We’ve come to know that some parts of a house are generally going to be hotter than others in the summer months. Certain rooms of the house bake, while others are nice and comfortable. Why do we settle? The truth is that no house needs to operate like this. When you understand stratification and convection currents, you quickly learn there are simple design strategies to help prevent temperature deltas within the home. 

Why are there problems in the first place? 

Homes often experience stratification. Depending on the weather conditions of the season, the temperature between a basement and second story of a building may vary 15-20 degrees. That’s quite a difference! We could share the complex physics behind this, but the cliff notes version is essentially a layering effect that allows pockets of air with different core temperatures to remain intact, even if a building’s central HVAC system is in place. Drafts and stratification are usually due to interior temperature deltas causing microclimates stratification and convection currents. You experience convection currents and stratification which often manifest as drafts in stairwells and around bad windows or poorly insulated walls and attics which often also cause cold floors. You end up with microclimates throughout the home and most people live this way without giving it much thought.  

But, what if we gave it some thought…???

The truth is that designers have been giving it thought for a long time, and we see it all over the strategies in a Passivhaus design. A Passivhaus, or even a Darn Good House concept, employs techniques that are focused on reducing thermal bridging, drafts, issues at openings, and more. While a Passive House design is focused on energy savings and passive strategies, a huge focus is also on effective insulation. When you have a solidly-insulated air sealed house you have an energy efficient house; these go hand in hand. The side benefit is that you end up with a home that has stable temperatures in both extreme hot and extreme cold environments, and from the lower levels to the upper levels in the home. 

How to Avoid Stratification:

• Build a Passive House from the start. If you are working on a new project, take the time now to build a structure that is well insulated from day one. This will help ensure you can avoid convection currents and stratification. Your upper stories can be comfortable and similar to those temperatures in your basement level. 
• Fix an existing problem. If you are working with an existing building that has issues, hope is not all lost. There are a few core things you can do:
  1. High Performance Windows: Replacing openings in the home with high performance windows and doors will help reduce the drafts and swings in temperature you experience throughout the home. 
  2. Continuous Insulation: Proper continuous insulation in walls becomes a solid barrier for thermal bridging. Often a little investment in insulation can go a long way to reduce drafts, energy loss, and ultimately stratification. One simple space to insulate that many don’t even think about is the basement/foundation walls, as well as the horizontal slab. 
  3. More Attic/Roof Insulation: One of the biggest energy penalties comes from poorly insulated and poorly air sealed attics and roofs.  Attics and roofs can account for as much as 40% of a building’s energy losses.  
  4. Air sealing: Find all the leaks you can and seal them up. It is hard in retrofit situations, but made easier with a thermal imaging gun and a blower door.  

We know firsthand how this works. Our owner, Todd Collins, purchased a great house in a great location, but it was built in typical 1970’s construction practices where, sadly, he experiences stratification on a daily basis. He’s combatted this by heavily insulating his attic and incorporating new energy efficient windows. It’s not a perfect solution, but it has helped significantly. We can’t always build a brand new home that is energy efficient from the start; instead we find ourselves working within the framework of a house we purchase. 

Over the years, our culture built homes that simply aren’t the most efficient… and unfortunately, we are still building marginally efficient homes.  However, today we have the knowledge to build highly energy efficient homes and structures. In turn, we’re less reliant on outside energy sources to regulate our spaces, AND we end up with more consistent comfort throughout the entire building. Quality building products and Passive House design strategies help to make any space more comfortable and more efficient. 

One of the big debates in construction sounds a lot like we’re talking about belly buttons, but we’re actually talking about window construction:  innie vs. outie! In construction this great debate has been going on for some years and it can be confusing to know what the right solution is for your project. Each style has been used in various ways over the years, but if you’re like us, and concerned about thermal performance and energy savings, you will want to pay attention. 

The Basics of Innie & Outie Window Construction

Outie Window Construction:

Outie windows are constructed with the glazing of the window set flush to the outside of the wall assembly – typically with a “nail fin.” These are the types of windows most Americans are used to seeing in a home. 

Pros:

• Easier Installation:  Installed with nailing flanges to the outer face of the wall. 
• Deeper interior sill: Interior sill leaves a small ledge.
• Simple Drainage: No exterior window sill to be concerned with.
• Conventional looking: This is what most people are accustomed to, know, and understand. Many homeowners like to have a little sill to place plants or other decorations. 
• Easier for continuous insulation: When windows are set on the outside, things line up more, and the water and control layer is the face of the continuous insulation. 

