Jamie Bontrager, Author at AE Building Systems

High Performance Walls and SIPs

When building an energy efficient home, High Performance wall assemblies are critical components, and can be grouped into a couple of categories: 1. Built on-site advanced wall assemblies and 2. Prefabricated walls, to include SIPs.

Note that this blog post is largely dedicated to Polyurethane SIPs.

ICFs, Insulated Concrete Forms, are a good option and are manufactured by several companies. Faswall and Nexcem have an interesting woodchip product. There are pros and cons for ICFs, and it is important to understand both.

Advanced Wall Assemblies

The goal is to improve the wall construction of conventional, stick built homes with advanced wall assemblies to include double stud, stagger stud or continuous insulation walls.

Double stud walls consist of two stud-framed walls set up next to each other to form an extra thick thermally broken wall cavity that can be filled with insulation. Because the interior and exterior framing are separated by insulation, thermal bridging is reduced or, ideally, eliminated.

Stagger stud walls use top and bottom plates that are normally 2×6 (5.5”) – 2×12 (11.25″). Vertical 2 x 4 studs are then staggered alternately on each side of the plates. This is a good option for extra insulation, reduced thermal bridging and sound-proofing of spaces as well.

Another option is standard construction with a Continuous Insulation (CI) layer. In CI, builders add a continuous layer of insulation across the exterior of all structural members to reduce or eliminate thermal bridges, except for fasteners and service openings. Insulation is installed generally on the exterior of the building and is an integral part of the building envelope. Comfortboard 80 is an excellent vapor open product that can be used for a CI approach. Mineral Wool is generally favored, as foam tends to have low perm ratings and generally the desire is for our walls to dry to the outside. Often folks using a CI approach do not use enough insulation to move the dew point outside of the wall assembly. It is critical to have a vapor open approach if the dew point falls within the stud cavity.

Prefabricated Walls

Prefabricated walls are built in a factory, transported to the building site and craned into place. Manufacturers of these types of walls include:

Phoenix Haus, which designs and produces open sourced housing templates for walls that save energy, provide better insulation and allow homes to be more efficient with or without solar energy.

Build SMART simplifies the process of building a high-performance, energy-efficient structure with factory-manufactured modular components. Continuously insulated panels come with pre-installed, energy-efficient windows and doors and are delivered to the building site.

SIPs – Structural Insulated Panels. There are several types of SIPs out there. Generally, the difference between SIPs is the insulation. Most are made with OSB (oriented strand board) skins, but some SIPs have different skins to include metal or MgO (Magnesium Oxide) skins. Most often, the insulation is EPS or Polyurethane. However, there are some that are made with mineral wool, PolyIso (Polyisocyanurate) or XPS (extruded polystyrene).

Some SIPs are not considered structural (e.g. most metal SIPs), and they might be referred to as Sandwich Insulated Panels.

SIP panels made of EPS, XPS or PolyIso are glued together generally with Polyurethane adhesive. SIPs made with Polyurethane foam are adhered together with the foam itself creating a tremendous bond and a very strong wall panel solution.

Thermocore SIPS are made with polyurethane insulation core with interior and exterior skins of OSB. Panels are precisely and custom manufactured to the architectural drawings. Included in the SIPs are door and window bucks, headers, sub facia and electrical conduit boxes. Also, beam pockets and additional structure like 2x, LVL or steel posts can be built into the panels.

Construction with Thermocore SIPs is quicker than framed homes. The time from foundation to dried-in is significantly reduced. Labor costs are lower, which is ideal in places where available labor is scarce, costly, unreliable or poor quality. Thermocore SIPs are stronger than framed walls, with lower thermal bridging.

Thermocore SIPS often have higher material cost, the electrical requires pre-planning and can be considered less environmentally friendly due to foam, which is a petrochemical product.

The thermal performance values of SIPs and lower labor costs often make up for the initial cost and planning. SIPs help to achieve a more air tight building as well. In the Passive House and Zero Energy industry, where energy efficiency, comfort and clean air are the goals, Thermocore SIPs are an optional building solution.

For more information on SIPS, call us at 720-287-4290.

