aeroseal generally seals 80-90% of the leakage encountered.

Source: Aeroseal

Please contact Aspen Air Duct Cleaning, an approved Aeroseal Dealer, at 1-800-931-6653 or email info@aspenenvironmentalservices.com, for an Air Duct System Inspection and to learn more about how sealing air duct leaks can improve indoor air quality and reduce energy costs.

Aspen Air Duct Cleaning is licensed and ensured, a member of the National Air Duct Cleaners Association (NADCA) and the National Organization of Remediators and Mold Inspectors (NORMI).

A New Way to Reduce Multifamily Air Leakage

While tight exterior envelopes have become standard for single-family homes, they have been slow to reach the multifamily sector. Multifamily buildings have many of the same leakage paths as houses, as well as additional paths hidden in walls or other cavities that are difficult to seal with conventional methods. Researchers at the Western Cooling Efficiency Center (WCEC) at the University of California at Davis recently developed an aerosol sealant to seal leaks in building walls, floors, and ceilings. The process can be more effective and convenient than conventional methods for sealing envelopes, because it requires less time and effort, and it seals the leakage area more quickly.

In 2014-15, researchers at the Center for Energy and Environment (CEE) and WCEC conducted a project to determine whether this sealant could be used in multifamily buildings. At the start of this project, the aerosol envelope-sealing technology was in precommercial development. The project team performed aerosol envelope-sealing demonstrations on six multifamily buildings. Three of these buildings were new construction and three were existing construction. While the work was performed on Minnesota multifamily buildings, the air leakage reduction results are generally applicable to all multifamily buildings.

How the Technology Works
The aerosol envelope-sealing technology that was used in this project was developed by WCEC. It uses an automated approach to produce extremely tight envelopes. Air is blown into a unit while an aerosol sealant fog is released in the interior. As air escapes the building through leaks in the envelope, the sealant particles are carried to the leaks, stick to the edges of the leaks, and eventually seal them. Standard house or duct air leakage test fan is used to pressurize the building and also provide real-time feedback and a permanent record of the sealing. The technology is thus capable of simultaneously measuring, locating, and sealing leaks in a building.

Watch a video on how Aeroseal works:

Energy Program and Code Envelope Airtightness Requirements
There is a growing recognition of the need for tight multifamily building envelopes. The 2012 and 2015 versions of the International Energy Conservation Code require that one- to three-story multifamily buildings meet the residential energy code envelope tightness requirement of 3 ACH50. In addition, the EPA Energy Star Multifamily High Rise Requirements include a requirement for a maximum air leakage rate of 0.3 CFM50/ft2 of enclosure (EPA 2013). LEED v4 also has a prerequisite of 3 ACH50 for one- to three-story multifamily buildings with air infiltration credits for tighter envelopes. There is a prerequisite of 0.3 CFM50/ft2 or air-sealing checklist for midrise (four- to eight-story) buildings and annual energy use points for tighter envelopes. Effective air sealing technologies are necessary to meet these requirements.

Study Objectives
The Aeroseal study on new and existing multifamily buildings had several objectives.

  • Refine the aerosol sealing technique.
  • Measure leakage and noise transmission reduction.
  • Determine how to incorporate aerosol technique into sealing strategy (for example, pre-seal “large” leaks and protect horizontal surfaces).
  • Estimate the labor and time needed for sealing.
  • Model energy savings and ventilation/inter-unit airflow.

Air Sealing
Aerosol envelope air sealing was performed on 9 units in three existing-construction multifamily buildings and 18 units in three new-construction multifamily buildings. The air-sealing protocol was adapted based on experience with past laboratory and field projects. The type of sealant deposition protection measures, temporary seals, manual presealing, and time required for all tasks were broken out for a subset of the sealed units. Multipoint, compartmentalization tests to measure total-unit air leakage were conducted on all units before and after the sealing. In addition, guarded air leakage tests were performed to break out exterior and interior envelope leakage. These tests used an additional fan to pressurize an adjoining unit or hallway during an air leakage test of the target unit. The reduced blower door flow rate of the target unit is approximately equal to the leakage to the adjoining space being pressurized. Pre- and postacoustic tests and documentation of sealant locations using a fluorescent dye in the sealant and black-light photography were conducted for some of the units.