Cons:  

• More thermal bridging: Since window assembly is on the exterior shell of the home, there are more thermal considerations to deal with. Often ThermalBuck is a good solution for this, but the simple fact of the location means higher heat loss and greater thermal bridging. 
• More Instability: Since the window isn’t fully framed into the wall itself, and is instead screwed on with flanges, the window often just “sits in” the space, rather than is fully part of the wall like its counterpart. 
• Wind-washing:  Because the window is to the exterior, wind will cool it down in winter and warm it in summer more readily. 

Innie Window Construction

Innie Windows are a window construction style where the glazing of the window is set at the middle of the wall. Many people enjoy the overall look of Innie Windows, but don’t even realize just how efficient they can be! Take a look at some of the pros and cons of Innie Window assemblies:  

Pros:

• Weather Protection:  Since Innie Windows are not on the direct outer surface of a wall, the window is protected more from rain and wind. 
• Improved Thermal Performance:  Since the glazing is within the wall’s depth, the window at large is more insulated from the thermal envelope of the building. 
• Greater Support:  Innie Windows are secured and supported by a full frame, rather than just screws on a flange. 
• Solar shading: Recessed glazing provides greater shade from the sun throughout the day. 
• Better thermal performance: The glazing being within the wall’s depth keeps the glazing within the insulated thermal envelope
• Better for Passive House design: In Passive House design, every little bit of energy performance matters; ultimately Innie designs can help the overall performance of a home!
• Aesthetic:  Some architects and homeowners prefer the look of an inset window.  
• Wind protection: from “Wind-washing” 

Cons: 

• Greater Complexity: An Innie Window is much more complex to install, as it creates concerns not only for the window itself, but for the exterior sill and surround. 
• Require thick wall assemblies: Innies are not very common in 2×4 or 2×6 construction. Instead, you’ll find them in Double Stud designs, or Phoenix Haus wall assemblies. 
• Exterior Sill Detailing Needs:  Requires a solid weather-resistant exterior sill and special considerations for this design. 

It’s easy to see why Innie Windows are becoming a more popular choice for builders. Windows are a hot spot for thermal bridging and while there are a lot of things we can do with insulation construction, supporting products, and the window product itself, we also know that if you’re going for energy savings, the placement of the window itself makes a big difference. It may only be a few inches in, but Innie Windows can provide a solid improvement in energy performance, especially if you’re going for a Passive House certification where every bit of help may make a difference between getting certified or not. 

Still not sure if Innie Windows are right for you? Our team is ready to help you understand if they’re applicable for your project, and if so, how you can best approach the project and make sure everyone is on board. 

Sometimes homes are built in places with noises we can’t control. Whether it’s a plane overhead, a train nearby, or a loud neighbor who likes to sing off-pitch. If you find that there are noises you’d like to keep in, or out, from your sanctuary of a home, the insulation you use is quite important. The cotton-candy looking stuff simply won’t do. You need something more durable, more sustainable, more sound-blocking, and all around so much more. 

When people are looking for increased sound barriers, more sustainable temperature control, safer materials from rot and fire, they typically turn to mineral wool insulation. And, we can see why! Let’s take a quick look at why this stuff is so amazing!

Mineral Wool Insulation is considered ideal for a number of reasons: 

Fire Resistance

Mineral wool is a winner for so many situations because it has a melting point of 2150 degrees F. Compare that with the average range of house fires of 1200-1400 degrees F. You realize quickly that the material simply doesn’t catch fire in an average residential fire, and as a result, it doesn’t allow fire to spread. Mineral wool is ideal as well because when heated, it doesn’t release toxic gases.  

Rot Resistance

Mineral wool insulation is an ideal material in areas typically prone to rot. Mineral wool insulation is permeable, which allows vapor to pass through, which is extremely helpful in Vapor Open Air Tight design. It also has no food source, so mildew, mold, and bacteria have no interest in setting up shop around this material. If concerns for mold or allergies are paramount, then mineral wool is a material you want to consider. 

Sound Dampening

Mineral wool has been a go-to insulation when you need quality acoustical barriers. Mineral wool is denser than conventional insulation, making it ideal for minimizing and absorbing sound. Environments that require better acoustical barriers, like concert halls, theaters, and classrooms, employ mineral wool. In a home, it can be a great asset for those that simply want a quieter home. 

