Performance versus Prescriptive Compliance for Meeting Energy Codes

During some recent travels to work with builders, I spent time with a builder who was in the process of constructing walls and building envelopes with very little R value. These were thermal mass walls but with little R value. The builder was meeting the state energy building code through the performance path, which allows for more design freedom but involves more complex energy simulations and tradeoffs between systems, by using a highly engineered, very sophisticated, very expensive, high efficiency heating and air conditioning system.

The building when it’s completed will meet the code and the intent of the code which is to reduce energy consumption.  However, the weakness of this approach is that the equipment which is being used to meet the energy reduction goal codes will eventually wear out.  When that time comes, the owners of the building will be able to replace this high end equipment with a less expensive option since they are not under the jurisdiction or ‘watch’ of the building inspectors. This will decrease the energy efficiency of the building and possibly compromise its building code compliance.

This is one of the good things about the prescriptive path to the building code – that the elements that we choose, when properly installed, will meet the code and goals of energy reduction for the long term.  Things like thermal insulation when installed during the initial construction will always be in place, will always work and will never wear out. It will continue to perform over the life of the structure.

So while it is good to have options, remember not all options will give you the desired result over the life of the structure and that is worrisome.

 

Green Thought Leader Ted Winslow, brand product manager, CertainTeed Insulation

While at Greenbuild 2014, we asked our technical thought leaders the following question:

What is the most compelling thing happening in your universe with regard to sustainability? Ted Winslow, Brand Product Manager – Building Science, Systems & Technical Marketing, Insulation

???????????????????????????????The most compelling thing for me in regards to sustainability is seeing the evolution of how people are thinking of sustainability and energy efficiency. It is not just a one-stop solution and it is not about specific products. They want to have a holistic, systems approach to solving problems and want to know and understand how systems will impact the habitat as a whole. For example, if you increase the insulation in a building and make it tighter, how does that impact other things like moisture management? People are starting to realize that no matter how tight or impenetrable you build a building – moisture, for instance, will still potentially find a way in and what will need to be done to resolve the problem?

When you are dealing with a systems approach, each system created will be different depending on the needs for the structure. The possibilities are endless.

 

What Ferrari Knows Can Help With Insulating Homes to Reduce Utility Bills

ferrari_192319It makes sense to “lightweight” automobiles, even though it costs more to use premium materials such as aluminum or magnesium than to use steel. The general rule of thumb in the auto industry is that you save about seven percent fuel economy for every 10 percent vehicle weight that you reduce. Reducing vehicle weight impacts almost every other attribute in a positive manner:

  • it burns less fuel,
  • lowers emissions into the atmosphere,
  • accelerates and brakes better,
  • provides less “wear and tear” on load bearing parts in the suspension and brake systems and,
  • is more nimble in handling.

 The aluminum alloys in the automobile industry perform equal or better to steel in dent resistance. Finally, pound for pound, aluminum absorbs twice the crash energy as steel, helping the all-aluminum Audi A8 achieve 5-star crash performance levels.

 Despite this, mainstream automakers continue to address fuel economy issues by improving powertrains, shrinking vehicle size, or a host of other band-aid fixes. A lighter weight vehicle is more efficient (efficiency improvement per unit cost) than most of these other approaches and it improves the performance of these other approaches in the process!

 Traditionally, it was high price tag vehicles (Audi, Ferrari, etc.) that were made from lightweight materials. Later this year, the 2015 Ford F-150 will launch with an all-aluminum body structure. The F-150 is one of the highest production volume vehicles in the world, so this is a game changer not just for Ford, but for the global auto industry. For the above-cited performance reasons, Ford wants you to equate an aluminum F-150 with other aluminum vehicles like the Space Shuttle or the battle-tested Army Humvee, not a soda can.

 So what does this have to do with insulation? We often hear homeowners being urged to switch to more efficient light bulbs, windows, doors, appliances, etc. to address utility bills. Yet millions of homes are under insulated.

 Like vehicle weight, insulation in a house is not very visible or exciting – at least not in the same way that a new stainless steel Energy Star refrigerator might be. Yet, like vehicle weight, improving insulation in a house is one of the smartest things you can do to lower your operating costs. Adding insulation helps improve the performance of things like high-efficiency HVAC equipment/systems, new appliances, or windows that are touted for their energy saving potential.

 We should all learn a lesson from the auto industry: it may not be as cool as an 8 speed transmission (new windows), but reducing vehicle weight (adding home insulation) is the smart move to make before you invest in other energy savers.

 

Thermal Control in Building Envelopes

Like so many things we encounter in our lives when it comes to thermal comfort in a building, it is not a one-size-fits-all scenario.  That is why it is so important to understand the thermal performance of materials but also their water vapor and air resistance properties and how they will interact in the wall assembly.

Whether specifying materials for a new construction or for a renovation it is important to have a thorough understanding of how all the components in a wall assembly will play together to get the desired outcomes for the building.