Airflow and Energy Use Modeling
The airflow and energy use modeling was performed with EnergyPlus simulations to determine building airflows from wind, stack, and mechanical effects as well as the air leakage characteristics of each unit. Whole-building simulations often assume a constant air infiltration rate to represent the effects of uncontrolled infiltration driven by the natural forces of wind and stack effect and unbalanced mechanical ventilation. However, comparing the performance of different multifamily envelope tightness and ventilation strategies requires simulations that compute infiltration. The building airflows are computed from detailed information on the location and size of envelope air leaks along with inside air temperature and relative humidity (RH), outside air temperature and RH, wind speed and direction, and mechanical ventilation flow rates. The models were developed for four ventilation strategies, and the energy consumption was compared for each strategy before and after sealing.

Aerosol Sealing Process
The air sealing process consisted of several steps, as follows.

  1. Preseal large gaps. Gaps wider than 3/8 to 5/8 inch and leaks located where the aerosol will not stay in suspension should be manually sealed.
  2. Cover finished horizontal surfaces. Some of the sealant will settle on horizontal surfaces during the aerosol sealing process. These surfaces should be protected with plastic, duct mask, or masking tape.
  3. Set up equipment and perform sealing. One sealant spray nozzle is typically placed in every bedroom and living area. The unit is then pressurized to about 100 Pa while an aerosol sealant fog is released in the interior. The sealing typically takes 45 minutes to a couple of hours.
  4. Remove coverings and clean surfaces. Windows must be opened and fans set to high to purge remaining sealant; surface protection should be removed, and any remaining residue cleaned up.
  5. Conduct a postsealing air leakage test. This test should be conducted after all penetrations in the envelope have been made.

Aerosol envelope sealing was performed on a convenience sample consisting of 18 units in three new- construction buildings and 9 units in three existing-construction buildings, as described above.

The research team conducted the sealing using an equipment design modified from previous field tests and the protocol described above under “Methodology.” There was reduction in unit leakage for four new-construction units and six existing-construction units, respectively. In general, the sealing rate was greatest for the first 30 minutes and decreased steadily thereafter.

The aerosol envelope sealing of new-construction and existing-construction units successfully demonstrated high levels of air leakage reduction with no damage to the finished surfaces. For the new-construction units, the reduction varied from 67% to 94% with an average of 81%. For all of the units the total leakage was more than 50% tighter than the 3 ACH50 code requirement for low-rise residential buildings, and half of the units met the Passive House tightness requirement of 0.6 ACH50. In addition, all of the units were at least 80% tighter than the EPA Energy Star Multifamily High Rise requirement of 0.3 CFM50/ft2.

Labor Requirements
The total time required to complete the ten tasks for the air sealing process was tracked for three of the six buildings. The average task labor times for all sealed units for the three buildings are shown. The total time per unit for the sealing process varied from 14 to 22 person hours. However, this was a research project with staff that was being trained on the process. With trained personnel labor time might well be reduced by a factor of 2 or greater. Labor time would be reduced by

  • presealing large leaks;
  • performing sealing at a time when there are a minimum of finished surfaces to cover;
  • and using new, more portable and automated equipment.

Energy Savings Modeling: New Construction
The new-construction modeling compared the energy performance of two buildings. The units in the first building had a total (exterior and interior) envelope leakage of 3 ACH50. The units in the second building, which were sealed using the aerosol process, had a total envelope leakage of 0.6 ACH50, for a reduction of 80%. This 80% reduction in envelope leakage approximates the 81% average reduction for the aerosol sealing of the 18 new- construction units completed for this project. These savings would be applicable to a building that needs to meet a code-required tightness level of 3 ACH50 and that uses aerosol sealing to exceed the code requirement. This might be done either for a high-performance utility program or for a green-building rating program.

