## A Fistful of Pencils – Measuring Solar Radiation on a Building

Lucas Hamilton

Earlier this week during a webinar I conducted on working with solar radiation, I gave an example to help people visual how the energy of solar radiation strikes a building or object.

In physics and mathematics we would picture this energy as a vector component. I know that is not clear to a majority of non-science or non-mathematics practitioners so I often use an example with a fistful of pencils to help people visualize exactly what this means.  This is a fun little exercise but is not meant to be a scientific determination of the impact of solar radiation on a surface. This is simply a way to visualize the invisible.

Imagine the sunlight or energy coming across space and beating down on the surface of the roof at a normal angle which is a mathematical term for a 90-degree or right angle. To understand the impact of the solar radiation on that roof, take a piece of paper and draw a 1-inch square. Take a fistful of pencils (as many as will fit comfortably in your hand) making sure all the tips are even and bring your fist straight down on the paper striking it within the square.  Then count the number of strikes within that box and if you imagine each one of those strikes as being a unit of energy it gives you some idea of the impact of solar radiation on your roof.

If you want to imagine how that same sunlight is striking your wall, picture the angle that your wall is from that sun – usually about a 45-degree angle give or take.  Take the pencils in your hand and while sliding them to keep them flat to the paper turn your hand to a  45-degree angle and strike them into a 1-inch square box, you can see the number of strikes and what that impact would be significantly less. So if you again imagine that the pencil points are units of energy, you can see that only a fraction of the energy hits your wall compared to the roof.

This can be done with any angle and it gives you a very general idea of the solar energy impact on a surface.  While this does not give you scientific data to help you determine where your peak power would occur, it is one method that can be used to help visualize the best angle for solar panels on a roof.

There are some online tools that can help calculate the intensity of the solar radiation based on geographic location. One example of such a tool can be found at: http://www.kahl.net/solarch/.

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

## Embodied Energy Versus Operational Energy

Lucas Hamilton

Recently during a webinar I was conducting, the topic came up of embodied energy versus operational energy.  This topic continues to come up as building scientists evaluate systems with regard to their sustainability.

There are two things that can make a product green. It can be green in its manufacture or it can be green in its application.  One of the important topics for understanding the manufacture or delivery of a product is the concept of embodied energy – how much cumulative energy went into the extraction of the raw materials, the manufacture of the product and the transportation of the product to its final application.  This is the concept of embodied energy. Operational energy relates to how much energy the product uses or can save once it has been applied or installed into a system.

For instance, look at insulation. Many types of insulation are actually very energy intensive in their manufacture, however once they are installed they can save many times over within the very first year of their application. A perfect example of operational energy is fiberglass insulation. In its first year of use, fiberglass insulation can save 12 times the amount of energy it took in making and transporting the product.

So let’s not throw out the baby with the bath water. Sometimes, material that is superior in performance with regard to the life cycle of a building may have a little bit of negative upfront energy costs, however in its use can be very positive.

So don’t make a judgment solely based on the embodied energy but rather on the life cycle of the project to determine if it is positive or negative for the project itself.

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

## Human Comfort is Best Delivered by Water Not Air

Lucas Hamilton

While attending the Regenerative Network conference in California, I spent time in a LEED platinum certified building which is radiantly heated and cooled.  Recently, I have been giving presentations on human interactions with their environment. This has caused me to consider how differently the radiant heating and cooling system in the David Brower Center influences our perception of comfort.

We understand certain things about human senses such as how temperature, humidity, air speed and radiation are inter-related and together influence our perception of our surroundings.  These are the four things that will dictate how comfortable you are.  Because these things are inter-related, the way that heating and cooling is delivered has a huge influence on how you perceive your comfort level. As background and in simplified terms, these energy delivery methods are conduction, convection and radiation. A pot on the stove is conducting heat, when you pull out the spoon and blow on it to cool it is convection, and radiation is when you can stand a few feet away from the pot and feel the heat.

We traditionally heat and cool our buildings with air.  This is a most inefficient method. The idea of trying to store energy in something that has little mass makes little sense.  Using water to deliver energy as a way to comfort is very, very efficient.  This gives you radiated comfort as opposed to convection or conducted comfort.

To achieve the desired goals in energy savings delivering comfort by air may be on its way out. Using water to heat and cool buildings is a far more efficient method and it will save lots of energy going forward. But, we will have to make some personal sacrifices to accommodate this change. We may have to give up on instant gratification and develop patience through acceptance.

If you are outdoors on a cold day and enter a warm building, it will take awhile for the body to warm again to where you would say you are comfortable. However, after walking outdoors on a hot, humid day and entering an air conditioned building the cool rushing air will evaporate the sweat on your body and you cool off very quickly.  It’s like the building is blowing on the hot spoonful of soup.  When you condition a building space using surface temperatures, the energy exchange between the building and the person becomes largely dominated by radiation. While this will cool you down by allowing excess energy in the form of heat to flow out of your body and into the building through radiation, it will not be nearly as quick a process as having cold air blowing across your sweaty skin. Chances are you will continue to sweat for a few minutes after you have come inside so be ready for it.