Sources: U.S. Department of Energy, Greenbuildingadvisor.com, Thermocore.com

Quality Indoor Air with the Help of ERVs

Because High Performance buildings, like Passive Haus homes, are so air tight, the quality of the air within is a critical consideration. Whether we are at home, at work or in other public buildings, we are exposed to many indoor air pollutants. These pollutants can cause minor health issues such as headaches, eye irritation, allergies and fatigue, or major ones like asthma and different forms of cancer.
Gases such as carbon monoxide and nitrogen dioxide, known as combustion pollutants, originate from burning materials or improperly vented fuel-burning appliances such as space heaters, wood stoves, gas stoves, water heaters, dryers and fireplaces. Carbon monoxide cannot be easily detected, as it is colorless, odorless and tasteless. It’s a toxic gas which causes headaches, dizziness, weakness, and nausea; and at high levels it can be deadly, hindering oxygen delivery throughout the body. Nitrogen dioxide, another colorless and odorless gas, causes eye, nose and throat irritation, shortness of breath, and increased risk for respiratory infections. Cooking with natural gas emits high levels of Nitrogen dioxide.
Many high-performance homes are all electric and there is no “burning” of hydrocarbon products. However, other forms of air pollutants include volatile organic compounds (VOCs) which are defined as invisible toxic gas emissions from solid and liquid sources found inside our homes. These include paints, cleaning supplies, pesticides, building materials and office supplies such printers, glues, and permanent markers. Even a new sofa will off-gas VOCs. Levels of certain VOCs can be 10 times higher indoors than outdoors. Like other indoor air pollutants, VOCs can cause health problems, specifically respiratory and allergy issues in children.

It is crucial to combat all these indoor air toxins, but is there a way to have outdoor-quality air indoors?

We can improve our indoor air by:
1. Removing the source of the toxins in our homes and offices: not smoking indoors, by purchasing products that are less toxic, such as those made with natural ingredients, and using them according to the instructions.
2. Reducing the amount of air pollutants and VOCs indoors by cleaning the air with filtration. Electronic air cleaners and ion generators are effective in removing some airborne particles, but not gases or odors, and many of them can produce ozone that may irritate the lungs. Ion generators may remove small particles (tobacco smoke) from the indoor air.
3. Providing adequate ventilation through a system that brings fresh air into the home or building

Types of Ventilation Systems
1. Exhaust ventilation system: This system depressurizes the home by exhausting air from the house while make-up air infiltrates through leaks in the building shell and through intentional, passive vents. Exhaust ventilation is best for cold climates. In warmer climates with humid summers, depressurization can bring moist air into building wall cavities and cause moisture damage. It can also bring in pollutants we are trying to remove: radon and molds from a crawlspace, dust from attics, fumes from attached garages and flue gas from a fireplace or fossil fuel-fire water heater and furnace.

2. Supply ventilation system: A supply ventilation system uses a fan to pressurize our home, bringing outside air into the building while air leaks out of the building through holes, bath and range fan ducts and intentional vents. Drawbacks are they do not remove moisture from the make-up air before it enters the house and may contribute to higher heating and cooling costs. If the interior air is humid enough, the moisture in the air can condense and rest in the attic or cold parts of the exterior wall, causing mold, mildew and decay. This system is best for hot or mixed climates.

3. Balanced ventilation system: This system does not pressurize or depressurize our homes. Instead, it introduces and exhausts approximately equal quantities of fresh outside air and polluted inside air. A balanced system is appropriate for all climates but does not remove moisture from the makeup air before it enters the house. This can increase heating and cooling costs.