Versatility

Mineral wool insulation is a very versatile product that allows application in many different situations. There are many ways to detail around windows and doors to include thermal buck, frame extensions, sill extensions, all while using mineral wool to reduce thermal bridging. (Learn more about continuous insulation and how mineral woold can support this technique.) Plus, mineral wool is the perfect addition for renovating with a continuous insulation approach.

Durability

Mineral wool insulation has a history of longevity, with minimal shrinkage, crumbling, or changing shape even with major temperature changes. It requires very minimal maintenance and rarely needs to be replaced. The natural properties of the mineral wool consistency provide excellent thermal protection from extreme climates (both warm and cool). This makes for a more comfortable home AND a more comfortable energy bill!

Mineral wool is clearly a great choice for so many applications. Whether the main concern is safety, sound, sustainability, or some combination of these, mineral wool insulation can be helpful for both commercial AND residential projects. Yes, there are other options for continuous insulation in a project, but we’ve found that when building for the long term, nothing beats mineral wool insulation. 

At AE Building Systems, we work with mineral wool on many types of projects, especially ones that are working to be Passive House designs. We carry quality products for mineral wool insulation, including Rockwool Comfortboard 80 and Rockwool Comfortboard 110. Rockwool has been a great partner to the construction community for years and our AE Building Systems team is always here to help answer your questions about material choices and specific products. 

Take My Breath Away… While the Berlin song from Top Gun was a big hit in the 1980’s, in a home, we know that good air quality is vital to a healthy space. As homes have become more energy-efficient and airtight, air quality in a home is one of the top priorities. 

Why Does Air Ventilation Matter in a Home?  

Proper ventilation is like lungs in a body. Homes need proper ventilation to keep air fresh and the indoor space as healthy as possible. Opening windows doesn’t always work because the air that we allow in is not filtered, and we’re losing thermal energy we paid for with our heating and air conditioning bills. Mechanical ventilation is vital to ensure that fresh air comes in and dirty air goes back out. The air inside of a home can build up pollutants, dust, odors, moisture and more, making it a problem for anyone with asthma, lung problems, allergies, or those susceptible to disease. The proper mechanical ventilation design will help ensure that indoor spaces stay safe and healthy from day one. 

How do you ensure that your mechanical ventilation is set up properly?  

Have a plan. 

Most new construction home projects will have a mechanical design in place that should address many of these concerns. Make sure you are working with an expert who is well-versed in air quality and ventilation. Many contractors know the basics, but ask questions to find out if your hired expert has experience with strict air quality standards, and balanced systems, meaning it exhausts the same amount of air that is being brought in so the home is not artificially inflated or deflated (pressurized or depressurized) If you aren’t sure who to talk to, reach out to our team at AE Building Systems. We have a list of trusted pros.. 

Look for a ventilation plan that incorporates air quality measurements. 

There are simpler models that are intended to just run in the background day and night no matter if the occupants are home or away, which is a ‘good’ approach that works for many families. This system still requires spot exhaust fans in the bathrooms and kitchen vent hoods that are manually activated when needed.

A ‘better’ ventilation system selectively exhausts the stale air and odors from the bathrooms and the kitchen, and delivers fresh air to the bedrooms and living areas. This distribution system is a bit more involved, but it can be designed to meet code requirements for bathroom ventilation so that spot ventilation fans are eliminated, and a kitchen vent hood would only be needed with a gas range or if the occupants’ cooking involves above-average smoke and odors. This ‘better’ system requires a higher-end ERV with a boost feature that allows increasing the air exchange rate on demand, for instance when someone is using the bathroom.

By far the ‘best’ ventilation system on the market today employs an ERV that measures the air quality in the home and adjusts its mode of operation accordingly. This unit is called the Conditioning Energy Recovery Ventilator 2 (CERV2) and it is manufactured by Build Equinox in Illinois. Its air quality sensors measure carbon dioxide (CO₂) and volatile organic compounds (VOC) which together offer indications of how contaminated and or spent the air in a home is at a given moment. It uses this information to adjust its mode of operation from fresh air ventilation to filtered air recirculation and sometimes it simply shuts its blowers off to save energy. 

Instead of the passive heat exchanger core most ERV units use, the CERV2 is equipped with a small internal heatpump that allows precise control of the flow and amount of thermal energy that is recovered. 