Being patient and waiting for the comfort to occur is a small price to pay in order to make our energy go further. It sounds like a contradiction to say “exercise patience” but there you have it.

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

## JLC Live Residential Construction Show Stuns with Volume of Exhibitors and Attendees

Myron Ferguson clinic on drywall finishing

Why on a sunny, cool, dry, Rhode Island day would nearly 6,000 residential construction professionals from all over New England – and beyond – take a couple of days off, after the most brutal winter in New England history, to attend a trade show?

Why would manufacturers from all over the country flock to Providence, Rhode Island to exhibit at this trade event and why is there a higher demand for exhibit space at this show than the capacity to exhibit?

Why is this show one of the few trade events in the last three for four years to have growth as a problem?

Why? Because JLC Live, presented by The Journal of Light Construction, Remodeling, and Tools of the Trade magazines published by Hanley Wood delivers one of the highest trade show values – pound for pound, dollar for dollar – in the industry!

This show’s attendance increased by nearly 10 percent from 2010 to 2011 and the exhibitor participation increased by 15 percent.  This is extraordinary in a down economy!

Today, building technology is changing at a rapid rate. The beauty of JLC Live is the marriage of the practical side with the science/theory side attracting installers, applicators and remodelers who are eager not only to see the latest products but who want to see the science/theory and best practice applications in action by attending hands-on clinics.

Two examples of the show’s clinics supported by CertainTeed (both packed) were:

• Drywall Trade Secrets – Gypsum drywall finishing clinic conducted by Myron Ferguson, Building Specialist, demonstrating best practices of drywall installation and finishing using a new gypsum product, AirRenew™ that removes volatile organic compounds (VOC’s) from the air improving the indoor air quality.
• Home Performance SolutionsBill Robinson, Building Specialist discussed the opportunities of bringing energy efficiency to older homes.  The retrofit market will continue to grow as homeowners seek to improve the efficiencies of their building envelop. It is expected that, over the coming years, the remodeling market will grow by an annual rate of 3.5 percent.

From CertainTeed’s perspective, the benefit of an event like this is that the attendees are so excited by what they see and learn they will leave the event and go out and buy building products.  The impact is that quick.  In this economy the construction industry is a highly competitive place. Contractors and remodelers knowing they need to differentiate themselves waste no time in adding new ‘tools’ to their toolbox.

At a time when we are not ‘out of the woods’ as an industry,  it is obvious that building professionals find this show a significant value proposition making it well worth their time and resources.

If you were at JLC Live, let me know what you thought of the event.

Eric Nilsson

Eric Nilsson is Vice President, Corporate Marketing for CertainTeed Corporation

## Engage! – The Challenge for Building Science Webinars

Lucas Hamilton

CertainTeed recently launched a series of free Building Science webinars geared to architects and building professionals.  The series qualifies for Continuing Education Units with the American Institute of Architects (AIA) and the U.S. Green Building Council (USGBC) and kicks off with a series on A Systems Approach for Residential Buildings

We received very positive feedback about the content but what the audience did not like was the platform for the webinar.  Participants were required to call in on the phone for the audio which tied up their phone lines. They preferred a voiceover internet protocol.  As a result, we researched and moved to a new platform to correct this situation and it has had a positive effect for all.

Since many of you may have experience with holding and/or participating in webinars I am asking for your input on some best practices with regard to platforms and content. Such as:

• Are there types of webinars or subjects of webinars that have been more impactful or of greater value for you?
• Are there platforms that are more impactful?

CertainTeed wants to improve the connection we are making with the audience and ensure that the content is being shared as fully as possible and that requires engagement. The challenge with a webinar over an in person presentation is in the ability to engage the audience.

The engagement is a critical aspect of the webinar because it is often in the engagement that the real ‘chestnuts’ fall from that engagement – not what is on the slides – and provides the most valuable application of the content.

Does anyone have any experiences to share on engaging audience during webinars? I would love to hear from you.

I invite you to join me for the webinar series and look forward to your feedback.

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

## Rules Matter When it Comes to R-Value

Ken Forsythe

We all know there are ‘rules’ that everyone might not follow to the letter: “Speed Limit 55”…”Do Not Remove Mattress Tag Under Penalty of Law”…”Lather, rinse, repeat.”  When it comes to heating and air conditioning ductwork, there’s another rule many insulation contractors rarely follow:  “When installing bubble wrap insulation on ductwork, secure spacers every 24” to 36” around duct before applying wrap.”

While there’s no harm if you skip the “repeat” step when washing your hair, there can be serious utility bill consequences if installers leave out the placement of spacers between a duct and bubble wrap insulation. Bubble wrap insulation needs the thermal break provided by the air space that is created by spacers to achieve advertised R-values.  The actual R-value of improperly wrapped (i.e. no air space) duct with bubble wrap can be as low as R-0.90 to R-1.1.  Building Inspectors and owners need to be aware of what to look for to insure that the product performs properly.

In checking with HVAC insulation distributors to determine if insulation contractors routinely purchase air spacers with their bubble wrap, the answer is often “We’re still on our first shipment of spacers” or an outright, “We never sell any of those.”