A Better Solution: Energy Recovery Ventilation Systems
The most efficient kind of ventilation systems are energy recovery ventilation systems, as they provide a controlled way of ventilating a home while minimizing energy loss. They reduce the costs of heating ventilated air in the winter by transferring heat from the warm inside exhaust air to the fresh (but cold) outside supply air. In the summer, the inside air cools the warmer supply air to reduce cooling costs. There are 2 types: Energy Recovery Ventilators (ERV) and Heat Recovery (or enthalpy-recovery) Ventilators (HRV).
Both types include a heat exchanger, one or more fans to push air through the machine, and controls. The main difference between a heat-recovery and an energy-recovery ventilator is the way the heat exchanger works. With an energy-recovery ventilator, the heat exchanger transfers a certain amount of water vapor along with heat energy, while a heat-recovery ventilator only transfers heat.
Because an energy-recovery ventilator transfers some of the moisture from the exhaust air to the usually less humid incoming winter air, the humidity of the house air stays more constant. This also keeps the heat exchanger core warmer, minimizing problems with freezing.
In the summer, an energy-recovery ventilator may help to control humidity in the house by transferring some of the water vapor in the incoming air to the theoretically drier air that’s leaving the house. If you use an air conditioner, an energy-recovery ventilator generally offers better humidity control than a heat-recovery system. Most energy recovery ventilation systems can recover about 70% to 80% of the energy in the exiting air and deliver that energy to the incoming air. However, they are most cost-effective in climates with extreme winters or summers, and where fuel costs are high. In mild climates, the cost of the additional electricity consumed by the system fans may exceed the energy savings from not having to condition the supply air.
There are some drawbacks: Energy recovery ventilation systems usually cost more to install and maintain than other ventilation systems. Also, energy recovery ventilation systems operated in cold climates must have devices to help prevent freezing and frost formation. Very cold supply air can cause frost formation in the heat exchanger, which can damage it. Frost buildup also reduces ventilation effectiveness.
However, the benefits of ERVs far outweigh the negatives. Clean, fresh indoor air is a commodity worth the investment, and the health of our families depends on it.

For more information about ERVs, call us at 720.287.4290
Source: ultimateair.com

SIGA Majrex: A Skin Like the Cactus

What can we learn from the cactus related to building science? The cactus “skin” has essentially two perm ratings. The cactus absorbs vapor through its skin at night, and in the daytime when temperatures rise, that same skin prevents the moisture from escaping. The skin of the cactus allows moisture to migrate inward, but not outward.
SIGA has learned the answer to keeping walls dry by incorporating the unique characteristic of the skin of the cactus to collect and store water. In our buildings, we want the opposite to happen — prevent moisture from getting into our walls and allow it to migrate out. SIGA’s new product Majrex does just that.

While a cactus needs water to survive, our walls do not. In fact, moisture in our walls has the opposite impact — effectively “killing” our walls instead of nurturing them. So, the goal is the reverse of the cactus.
Humidity/moisture is higher inside our buildings due to such activities as cooking, showering and many other sources, even breathing. That moisture gets into our walls through a couple mechanisms, including air infiltration. With air infiltration, air and the moisture it carries travels from the interior of the building into the walls. That moisture within the air then condenses on cold surfaces in the interior of the walls — like a “sweaty” glass of ice water on a humid summer day. While it is best to keep the air out of our walls in the first place, some air will get in regardless carrying moisture with it.

At the point we have condensation in our walls, we absolutely need that moisture to dry or migrate out of the walls. Moisture in our walls causes mold, mildew and dry rot. In a typical home, if we were to add up all the cracks in the walls, corners and around the windows and doors, we have a hole equal to a 3-foot by 3-foot window open 24 hours every day of the year. Not only does this make us cold, but it also empties our pockets. Most importantly, it enables moisture to get into our walls with air as its transport mechanism.

SIGA patented its unique, one directional moisture transport and named it Hygrobrid technology. With this technology, SIGA developed Majrex, a “smart” interior membrane. Majrex has two different perm ratings. The perm rating from interior of the building to the interior of the walls is less than 0.097. In the other direction, from the interior of the wall to the interior of the building, the perm rating is greater than or equal to 4.25. Unlike other “smart” membranes that react to humidity and become more permeable to moisture, Majrex is essentially vapor open one way and nearly vapor closed the other. Combined with the SIGA Majvest air and weather barrier on the exterior with its 68-perm rating, we can effectively keep air and moisture out of our walls and effectively enable our walls to dry to the interior or to the exterior.

Majrex offers the benefits of:
1. Making our walls airtight so air and moisture cannot get in.
2. Making sure walls are vapor open, enabling moisture to migrate out of the walls.

Unfortunately, we often hear from building practitioners that walls need to breathe, and there is a very important distinction we would like to make. We do not want air going into our walls, because that very air is the culprit which brings moisture into our walls. We do not want them to “breathe.” Instead, we want them to be vapor open.