The 80% reduction in envelope leakage also saved heating energy. This can be translated into annual cost savings. For example, a system using balanced ventilation would save 27 therms at $0.58/therm for an annual cost savings of $15. Thus the cost of sealing by the aerosol method would have to be $150–225 per unit for a 10–15-year payback. This assumes that the aerosol process is an add-on that reduces the leakage of a unit in a low-rise multifamily building from the code-required level to a very tight level. However, aerosol sealing might eliminate the need to achieve a tighter envelope using conventional methods and higher levels of quality control. In that case it might actually cost less than conventional alternatives.

When the modeling for this project was performed, researchers expected that the 3 ACH50 code requirement would apply to the total unit leakage. However, Minnesota code officials have indicated that the 3 ACH50 requirement applies to the exterior leakage only. This allows units to be leakier than they would be if the requirement applied to the total leakage. Increasing the leakage of the baseline model results in higher absolute savings for the new-construction sealing, and is closer to the savings reported for the sealing of existing construction.

Energy Savings Modeling: Existing Construction
The modeling for existing construction focused on comparing the energy performance of an existing building that was sealed to the low-rise multifamily code requirement for new construction. The two total envelope leakage levels modeled for the existing buildings were 9.5 ACH50 and 3.0 ACH50.

The results show an 11% to 25% reduction in heating energy use due to sealing the envelope with annual gas savings of 41 to 68 therms and cost savings from $24 to $39, which may not be sufficient for many building owners. However, the modeling results were based on a 68% reduction from a starting leakage of 9.5 ACH50, and the average pre-sealing leakage of the nine existing units was over 14 ACH50. A pre-sealing leakage of 15 ACH50 and a reduction of 75% would increase annual savings by about a factor of two. The simulations assumed that 43% to 47% of the total leakage was to the exterior, but if the percent exterior leakage for the models was 68%, the savings would have been about 50% greater. Under certain factors, leakier units could see higher savings of three times or more (e.g. $70 to $120 per year).

Utility Program Recommendations
Existing Construction. Three Minnesota utilities provide incentives for envelope air sealing. The CenterPoint Energy/Xcel Energy Multifamily Building Efficiency program includes envelope air sealing as a custom measure. To qualify for an incentive, the air sealing work must have a payback of less than 20 years, representing the life of the measure. The Minnesota Energy Resources Multifamily Direct Install Plus program lists envelope air sealing as one of the measures targeted for investigation, and air sealing work may qualify for a custom rebate. We recommend that all Minnesota utility programs for existing multifamily buildings include incentives for envelope air sealing.

Energy Savings Calculation. The State of Minnesota Technical Reference Manual for Energy Conservation Improvement Programs (2016) includes an algorithm for residential and small commercial buildings, but it is not directly applicable to multifamily units. There is currently no generally accepted methodology for computing multifamily envelope air sealing savings. The current calculation includes a value for n_heat, which is the conversion factor from leakage at 50 Pa to leakage at natural conditions, building height, and exposure level. The modeling results from this project indicate that a value of 25 should be used for n_heat of existing multifamily buildings with less than 50 CFM of continuous unbalanced mechanical ventilation that are well shielded from wind. The value should be reduced to 21 for normal wind shielding and 19 for exposed shielding. The relationship between exterior envelope leakage reduction and space heating savings is not only impacted by the type of ventilation system and wind shielding, the building height and climate also affect energy savings from air sealing. Similar building air flow modelling should be performed to properly relate sealing reductions to energy savings for other parts of the country.

An evaluation of the building ventilation system should be conducted and recommended upgrades completed when any significant exterior envelope air sealing is performed. Exterior air sealing is not recommended when units do not have a mechanical ventilation system.