Here are some of the features we love about the CERV2:

1. Instead of the passive heat exchanger core most ERV units use, the CERV2 is equipped with a small internal heatpump that allows precise control of the flow and amount of thermal energy that is recovered.
2. Fan selection size – You can get 6” or 8” and while 6” fans are generally used in smaller multifamily projects, 8” fans are generally used in most single-family residences greater than 2,000 ft² and homes where the elevation is 5,000 ft.   Please contact us to help with design considerations.  
3. With a properly laid out distribution system, the fully automated CERV2 provides fresh filtered air to the living areas and bedrooms of the home, and dependably removes stale air and odors from the bathrooms and kitchen. Such a system can meet the requirements of building code and eliminates the need for bathroom fans. In some municipalities, a kitchen vent hood is then only needed with a gas range or if the occupant’s cooking involves above-average smoke and odors. Please refer to your local building code. 
4. Remote wireless booster switches are used for manual activation of high air exchange (boost) mode, or wireless active circuit transmitters that are installed in bathroom lights for automatic activation of boost mode. By temporarily ramping up the fan speed and switching to air exchange mode when someone is using the bathroom, odors are removed more rapidly.
5. Geoboost provides pre-conditioning in both summer and winter and it can also help with post-heat with a hot water connection.  
6. The Warmflo duct heater can also be included for additional BTUs in the supply lines. 
7. The CERV2 uses various configurations for remote sensors and zone dampers, wireless connections, and even an I/O expansion board for more control. Let us know how we might help with your needs. 

Hans Joachim Preiss and his firm BrightSense have been designing ventilation systems for several years. Starting with generic ERV and HRV units, the first generation CERV, and now the CERV2. “The idea of knowing the quality of the air you’re breathing inside your home and having a ventilation unit that constantly adjusts its mode of operation so that a high level of air quality is maintained without wasting energy, is only offered by the CERV2 from Build Equinox. This concept is so simple yet advanced, I have not had a single client who regrets their decision to go with the CERV.” says Hans.

Conceptual simplified CERV2 system:

Sample CERV2 supply and exhaust diffuser locations and airflow volumes:

Sample layout of a CERV2 distribution system:

Learn more about CERV2 and get more product specifications HERE.

Learn What You Can

Whether you are a homeowner, the designer, a contractor, or a specialist on the project, the best thing you can do is to learn as much as possible about the plan for air quality in the home. Here are a few simple ways to educate yourself:

• See the basic specifications and product information. Click HERE for CERV2 info. 
• Consider the installation process and understand the product from start to finish of installation. Installation manuals are a great place to start to understand how a product is meant to operate. Take a look. 
• Research the manufacturer of the ventilation system. Go scope out the company directly and see what you can learn from them directly. You can learn more about Build Equinox here. 
• Sign up for Build Equinox’s newsletter. See one of their recent ones here with opt-in options at the bottom. 
• Take a look at CERV-IR’s Magic Box Mechanicals detailed specs. Click here to view. 
• Talk to an AE Building Systems team member to ask general questions. We can help point you in the right direction and help you find the answers you need. 

Your home should be a safe, healthy space. That starts with strategic mechanical ventilation that measures the air quality. When you are able to monitor the quality, you are able to work on any improvements. At AE Building Systems, we want to help you build safe, healthy spaces for yourself or your clients. Let us know how we can help you succeed on your next project!

Resource guide to up your Passive House knowledge – 

Whether you are building your own home, or you are hiring a contractor to help build your Passive House, you’ll want to get knowledgeable. The exciting thing about Passive House is that the designs are constantly evolving and getting better. There are new faces joining the movement everyday, and there’s so much to learn!

Educated Consumer

Many homeowners find that base knowledge is vital to the success of their project, especially when it comes to Passive House construction. The more educated you are, the better you can make sure your home is being constructed in the right way. Because of the lack of general knowledge in the industry, it is sometimes best to participate more or less as a quality control agent of sorts. Knowledge also gives you a base for asking the right questions to your contractor. Even more, when you know the details about your type of construction, you can advocate for specific design choices or construction techniques that you might never have considered otherwise. An educated client is a smart client. Your contractor will appreciate the insights you can bring, and you will be more satisfied with the final product.

Educated Contractor

If you are a contractor considering getting into Passive House construction, this is a no-brainer! Education in a focused niche of construction like Passive House techniques is a huge asset to your scope of work. You’ll  find yourself employing passive house concepts or approaches to any type of construction, even if the project doesn’t require strict Passive House requirements. Additionally, if you are certified, it becomes a huge selling factor for people looking for experts  that can achieve nearly any high performance building objective. You can set yourself above the rest of the pack simply by getting more education. 