Simply put, Majrex is a directional membrane which allows moisture out of our walls and prevents it from coming in. Thanks to the cactus, SIGA has learned the secret to keeping our walls dry.

For more information or to order SIGA Majrex, call us at 720.287.4290

Source: sigacover.com

Fresh Air Ventilation & Monitoring

Fresh air is a commodity that everyone needs and wants. Who doesn’t like to breathe fresh air? Generally, the best source of fresh air is the outdoors. But since most of us don’t live outside, we can still supply fresh air to our homes by opening windows and doors. However, we all know it’s neither cost-efficient nor wise to leave our windows and doors open during the cold winter or hot summer.

Many older homes are leaky enough that fresh air enters through all tiny cracks and holes in the walls and around the windows and doors. With high-performance homes, the foundation is to build it air-tight and add ventilation. The catch phrase is, “build it tight and ventilate right.” But how exactly do we “ventilate right” in an airtight home when our objective is to keep cold air out in the winter and cool air in in the summer?

We must mechanically bring in fresh air. The Build Equinox CERV system does just that. The CERV recirculates air, brings fresh air in and removes stale air while offering both heat recovery and air filtration. Put simply, the CERV makes sure you have fresh, filtered air and keeps heat where it belongs, in or out based on the setting on the unit.

Designed with sensors to detect VOCs (Volatile Organic Compounds) and CO2, the CERV will “smell” the air and put itself into circulation or ventilation mode appropriately based on the sensor readings. The VOC and CO2 levels drive the demand of the unit based on the thresholds the owner programs on the unit.

A CERV returns air from rooms such as the baths, the kitchen and possibly other rooms that might have more “smells” or humidity such as workout rooms, laundry rooms, etc. It brings that air back to the unit to either simply filter/recirculate it or to replace it with fresh air from outdoors while exchanging the heat that is in the air. In the winter, it keeps heat in and in the summer it reverses the process and keep heat out of the building.

One of the more unique features of the CERV is that it uses a heat-pump to move heat to the incoming or exiting air stream. While it is not meant as a primary source of heating or cooling, the CERV actually provides a small amount of heating or cooling capacity.

Components of the CERV System:

Heat-Pump Module (A)
Module A of the unit heats, cools, dehumidifies and exchanges energy between incoming incoming(fresh) and exiting(stale) air streams, with no low temperature operation restriction. Most H/ERV’s require some kind of anti-freeze function or capability. This is not necessary with the CERV.

Fresh Air Control Module (B)
Module B of the CERV houses the electronics, integrated pollutant sensors (CO2, VOC, temperature and humidity) and damper, and this is where the CERV intelligently monitors air quality and activates fresh air ventilation. When fresh air is not needed, recirculation adds heating/cooling to unify comfort and indoor air quality. Also, the Fresh Air Control Module is fully insulated with no thermal bridges. It has a very user-friendly color touch screen controller with large print, easy to navigate control and status screens. The controller can also be placed anywhere in the house. In addition, it has an option to connect to the Internet, through the CERV-ICE Online Gateway, making it possible to control the system directly from a smart phone, tablet or computer.

Inline ECM Supply & Exhaust Fans

These are variable-speed ECM fans which balance air flow efficiently, supplying fresh air to the occupants and exhausting polluted air from house.

Inline Filter Boxes
These boxes remove air contaminants from incoming air to the home and are placed where fresh air enters. The CERV uses common filter sizes which can be purchased from several sources.

An important fact to consider in fresh air ventilation is the natural atmosphere CO2 (carbon dioxide) level of outdoor fresh air is 400 ppm (parts per million CO2). At more than 900ppm, a person’s mental performance, sleep quality, and productivity decreases. Currently, the indoor air quality ASHRAE standard for newly constructed homes is 1100ppm! If that is the standard, then we can clearly see why our air quality is a problem (source: https://ehp.niehs.nih.gov/1104789/). The good news is the current average indoor air quality level for homes in the CERV community is 686ppm.

Also note that some homes integrate various accessories that accomplish various objectives. For example, booster switches can be added to bathrooms and kitchens to help evacuate humidity and pollutants from those spaces. In addition, there are accessories that either help to pre-condition the air as it comes into the CERV from outside or to heat the air after it leaves the CERV. Please contact us for more information on these accessories.