Indoor comfort is critical for human health and performance and so starting with a space that has been designed for optimal thermal performance is crucial.

Join me on Tuesday, June 3 at noon for a deep dive into Thermal Control in Building Envelopes.  After this 90 minute free webinar you will be able to:

  • Describe the three modes of heat transfer
  • Understand the thermal properties of building materials
  • Describe how to calculate the thermal performance of insulated wall assemblies
  • Describe how to insulate different types of wall assemblies
  • Describe ways to increase the thermal performance and moisture durability of roofing assemblies
  • Understand the thermal performance attributes of fenestration products – windows, curtain walls, and doors
  • Understand how thermal control in building envelopes can help earn points in the LEED rating systems

This course is GBCI approved and AIA approved for 1.5 LU.  Remember to bring your questions!

 

Don’t Confuse Product R-value with Assembly R-value

Martin Holliday

Martin Holliday

In his Blog, Musings of an Energy Nerd , in the Green Building Advisor Martin Holliday, who has been in the industry for a very long time, revisits an old topic regarding the performance claims of a certain type of insulation that we call bubble wrap. The performance claims are greatly misunderstood by most people due to the ignorance of even semi-professionals to the specifics upon which these claims are based.

The bubble wrap claim of an R-value of 8 is usually based upon its performance in an assembly not as a material by itself. They do not usually describe the assembly in which this rating is achieved when they state that performance. These products have a radiant barrier component to them and if you attend my webinars where we discuss heat flow, air flow and moisture flow – this is one of three modes of heat flow – you know that radiant barriers only work when installed adjacent to an air space. When you look at a project where they say that the product has a R-value of 8 they may have failed to mention that it was installed over spacers over a 2 inch air space when it was tested. You may not have that same scenario in your assembly.

In his article, Martin provides examples of claims that have been proven false. What was insightful to me regarding these claims is that the false claims are being repeated or made by the big box retailers who carry significant weight with consumers and DIYers. This is problematic because claims being made by a large influencer means consumers are being misled and installing a product that they think is an R-8 material when it is really an R-1 material. When their energy bills skyrocket, they are forced to redo the work and pay again to make it right.

The manufacturers have been held accountable for false claims, but who is monitoring or holding accountable, outside of Martin, when false claims or misleading information is being given to consumers at a retailer?

That is one of the reasons that using a professional contractor or installer is money well spent.

IBS Insights: Keeping Moisture out of Walls

KellyWarrenKelly Warren, CertainTeed Insulation Product Manager, participated in a live Q&A session at the International Builders’ Show. Here’s a recap of the discussion:

Q: Are there new approaches builders can use to reduce the liability of moisture and mold in wall cavities?

Yes, one of the main concerns we hear from builders is how to keep moisture out of your walls. And that’s what our new product SMARTBATT does. It is a kraft-faced fiberglass batt insulation that has an integrated smart vapor retarder — which offers additional, enhanced drying capabilities in the wall cavity. In the summer, when it’s warm, moisture tries to get into your house. When it’s winter and it’s cold outside moisture tries to escape. The smart vapor technology that is incorporated into SMARTBATT opens and closes in the right areas and keeps moisture out. And, it rounds out the complete equation when it comes to comfort — thermal efficiency, air tightness, moisture management, and acoustics.

 

The 12 Months of Homebuilding by CertainTeed

140ja0hIn the first month of homebuilding, my true love gave to me, a piece of land overlooking a scenic ravine.

In the second month of homebuilding, my true love gave to me, an awesome set of architect house plan drawings.

In the third month of homebuilding, my true love gave to me, a Form-A-Drain™ 3-in-1 Foundation footing system for drainage ease.

In the fourth month of homebuilding, my true love gave to me, a high quality, two-story wood framed home built to please.

In the fifth month of homebuilding, my true love gave to me, CertaWrap™ weather-resistant barrier and Cedar Impressions® Polymer Shake Siding in ivy green.

In the sixth month of homebuilding, my true love gave to me, thermally efficient Optima® blown-in wall insulation and Air Renew™ drywall to rid me of those VOCs.

In the seventh month of homebuilding, my true love gave to me, Ecophon® Focus Ds acoustic ceiling tiles for my media room and a 70-inch big screen TV.

In the eighth month of homebuilding, my true love gave to me, a well-insulated attic filled with InsuSafe® SP.

In the ninth month of homebuilding, my true love gave to me, a roof featuring Landmark Solaris™ solar reflective shingles complemented with Apollo Solar Roofing® to make my own energy;

In the 10th month of homebuilding, my true love gave to me, an EverNew® LT Deck and a yard surrounded by a Chesterfield Vinyl Fence for privacy.