If you’re looking to up your Passive House knowledge, where do you start? 

Our team has compiled a great list of resources to help you get started. Some of these resources have specific programs and even certifications, and some are simply helpful resources to stay up on the latest developments. Either way, we hope you find them helpful as you go deeper into Passive Houses.

Passive House Associations to Check-Out:

• (CPHT): Courses and accreditation exams for building professionals. 
• Passive House Institute US:  This organization is based in the United States, but offers a ton of education on their website if you’re starting off. If you want to go deeper, they also offer certifications in Passive House construction. They even offer live events and trainings throughout the year. 
• Passive House Institute:  The Passive House Institute (PHI) is an independent research institute focused on performance-based energy standards in construction. They offer certifications, in-person trainings, and a wealth of information on their website. 
• North American Passive House Network (NAPHN):  A building industry leader in education for low-energy, high-performance Passive House design and construction. They offer educational resources throughout the year, but also with their big conference each year. Don’t miss how they are rolling out a virtual element this year. 

Top Resources For Trainings/Events:

• Emu:  Emu is an accredited Training Provider with the International Passive House Institute (PHI). They are authorized to offer Certified Passive House Tradesperson 
• Local PHIUS Meetup: Look for Passive House Meetups in your local area. If you’re in Colorado, we’d love to see you at an upcoming event with this Meetup.  
• NAPHN Conference in New York: Join NAPHN for their annual conference. More info HERE. 
• PHIUS Conference:  Currently set for Fall 2020, the PHIUS conference is always full of great speakers and education! Learn more HERE. 
• Global Passive House Happy Hour:  The Passive House Accelerator has a weekly virtual happy hour with people from all over the world. You can find out the times and details HERE. They also have a great newsletter you can sign up for as well, full of quality information. 
• Love | Schack:  Love & Schack are two architects who focus on client-centered design with high performance and natural materials, and made a witty company name when Lindsey and Lindsay joined forces! They offer amazing designs, but also put on webinars and share great resources with their community. 
• Build Equinox:  Build Equinox is a great source if you love getting into the details of Passive House construction. They regularly put out new articles and updates to help the community stay on the forefront of this industry – especially related to ventilation strategies.. 
• Certified Passive Home Consultants: If you need someone to weigh in on your project, consider hiring a certified consultant to give you expert insights. See the above sites for certifications to also find certified experts.

To Stay on Top of the Passive House Movement, Consider Following our Favorite Instagram Accounts:

• @buildingsciencefightclub – Building science and construction for architects
• @emubldgscience – Empowering the construction industry through Passive House training, virtual prototyping, and standardized systems
• @risingerbuild – Builder, remodeler, and YouTuber focusing on high-performance homes
• @passivehouseschool – Source for Passive House knowledge
• @phoenixhausgj – Prefab Passive House designs and manufacturing. 
• @unbuilditpodcast – New industry podcast coming to the scene
• @greenbuildingadvisor – Information about designing, building, and remodeling high-performance homes
• @Passivehouseaccelerator – Insights from the Passive House community to design+build better buildings
• @alpenhpp – Providing high -performance products, windows, and glass
• @thermalbuck.us – High- performance window buck systems 
• @advantagewoodwork – Carpenter focusing on Passive House best practices
• @siga_north_america – SIGA, focusing on zero energy loss buildings
• @passivehouseinstituteus – Profile for PHIUS
• @buildingsciencegirl – Educator of building performance for homes
• @rockwoolna – Smart and sustainable stone wool insulation products for the construction industry.

Have you ever experienced a drafty spot in the living room? Perhaps, you have one room that just never stays warm? In our modern days, we’ve come to expect that houses simply are drafty or have cold zones. However, the truth is that we don’t have to settle for Arctic blasts inside our homes. There’s another alternative!

Passive House, or PassivHaus, is a remarkable construction strategy that allows us to build spaces that work for us, providing a naturally regulated system for heating and cooling. One major goal of a passive house plan is to reduce energy consumption required to heat a home, but it has many other positive impacts as well including healthier and quieter spaces, greater durability, and greater comfort for inhabitants. Passive House building focuses mainly on three areas: SuperInsulation, low air infiltration and minimizing thermal bridging. In a passive home, you don’t need to sleep in a parka just because your bed happens to be in a drafty corner! Pack up your parkas; there’s no need for one in a Passive House. 