New Construction. Xcel Energy and CenterPoint Energy offer design assistance programs for commercial and industrial new construction and major renovation, including construction and renovation for multifamily buildings. The program[s] provides consulting services and energy modeling, as well as electricity and natural gas efficiency implementation rebates. Although a tighter building envelope and associated air infiltration reduction is not a standard measure for the program, these factors can be modeled if requested by the design team. We recommend that the modeled air infiltration results from this demonstration project be used for baseline and reduced envelope tightness infiltration values for design assistance programs.

The airflow modeling conducted for this project suggests that for Minnesota multifamily buildings design assistance program building energy models should use a baseline air infiltration rate of 0.16 ACH for buildings with normal wind shielding. The baseline is reduced to 0.13 ACH for well-shielded buildings and increased to 0.18 ACH for exposed buildings. The percent reduction in modeled air infiltration should be the difference between the measured exterior envelope leakage and the low-rise residential code requirement of 3 ACH50. Given the high level of energy savings achieved in this demonstration project, aerosol envelope sealing may be one of the most cost-effective sealing methods for multifamily units that are required to meet more-stringent compartmentalization requirements.

Source: Aeroseal; written by Dave Bohac; originally appeared in Home Energy magazine

Please contact Aspen Air Duct Cleaning, an approved Aeroseal Dealer, at 1-800-931-6653 or email info@aspenenvironmentalservices.com.

Aspen Air Duct Cleaning is licensed and ensured, a member of the National Air Duct Cleaners Association (NADCA) and the National Organization of Remediators and Mold Inspectors (NORMI).

Contact us for an Air Duct System Inspection and to learn more about how sealing air duct leaks can improve indoor air quality and reduce energy costs.

The Homeowner’s Guide – Why Choose a NADCA Member?

NADCA Members Follow the Industry Standard

NADCA sets the industry standard for HVAC system cleaning. When done correctly, HVAC cleaning is a very beneficial service for your home. NADCA’s dedication to quality promotes a higher standard of performance for all of its members—which can help give homeowners peace of mind.

In order to become a NADCA member, a company must:

Have at least one NADCA certified Air Systems Cleaning Specialist (ASCS) on staff.

Maintain general liability insurance.

Agree to clean according to ACR, the NADCA Standard.

Comply with NADCA’s Code of Ethics.

All ASCS certified individuals must acquire continuing education credits to maintain certification each year.

Finding a QUALIFIED Contractor

NADCA provides the following tips to help homeowners hire a qualified contractor for their HVAC system and air duct cleaning needs.


Ask for proof of NADCA membership and certification and visit NADCA’s find a Professional Directory at www.nadca.com to verify NADCA membership.

Ask for proof of insurance.

Make sure the contractor can provide proof of proper license(s), as applicable.


Ask the contractor to assess and explain the service to be provided.

Ask the contractor to specify which components will be cleaned as part of the service, such as the air ducts (the supply and return), coils, drains, registers, grills, etc.

Verify that the contractor will limit the release of dust, dirt and debris into your home during the cleaning.

Make certain that the contractor will use both agitation and vacuum collection while cleaning.

Ask the contractor to inform you if any chemicals will be used as part of the cleaning, and provide a safety data sheet for products used.

Questions? Be Sure to Ask Your Contractor!

Source: The National Air Duct Cleaners Association (NADCA)

Aspen Air Duct Cleaning is licensed and ensured, a member of the National Air Duct Cleaners Association (NADCA) and the National Organization of Remediators and Mold Inspectors (NORMI).

Contact us for an Air Duct System Inspection and to learn more about how sealing air duct leaks can improve indoor air quality and reduce energy costs: 1-800-931-6653 or email info@aspenenvironmentalservices.com.

Aspen Air Duct Cleaning is an approved Aeroseal Dealer.