In summary, as part of the high-performance home or any home for that matter, the Build Equinox CERV system makes good sense:

Fresh, clean air for the family
Recovers heat/doesn’t lose it
Provides health benefits of reduced CO2 levels (improved brain function, sleep quality and productivity), lowered pollutant/contaminant levels of things we bring into our home (i.e. off-gassing of new items we purchase, paint fumes, as well as pollutants created within the home, such as cooking odors, bathroom and laundry room odors or pet odors).

If fresher, cleaner air in our homes is the goal, then a Build Equinox CERV home makes next-to-outdoor fresh air in a home quite achievable.

For more information about the Build Equinox CERV, call us at 720.287.4290 or visit our website https://aebuildingsystems.com/product/build-equinox-cerv/.

Source: buildequinox.com

High-Performance Windows

If eyes are the windows of the soul, then windows are the eyes of the energy-efficient home.

Generally, windows are the weak link in the walls of a home. “I love putting plastic on my windows to keep cold air out and warm air in,” said no one ever. That is why considering the brand and style of the windows in a home is just as important as deciding insulation and exterior materials.

The goal is comfort and operational cost saving, and the goal for builders and architects is providing both.

High performance windows are necessary in keeping with Passive Haus standards of efficiency: design, minimal thermal bridging, air tight, super insulated, optimized glazing, energy recovery ventilation and passive gains.

So we have learned that code built homes often lose 20 to 40% of the heat in the home through air infiltration, and windows and doors are a significant source of this heat loss.

To better grasp just how significant, imagine the volume of a basketball as our measure of air infiltration. According to the National Fenestration Ratings Council (NFRC), the maximum allowable air infiltration in a window, with the outside wind at 25 mph, is 0.3 CFM (cubic feet of air)/sq. ft. Air infiltration for a 10 sq. ft. standard window at the allowable maximum is 3.0 CFM or 11.4 basketballs per minute. At sixty minutes, one window allows in 684 basketballs per hour.

If you have (30) 10 sq. ft. windows, that equals 342 basketballs per minute or 20,520 basketballs per hour. That is a substantial amount of heat loss.

How do we reduce the basketballs?

Consider installing Alpen or Advantage Woodwork High-Performance windows. With a high-performance window, air infiltration at a 25 mph wind is <= 0.01 – 0.05 CFM (cubic feet of air). A 10 sq. ft. high performance window is at 0.10 CFM or .38 basketballs per minute or 22.8 basketballs per hour.

Therefore, (30) 10 sq. ft. windows equals 11.4 basketballs per minute or 684 basketballs per hour. We just went from 20,520 to 684 basketballs per hour. To summarize, that’s approximately a 97% reduction of air infiltration from what the NFRC says is acceptable.

The bad news is loss of air through a structure’s windows is like opening the windows and tossing our hard-earned money out of them. The good news is high performance windows fixes that problem.

The overall quality and performance of windows like Alpen or Advantage High-Performance windows is also superior. What makes these windows even more unique are their individual components, designed to combat heat losses (winter) and gains (summer):

Frames – High performance windows have durable, low conductivity frames which generally include insulation. These frames offer better thermal performance. The R-value of most standard frames is r-2 to r-3.5. High performance window frames are r-4 and up to r-7, 8, and 9.
Seals – High performance windows generally have multiple seals, which promote not only weather tight but also air tight seals.
Glazing – IGUs (insulating glass units). Glazing can have double, triple and even quad glass. High performance IGUs have special coatings that high performance window manufacturers leverage to optimize heat gain from the sun in colder months and reduce heat gain and over-heating in the warmer months.
Spacers – Depending on the material used, the spacers in between the IGUs can help increase the interior surface temperature of a window up to 15 degrees. For example, a galvanized steel spacer in a fixed high profile Alpen 525 window is rated R-5.9, whereas a stainless-steel spacer in a fixed high profile Alpen 625 window is R-6.7. Also, high performance window spacers reduce condensation on the edge of the glass (which reduces opportunity for mold and rot) and increases the inside glass surface temperatures, therefore improving comfort.
Gas – There is “gas between the glass,” as it is denser than air and a reliable barrier to heat loss. Argon or Krypton gases are often used. Argon is much less costly, but Krypton increases performance and is often used in Passive House projects.