History of Passive House Building

The Passive House was highly developed in Germany, but has roots in North America as well. Now a global movement, the Passive House movement became an idea after the oil embargo of 1973 in the United States. Americans realized the need to be more self-reliant in energy, and the Lo-Cal house was designed. The Lo-Cal house in 1976 was created to be highly insulated and consumed 60 percent less energy than the standard house at that time. 

In the late 1980’s the movement shifted over to Germany where Wolfgang Feist refined the passive house approacheven more. Dr. Feist eventually designed and built the first PassivHaus in 1991 with an annual heating demand of 15 kilowatt-hours per square meter of living space. Feist also founded the Passivhaus Institute (PHI) and created the Passivhaus performance standard, which is known as the highest standard for energy efficiency even to this day. Heating loads must meet 4.75 kBTU/sf/yr. Most existing and even some new homes are 40 to 70 kBTU/sf/yr. Also, airtightness must be below 0.60 ACH50. Most existing homes are 4.0 to 15.0 ACH50 and even worse. 

Passive House Institute US (PHIUS) and Passivhaus Institute (PHI) are now the two leading organizations that set standards for passive homes in North America and in Europe. PHIUS has certifications available for properties that meet their standards and also has many collaborative partnerships with other organizations to promote better energy efficiency in the construction industry.

Why Invest In Passive House/Haus?

Passive House Buildings have strict standards. While many homes meet all the requirements, some also follow the guidelines but don’t get certified (we call these Darn Good Houses around here and you can see why we coined this phrase here). Many homeowners and designers also work to retrofit existing builds along the passive haus ideas to help lower the energy load on an existing structure. There is also a retrofit standard separate from new construction. Regardless of the type of project and level of certification, there are numerous benefits to a Passive Haus building:

1. Comfort: Passive House Standards are focused on a superior level of comfort both during the cold months AND warm months. The design concepts work for both extremes of climate, including the extreme heat of the desert to the extreme cold climates. Multiple studies by passive home residents confirm these high levels of comfort year-round.
2. Quality:  Passive House designs are known for high efficiency largely due to the high levels of insulation and airtight design. Any weak spots around the home are constructed to Passive House buildings standards. Special attention is put on the windows, doors, corners, and any other angles.
3. Sustainability:  Passive House design is sustainable by nature, due to the dramatic energy savings in heating/cooling the home. They use very little primary energy, and any extra measures for building a house in the first place to these high standards pales in comparison to the amount of energy savings the house will have over the lifetime of the building. A Passive House requires as low as 10 percent of the energy used by typical Central European buildings!
4. Cost Savings:  While Passive House buildings have some extra upfront costs, they truly are an investment, rather than an expense. Any additional budget items in the original build save a homeowner thousands upon thousands in the long run in energy costs. 

Beyond The Residential Home

What began as a way to decrease the loads on residential homes, has now become a global movement for passive design at large. The applications are just as relevant for commercial designs for almost any type of space, from hospitals to schools, to commercial store buildings, offices, and more. The Passive House design principles have been adopted by architects, engineers, and contractors alike to make smarter spaces for our communities. If we can build smarter and more efficient buildings, why wouldn’t we? It’s simply the logical thing to do.

AE Building Solutions is proud to be a leader in the Passive House world, providing building envelope components and products that help designers and contractors meet Passive House Standard and certification requirements. We carry products like windows, weather/air barriers, ventilation systems, and insulation for comprehensive building construction. We’re devoted to increased thermal performance, reduced air infiltration, and reduction of thermal bridging to make more efficient homes. 

Given we are burning through our natural resources rapidly, AE exists to help make a dent. Wanting to have an impact on our children’s energy and environmental future, setting our children up for a better tomorrow, and simply doing things more energy efficiently is all a part of AE’s mission.

Looking to get involved with other Passive House construction professionals? 

• Join us at the Passive House Meetup in the Denver Area
• Join us at Emu’s Colorado Passive House Happy Hour
• Join us at the next JCRES meeting 

The focus of AE Building Systems over the years has been the building envelope. We have concentrated on this specific part of the building with the conviction that most issues related to green building start with a well designed and executed wall assembly. In fact AE has predicated its entire business on this basic idea. While most of our focus has been energy efficiency and comfort, the idea that a building should be healthy has always been assumed. Recently, a couple of events have brought this very important issue to the fore of AE’s thinking. Specifically the idea that occupant comfort is not just related to air temperature, but also the specific content of the air they breathe and the indoor air quality.