Looming Code Changes

Near the end of 2017, ASHRAE Journal published an interesting article about building codes development and adoption.

Fast forward, 2018 has already been a noteworthy year for building codes.

More specifically, with the latest release of IECC and other code changes, some have called 2018 the “Year of the Duct.” There are looming code changes for duct system standards you should know. We’ve highlighted a few of them below.

SPC 215: “This standard specifies a method of test to determine leakage airflow and fractional leakage of operating HVAC air distribution systems, and determines the uncertainty of the test results.” 

California Title 24: “The California Title 24 Building Energy Efficiency Standards are designed to ensure new and existing buildings achieve energy efficiency and preserve outdoor and indoor environmental quality. These measures (Title 24, Part 6) are listed in the California Code of Regulations. The California Energy Commission is responsible for adopting, implementing and updating building energy efficiency. Local city and county enforcement agencies have the authority to verify compliance with applicable building codes, including energy efficiency.” 

ASHRAE 189.1: “Standard 189.1 provides total building sustainability guidance for designing, building, and operating high-performance green buildings. From site location to energy use to recycling, this standard sets the foundation for green buildings by addressing site sustainability, water use efficiency, energy efficiency, indoor environmental quality (IEQ), and the building’s impact on the atmosphere, materials and resources.”

ASHRAE Handbook: See the following chapters focus on duct design and construction:

  • 02 Fundamentals | 21 Duct Design
  • 02 HVAC Systems and Equipment | 19 Duct Construction

SMACNA HVAC Duct Construction Standards, 4th edition: Read about this code update for duct tightness that went into review last year. Anticipation is building for what’s next.

IECC 2018: With the typical time difference between code development and code adoption being three years, watch for many builders and building code authorities to adopt IECC 2012/2015.

Want to learn more about the changing and growing building codes? We’ve got a couple upcoming free webinars you might like.

First, commercial sheet metal business experts John Hauser and Mike McCarthy from Eastern Metalworks will be discussing their experiences in the sheet metal industry, synergies of duct sealing for sheet metal businesses, and more on Wednesday, April 25, 2018 at 1:30pm ET (10:30am PT). Learn More at www.aeroseal.com/success-series-webinar-2/

Second, BPI Technical Director John Jones will be sharing insights into cracking the new codes for residential new construction on Thursday, May 17, 2018 at 3:00pm ET (12:00pm PT). Learn More at www.aeroseal.com/res/2018-webinar-series/building-codes/

Source: Aeroseal

Please contact Aspen Air Duct Cleaning, an approved Aeroseal Dealer, at 1-800-931-6653 or email info@aspenenvironmentalservices.com, for an Air Duct System Inspection and to learn more about how sealing air duct leaks can improve indoor air quality and reduce energy costs.

Aspen Air Duct Cleaning is licensed and ensured, a member of the National Air Duct Cleaners Association (NADCA) and the National Organization of Remediators and Mold Inspectors (NORMI).

American Dental Association Improves Ventilation, Meets Code with Aeroseal

For the past decade, Mike Kosinski and his team of experts at CEPro Inc. have been taking great care of the historic ADA building on Chicago’s Near North Side. Built in 1965, the 23-story skyscraper has undergone numerous upgrades and renovations, but none as transformative as those being planned for the building’s 4th-floor medical laboratory. Unfortunately, leaks in risers that connect the labs fume hoods to two rooftop fans were making adequate ventilation impossible. Not able to meet stringent exhaust code specification, some of the fume hoods were simply rendered inoperable. Without a solution to the problem, laboratory renovation was impractical. Talks of having to relocate the entire facility had begun to surface.

Each of the building risers were actually encased in individual concrete structures that draped over the side of the building’s exterior. That meant accessing the enclosed ductwork to seal the leaks would require nothing less than major building demolition. With no alternative, the leaks continued to plague the facility.