In the 11th month of homebuilding, my true love gave to me;  Restoration Millwork Trim® to finish our dream; an EverNew LT Deck and a yard surrounded by a Chesterfield Vinyl Fencefor privacy; a roof featuring Landmark Solaris solar reflective shingles and complemented with Apollo Solar Roofing to make my own energy; a well-insulated attic filled with InsuSafe SP; Ecophon Focus D acoustic ceiling tiles for my media room and a 70-inch big screen TV; thermally efficient Optima blown-in wall insulation and Air Renew drywall to rid me of those VOC’s; CertaWrap weather-resistant barrier and Cedar Impressions Polymer Shake Siding in ivy green; a high quality, two-story wood framed home built to please; a Form-A-Drain 3-in-1 Foundation footing system for drainage ease; an awesome set of architect house plan drawings; and a piece of land overlooking a scenic ravine.

In the 12th month of homebuilding, my true love gave to me:  the keys to a brand new dream home built with CertainTeed….

 Happy Holidays from all of your friends at CertainTeed!

 

 

 

Wall Assemblies for Maximum Efficiency: How Many Layers is Too Many?

SimplexOPTIMABuilding professionals spend a lot of time dealing with production construction which has dialed in efficiencies and productivity to provide the maximum assembly for the cost per square foot.  The reality is in standard construction you build things in five or six layers. This is the standard in terms of building a wall system more efficiently and we have gotten it down to a science.  Generally a six layer home will give you a solid, energy efficient, comfortable home.

Occasionally, I work with builders on projects that remind me of possibilities beyond what is the status quo.  I recently had an opportunity to work with a builder who was building a custom home whose wall systems had 13 layers.  This wall had so much redundancy and robustness built into it that I just had to ask for a chance to visit the project and see this masterpiece being built.

This was the homeowner’s instruction: They wanted a thick wall, they wanted a silent wall, they wanted a highly efficient wall for them to own.  That’s one of the key’s to this discussion- the owner is focused on what comes afterwards- not what happened before. To achieve this goal the builder is employing a combination of traditional masonry materials and cutting edge products and systems.   

In a similar fashion, a project that CertainTeed has been involved with at the Navy Yard in Philadelphia with Penn State achieves a similar goal but in a lighter and perhaps less massive assembly – to create a highly efficient wall system that can provide comfort, improve indoor air quality, better acoustics but, and here’s the rub- to still be affordable by more typical consumers.  This was done by using a 2 x 8 construction – providing a deeper wall cavity – A Blown-in-Blanket Insulation System, Weather Resistant Barrier, a Smart Vapor Retarder and Air Barrier System, a Wallboard Solution, Rigid Insulation on exterior and Insulated Vinyl Siding. This created an R30.5 exterior wall.

In both homes, products were used to address acoustics, indoor air quality and moisture control.  Do you need 13 layers?  Probably not but the pressure is certainly going to be on what layers remain to do more than they have in the past.

Thoughts?

 

Don’t Stop at the Surface with Moisture and Mold Damage

1316551358_254450912_4-Residential-and-commercial-Flood-Water-Damage-services-free-est-8888110187-ServicesMold Awareness Month Tip #2: When you see signs of moisture damage either on the exterior or interior you can’t just address this at the surface.  You have to keep digging until you get to dry materials.  If that means tearing out the drywall and the insulation until you get to something dry, so be it. You can’t just fix the surface because it was wet. If you have to replace materials following moisture damage consider using a mold and moisture resistant drywall and a smart vapor retarder with your insulation to add protection to your wall assembly. You will be building in more robustness to an area of your home that is apparently susceptible to moisture intrusion.

That’s from the outside too.  If you find some water damage around your window and you tear it out you can’t stop there.  Take your screwdriver or awl and probe the wood behind it to find out how far the damage goes. If you don’t correct the problem at the source and replace all the damaged materials, the chances of mold occurring in this area are very good..

So, don’t stop at the surface or just treat the symptoms.  You have to exhaust the symptoms and get to the source.

Remember, if you see moisture damage whether inside or outside the building don’t stop digging and probing until you get to dry.

Glass Bottle or Paper Bag?

If you wanted to keep something for 50 years would you keep it is a paper bag or a glass bottle?

This question came from a recent architect training I conducted in New York. I was engaged in a conversation about wall systems and sustainability with this group and the discussion moved to durability in relation to sustainability.

I posed that question and the response was a glass bottle. However, a case can be made for both.

Many of the passive energy saving measures we employ in our buildings can only be accomplished effectively during initial construction.  As an example; it is very difficult to add insulation to side walls over time because the cavity is designed, constructed and closed in.  If you want durability and longevity you better be building something upfront that will last at least 50 years.

To that end, do not employ difficult to replace materials that are not intended to last as long as the wall you are building. If you haven’t figured it out yet we were talking about different types of insulation.

If you can’t see it, inspect it, or fix it, you had better be sure it’s going to be around longer than you are.

Your thoughts are always welcome.