While ROI (return on investment) is important, comfort and unnecessary energy use are the primary reasons people pursue high performance windows.

High-Performance Windows help create high performance homes which conserve energy for future generations. We are “burning” through our energy resources (coal and oil) rapidly. Why not own a comfortable, energy efficient home that is also super quiet and will likely last much longer than your neighbor’s home? And … let’s conserve our resources for future generations.

Please do not hesitate to call us at 720.287.4290 to learn more.

Mineral Wool Insulation: The Naked Truth

Let’s face it. Life is hard.
Sometimes, pressures of work, family and bills can kick us in the teeth. And some days, we’re counting down the minutes to get home, kick off our shoes and chill. Maybe relax to some music or zone out with some Netflix. Better still, remove the confines of the day by removing our clothes – naked with no cares.

Reality, though, comes in the form of an uncomfortable and unhealthy home, as well as peeping Toms and unexpected visits from the in-laws. Just because you can relax in the raw, doesn’t mean you should!

As architects and builders, you may not be able give your clients peace of mind about walking around naked, but you can give them the comfortable sanctuary they crave in a cost-efficient home with clean air and ideal temperatures.

One excellent way to do just that is with mineral wool insulation, a building product made of rock that is heated and spun like cotton candy to create fibers, which are then put into batts and boards. It can be used in new construction or added to existing structures.

Environmentally friendly, it is composed of 85 percent recycled slag from the steel processing industry, and 15 percent raw basalt. Also, EPA testing confirms allergens and toxins are virtually non-existent.

That’s a major plus for all but especially for home owners with children.

Consider these additional, exceptional benefits of using mineral wool insulation:

Fire Resistance

The temperature range for house fires is 1200-1400 degrees F. Mineral wool insulation melts at 2150 degrees F. This means it will not catch fire. Because it is non-combustible, it doesn’t contribute to nor will it spread a fire. In addition, when heated it will not release toxic gases. Simply put, rock doesn’t burn. Designed to maintain its integrity when exposed to flames, mineral wool allows for escape in the event of a fire. Safety should be your number one concern for a client.

Sound Reduction

Mineral wool is an excellent acoustic insulation, because rock is a natural sound barrier. Due to its unique, non-directional structure, mineral wool is denser than conventional insulation and helps to absorb and minimize sound. Owners of concert halls and playhouses find it extremely effective for keeping sound within their buildings. On a smaller scale, your client will appreciate mineral wool keeping sound out for a quieter home.

Rot Resistance

Mineral wool insulation is permeable, allowing water and vapors to escape. Also, it is somewhat water repellent. And because mineral wool has no food source, it cannot grow mildew, mold or any bacteria. This is good news, not only for those with allergies and health conditions but also for you, the builder or architect, because it helps prevent lawsuits due to wall construction failure. Vapor open assemblies, especially to the exterior, present fewer risks.

Longevity

Mineral wool insulation does not shrink, change shape or crumble – despite temperature changes or humidity. It is maintenance-free and needs no replacement.

Mineral wool perhaps is most celebrated for its thermal properties. Because it contains tiny pockets of air trapped within its physical structure, mineral wool provides extraordinary insulation, creating the down blanket for homes in cooler climates and keeping heat out of homes in warmer climates. The obvious benefit is a reduction of heating/cooling costs. Reduction in energy use plus lifelong durability equals savings in your clients’ pockets over the long-run.

Sustainability

Recycled slag and raw basalt is plentiful, and mineral wool is recyclable. Therefore, resources aren’t drained in the production of mineral wool insulation.

Also, the energy saved from the installation of mineral wood insulation far surpasses the energy spent for its production. The money spent is minimal when compared to the long-term benefits.

The above are all benefits for your client, but there are some serious benefits to you as well. When it comes to new construction and existing buildings, your reputation and business are on the line. Any faulty building product or choice of building assembly can put your insurance premiums at risk. As building codes become more stringent, and wall assemblies become more complex, mineral wool insulation reduces your liability.

Mineral wool insulation is a deal maker, not a deal breaker.

While your clients might or might not enjoy their home naked, you can have peace of mind knowing you’re providing them the comfort to do so.

For more information, contact AE Building Systems.
Source: Roxul.com