In Brief

  • Building: American Dental Association Building
  • Location: Chicago, Illinois
  • Building Managers: CEPro Inc.
  • Aeroseal Contractor: Airways Systems Inc.
  • Goal: Meet code for proper lab fume hood operations
  • Before Aeroseal: 2,733.00 CFM of leakage
  • After Aeroseal: 606 CFM of leakage
  • Results: Aeroseal eliminated 2,127 CFM of leakage. With proper exhaust now possible, all fume hoods are back up and operational. Renovation on schedule.

That’s when CEPro’s Mike Wessel, learned about a new approach to duct sealing that worked from the inside of the duct to find and seal leaks. After initial research and explanatory meetings with building management, Wessel got the go-ahead for a preliminary duct-sealing project. Airways Systems’ Joe St. Pierre got the call and soon, he and his team arrived on site to seal 3 of the leaky shafts.

When finished, the print out report generated by the Aeroseal system provided immediate results – Aeroseal reduced leakage by as much as 94.5%. A week later, Joe got the go ahead to seal the rest of the leaky shafts. In the end, Joe and his team reduced leakage by more than 2,000 CFM, more than enough to meet code and get all fume hoods up and operational. Renovation of the ADA lab is back on the schedule and moving forward.


My story is simple. I was skeptical that the Aerosealing would work. I watched the process and found it magical because it was so simple. And in the end, we went from having doubting clients to having customers that were gleeful and happy, bristling with excitement because their life just got infinitely easier.”

There was simply no other practical solution. If not for the Aeroseal, we would be moving the lab right now, incurring millions of dollars to change strategy and writing off millions in investment that had already been made in the building. Aeroseal extended the life of their investment – I can’t even estimate the total cost savings this represents.”

Michael Wessel
Project Engineer
CEPro, Inc.

Source: Aeroseal

Please contact Aspen Air Duct Cleaning, an approved Aeroseal Dealer, at

1-800-931-6653 or email info@aspenenvironmentalservices.com, for an Air Duct System Inspection and to learn more about how sealing air duct leaks can improve indoor air quality and reduce energy costs.

Aspen Air Duct Cleaning is licensed and ensured, a member of the National Air Duct Cleaners Association (NADCA) and the National Organization of Remediators and Mold Inspectors (NORMI).

Overview of the Air Duct Cleaning Process

NADCA members are accustomed to handling a variety of projects for commercial and industrial buildings. NADCA’s presence in the commercial HVAC industry is growing steadily as education about our members’ services grows. It is becoming increasingly common for project proposals to specify the presence of an ASCS certified individual on a commercial job.

When hiring a NADCA member, an optimal level of performance should be expected. Technicians are required to adhere to the industry’s standards and guidelines, and inform the client of any obstacles that may prevent doing so. NADCA members are able to able to answer most questions about a particular project, including safety issues and are able to provide proof that the job has been done correctly.  

Through clear, concise communications, air duct cleaning contractors can provide their clients with a better understanding of the work to be undertaken and demonstrate that the project will be well managed. Clients should also clearly define the scope of work they desire and are encouraged to utilize NADCA’s General Specifications for the Cleaning and Restoration of Commercial Heating, Ventilating and Air Conditioning Systems.

HVAC system cleaning projects require a game plan. Project length can vary from a few hours to six months or more. The size and scope of the project are the two key elements that will have an impact on the length of time necessary for completion. The entire duct cleaning project will run smoothest when an in-depth review is first conducted to determine the expectations and desired outcome for both the customer and duct cleaning company. 

  • During cleaning, the entire HVAC system is placed under continuous negative pressure — with a vacuum — to prevent the spread of contaminants.
  • Continuous negative pressure allows very fine particles to be removed from the system as they become airborne, ensuring that these particles are not released into the living space when the system is turned on after cleaning.
  • This negative pressure also serves to extract the loosened contaminants, which are collected and removed from your home.