The Virtue of Health

A few months ago Jackie Burnett contacted AE, because of her interest in building a Passive House. She was moving from Vermont to Fort Collins and was searching for some land on which to build. In meeting with Jackie it became apparent that her goals of this project were slightly different than the majority of our customers. While energy efficiency and longevity were important, the healthiness of this new home was of most importance. Jackie, like many people, suffers from the debilitating effects of toxic environments. Mold, mildew, high VOC contents, all contribute to symptoms that can leave her bedridden. Jackie’s home not only needs to be free of these poisons, but needs to remain so for the life of the building. Jackie came to AE with very specific needs. She wanted factory produced wall assemblies, products that had little to no VOC content, and systems that provided a healthy indoor air quality. Jackie has helped educate the whole AE staff on the virtues of a healthy building and their effects on occupants. Fortunately AE is in a position to help and we are looking forward to continuing this journey with Jackie.

The Healthy Air Equation

Jackie Burnett feels the real effects of poor indoor air quality and came to AE primarily because of her interest in the CERV (Conditioning Energy Recovery Ventilator). Recently, AE invited Ty Newell from Build Equinox to give a presentation on the CERV. Ty specifically spoke about the benefits of good IAQ. As we build tighter and more energy efficient “a critical shift in thinking from a goal of indoor environments that are acceptable to the occupants to those that are truly healthy and productive” must take place. (Bill Bahnfleth 2013-14 ASHRAE President). We have spent many years researching and perfecting wall assemblies that are air tight, with high insulation values, but can also dry to the outside. This was the obvious solution to homes that were failing do to moisture penetration, resulting in the development of mold and decay. Not only were our construction techniques resulting in short building life cycles, they were also placing building occupants at risk. Tightening a building helps reduce the amount of VOC content allowed to infiltrate a building. Increasing insulation levels help to reduce energy loss and increase comfort. But, without a way to continuously eliminate VOC build up and manage moisture, we are setting a course for continued building failure and risking the long term health of our clients.

The goal of the CERV is to manage these these risks in an energy efficient manner. The CERV continuously monitors indoor air for both CO2 and VOC content. Through it’s interface occupants can set both levels to meet their desired comfort. Taking a hourly sample, the CERV will only bring in fresh air when one or the other of these levels is exceeded. It can’t be overstated the importance of appropriate CO2 levels. Recently, Berkley Labs conducted a study on elevated indoor CO2 levels. They discovered that contrary to previous thought, decision making impairment can start as low as 1,000 PPM of CO2, with significant impairment beginning at 2500 PPM.

The primary source of indoor CO2 is humans. With the adverse effects of CO2 becoming clear and the increased air tightness of buildings being mandated, designing an efficient mechanical fresh air system is now critical to any building plan. Likewise, with VOCs, a precise plan must be made. VOCs can range from smells produced in a home from cooking and other activities, to off gassing of building materials, furniture and even humans. Keeping these toxins at an appropriate level is key to a healthy indoor environment.

The building industry has understood for a while that keeping the humidity levels between 35 and 50% was optimal for building performance. As it it turns out is is also optimal for occupant health. Humidity levels below 25% lead to drying of the mucous membranes and chapping of the skin. Higher humidity levels increase the development of mold and fungi. The CERV maintains humidity levels at those 35 to 50% levels all year around as seen by the graph below.

A healthy building starts with good design and product selection. Making your building tight and with high insulation levels is a good start. In order to maintain the health of the building and the health of the occupants a good fresh air system is critical for the long term functionality of the building. Selecting base building materials and furnishings with low VOC content and low levels of toxins is also a critical point in providing a healthy indoor environment.

AE Building Systems is now providing a variety of mechanical fresh air products that meet the standards discussed above. We are actively researching products to round out our current offerings and expect to offer design services in the near future. By providing a complete Indoor Air Quality package, along with our other products, AE can offer an energy efficient and healthy building envelope. Contact AE Building Systems for more information.

Just last week Elon Musk announced that Tesla would be producing the next great advancement in battery storage. Until now, battery storage for Photovoltaic Systems were costly, unreliable and required a large amount of space. That has all changed with the Powerwall. For only $3500 anyone can now purchase a 10kw storage system that will allow off grid operation of a home or building. As Musk stated in his announcement, this could be as revolutionary as the cell phone and as ubiquitous as the smart phone. We will no longer need wires to bring power to the world, and we will no longer rely on fossil fuels for our power sources.

What exactly does this have to do with high performance building? Generally, we building science geeks tend to focus on ways in which we can eliminate waste and reduce the amount of energy required to operate a building. We design and construct building envelopes that reduce air infiltration, and manage our heat with high levels of insulation. Squeezing out every last BTU in our designs until we can comfortably heat with a blow dryer. These are all noble goals and once critical mass is met will help significantly reduce the amount of fossil fuels we consume. Ultimately, however, no matter how efficient we become, we are consumers. In order for a Passive building or a near Passive building to be net zero energy it must produce power. Combining the two technologies would be a powerful force that could literally convert the world to only renewable energy production.

In Musk’s presentation he pointed out several astounding facts that make the previous statement more real than we might think. Musk explained the the surface area required to power the United States completely using solar was equivalent to a square the size of the northern Texas handle and that the area of battery required to mange this production was a tiny dot in the middle of it all. The United States would need 160 million 100kw Powerpacks, (Tesla’s utility grade battery system), to transition entirely to renewable energy. While this is quite impressive there is a key variable that gets ignored in Musk’s presentation that would make this transition faster. Status quo ruled Tesla’s assumptions as it related to the worlds energy consumption. As we all know the majority of the that energy is consumed by buildings. What if we combined Tesla’s world vision with the continued proliferation of Passive House?

Passive House seeks to reduce the total required energy to run a facility by up to 90%. This type of construction is becoming more prevalent and in some cases required throughout the United States and the World. This reduction in energy consumption would make adding renewables more obtainable. Individual buildings would require significantly less PV and fewer batteries in order to operate entirely off the grid. Less money spent on the renewable side of the equation would mean more money for energy efficient strategies and materials. Combined with more aggressive governmental policies reducing carbon use, like we see in Fort Collins, flattening the Keeling Curve becomes more realistic.

AE Building Systems is proud to be part of a global movement to be better stewards of our planet. Make no mistake, that while we tout the personal benefits of building more efficient, we have a clear vision of making the world a better place. Leaving a cleaner environment for our children. By providing education and product that reduce building energy consumption we approach the problem from the opposite side of Tesla. Soon we hope to meet in the middle.

AE Building started out with the simple idea of filling a void in the building industry by providing high performance, energy efficient building products. Since that time we have expanded our reach by becoming building envelope experts, consulting with our clients on the many decisions required to develop a high performance wall assembly. We have seen a maturation in the market where owners are increasingly demanding better performance and architects and builders are responding. AE Building has responded as well. We have been ahead of the curve with many of the products and technologies that we promote and have found it necessary to provide appropriate training to many of our customers and installers. A more recent example of this type of collaboration is with our excellent installation partners Efficiency Matters. AE has always been impressed with their attention to detail and fine craftsmanship, but wanted to be sure they understood the intricacies of a Alpen window installation using SIGA air sealing products. AE partnered with Nicholus Holbus from SIGA and Riley Dennig from Alpen to develop a joint workshop. Efficiency Matters crews received hands on training in regards to the application of SIGA tapes and membranes as they relate to window installation. Riley then walked them through a best practices training on an Alpen window install as well as making appropriate adjustments to the windows for optimal operation. They finished with an Alpen factory tour. This type of training ensures that AE and Efficiency Matters can continue to service their clients in the very best way possible.

A good example of how this training helped with a customer comes from Matt Bruckner of Bruckner Construction. Matt couldn’t be happier with the products and service he received from both AE and Efficiency Matters. AE put together a wall assembly for Matt for the McNaughton residence that included air sealing, windows, and exterior insulation in an integrated package. AE also suggested that Efficiency Matters would be an excellent choice for installing the systems. When we spoke with Matt he was excited to point out how seamless each component of the system worked together and the attention to detail that Efficiency Matters displayed in installing the system. Not only does the finish product look fantastic, but we know that the owners will be pleased with the resulting comfort and energy savings.

AE is continually looking for opportunities to collaborate in this manner with owners, architects and builders. Recently we participated in the Energy Smart Contractors Expo speaking on deep energy retrofits. We are working with several architects, helping them to develop new “go to” wall assemblies. When is comes to wall assemblies we will go anywhere and speak to anyone that is interested.