Often, HVAC system components collect significant amounts of debris and particulate during construction activities within a building. NADCA recommends that newly installed HVAC systems or HVAC systems undergoing renovation be verified clean and protected before the system is permitted to operate.

Source: From NADCA’s “The Facility Manager’s Guide to Sick Buildings & Indoor Air Quality.”

Aspen Air Duct Cleaning is licensed and ensured, a member of the National Air Duct Cleaners Association (NADCA) and the National Organization of Remediators and Mold Inspectors (NORMI).

Contact us for an Air Duct System Inspection and to learn more about how sealing air duct leaks can improve indoor air quality and reduce energy costs: 1-800-931-6653 or email info@aspenenvironmentalservices.com.

Aspen Air Duct Cleaning is an approved Aeroseal Dealer.

Remember to Clean Your Clothes Dryer Vents

Facts about home clothes dryer fires

  • 2,900 home clothes dryer fires are reported each year and cause an estimated 5 deaths, 100 injuries, and $35 million in property loss.
  • Failure to clean the dryer (34 percent) is the leading cause of home clothes dryer fires.
  • More home clothes dryer fires occur in the fall and winter months, peaking in January.

Clothes dryer fire safety messages

It is important for community residents to know how to keep themselves safe from fire. Use the following fire safety messages to teach people about clothes dryer fire safety.

Clothes dryer do’s


  • Have your clothes dryer installed by a professional.
  • Make sure the correct electrical plug and outlet are used and that the dryer is connected properly.
  • Read manufacturers’ instructions and warnings in use and care manuals that come with new dryers.


  • Clean the lint filter before and after each load of laundry. Don’t forget to clean the back of the dryer where lint can build up. In addition, clean the lint filter with a nylon brush at least every six months or more often if it becomes clogged.
  • Clean lint out of the vent pipe every three months.
  • Have your dryer cleaned regularly by a professional, especially if it is taking longer than normal for clothes to dry.


  • Inspect the venting system behind the dryer to ensure it is not damaged or restricted.
  • Put a covering on outside wall dampers to keep out rain, snow and dirt.
  • Make sure the outdoor vent covering opens when the dryer is on.
  • Replace coiled-wire foil or plastic venting with rigid, non-ribbed metal duct.
  • Have gas-powered dryers inspected every year by a professional to ensure that the gas line and connection are together and free of leaks.
  • Check regularly to make sure nests of small animals and insects are not blocking the outside vent.
  • Keep the area around the clothes dryer free of items that can burn.
  • If you will be away from home for an extended time, unplug or disconnect the dryer.

Clothes dryer don’ts

Don’t use a clothes dryer without a lint filter or with a lint filter that is loose, damaged or clogged.

  • Don’t overload the dryer.
  • Don’t use a wire screen or cloth to cover the wall damper. They can collect lint and clog the dryer vent.
  • Don’t dry anything containing foam, rubber or plastic. An example of an item not to place in a dryer is a bathroom rug with a rubber backing.
  • Don’t dry any item for which manufacturers’ instructions state “dry away from heat.”
  • Don’t dry glass fiber materials (unless manufacturers’ instructions allow).
  • Don’t dry items that have come into contact with anything flammable like alcohol, cooking oils or gasoline. Dry them outdoors or in a well-ventilated room, away from heat.
  • Don’t leave a clothes dryer running if you leave home or when you go to bed.

Source U.S. Fire Administration (USFA)

View a video on the NADCA Dryer Exhaust Duct Performance Standard (DEDP):


Please contact Aspen Air Duct Cleaning, an approved Aeroseal Dealer, at 1-800-931-6653 or email info@aspenenvironmentalservices.com.

Aspen Air Duct Cleaning is licensed and ensured, a member of the National Air Duct Cleaners Association (NADCA) and the National Organization of Remediators and Mold Inspectors (NORMI).

Contact us for an Air Duct System Inspection and to learn more about how sealing air duct leaks can improve indoor air quality and reduce energy costs.