Often bubble wrap insulation manufacturers do include spacer instructions with options for installers to create their own spacers by cutting and placing 2” wide strips of bubble wrap around the duct in intervals before applying the wrap around the duct or applying corner spacers specifically made for the purpose at each corner of rectangular duct.  But with so much pressure on insulation contractors to keep labor to a minimum, it’s hard to imagine that the vast majority are taking the time to create or use spacers on every project. Let’s face it: installers care about installing as quickly as possible for the lowest cost.

It’s true that quality bubble duct wrap may have good reflectivity and provides some protection against conductive heat gain or loss – as does fiber glass duct wrap with FSK (Foil-Scrim-Kraft) facing – however, the bubble wrap industry needs to do a better job educating installers and/or HVAC contractors. Educating the industry about the science behind adding air spacers and their integral role in delivering promised R-value is an important first step and is in everyone’s best interests.

Ken Forsythe is a Senior Product Manager for CertainTeed Mechanical/Industrial Insulation

## YouthBuild Inspires on a Cold Winter Day in Philadelphia

Current building

At this time of year, many of us are looking for something inspiring to get us in the holiday spirit.  That “something” came for me during a recent partnership announcement between Saint-Gobain, CertainTeed and YouthBuild USA.

It was a very cold day in North Philadelphia. Representatives from Saint-Gobain, CertainTeed, the City of Philadelphia and YouthBuild stood on the street in front of a corner home that had been vacant for 20 years. That vacancy is destined to end soon, because the house will be renovated by the YouthBuild Charter School of Philadelphia with support from Saint-Gobain and CertainTeed. When completed, this building will again be an affordable home that is may be LEED certified, for a first-time homebuyer.

Artist rendering of renovation

But it was not the partnership or the scope of the project that inspired me.  It was seeing and hearing the excitement in the nearly 200 teens and young adults who are part of the YouthBuild Charter School and who will work on this project. These students had dropped out of high school but, realizing that they needed to make a change in their lives, found their way to YouthBuild. Together with the YouthBuild staff, they are studying for their GED and learning skills in the building trades that will help them secure jobs when they finish the program. That was inspiring!

Two of the students shared their stories; teen pregnancy, substance abuse, criminal activity – you get the idea. You could feel that their stories were representative of most of the students braving the cold, winter air.  The spirit on the street was overwhelming and particularly so when Dorothy Stoneman, president and founder of the YouthBuild USA program spoke about their commitment. That was inspiring!

YouthBuild was started by Stoneman in East Harlem, New York in 1978 to address core issues facing low-income communities – housing, education, employment, crime prevention, leadership development and she has seen the program grow to 273 programs in 45 states, Washington, D.C. and the Virgin Islands. 92,000 YouthBuild students have built 19,000 units of affordable, increasingly green, housing since 1994.  That was inspiring!

As this partnership develops and our experts, like our main blogger Lucas Hamilton, help train YouthBuild students in green techniques, product knowledge and best practices in building we will share more inspiration.  Have you been inspired recently?

## Even Professionals Can Miss the Obvious

Lucas Hamilton

It is true that even someone who is entrenched in Building Science and sustainability can be caught off guard when evaluating home situations.

We recently had to replace our hot water heater at home. Here was a combustion appliance right in front of my face a few times a week and I didn’t realize how badly it had been operating.  I suspected that when the dryer was running it was back drafting the hot water heater adjacent to it.  This is fairly common in basements because dryers are so powerful they can depressurize the space and pull the air back down the chimney.  I wasn’t really concerned because it was in the basement which is not very air tight since it dates back to the 1880’s.

However, when installing the new hot water heater I discovered that it wasn’t drafting properly even when the adjacent clothes dryer was not running.  The problem was much bigger than I thought. We had to move to a power vented water heater which includes a fan on top of the appliance so when the hot water heater fires up, rather than letting the buoyancy of the warm combustion gases rise up the chimney, they get sent through a fan and powered out the wall away from the house. I had become blind to the situation because it was something I saw almost every day.

Whenever I would go down the basement, I could smell the gases but I just got used to it.  We weren’t experiencing any ill effects from it, thankfully.  But it was a potential tragedy waiting to happen either from the fumes or possible explosion and fire.

The moral of the story is even if you have been in construction your whole life, it’s good to get a fresh perspective from time to time. Pay a professional to inspect your heating and cooling systems (including hot water heaters)once a year.

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

## Is Polyethylene Creating Potential for Mold?

Lucas Hamilton

Last week, I was in Calgary, Alberta, Canada for one of CertainTeed’s Be Certain events conducting training sessions on designing for Mold and Moisture control in buildings.  In preparation for the sessions, I ran computer simulations on typical construction models in Calgary.  This gave me a better awareness of how they build as well as scientific understanding of construction practices in the province.

In extremely cold and dry climates like Calgary, which is similar to Colorado, use of exterior insulations is very common.  This practice emphasizes the use of insulation on the outside of the building.  This cuts down the thermal connectivity of the building frame to make the building more energy efficient.

The 2009 International Energy Conservation Code (IECC) mandates the use of exterior insulation in cold climates. However, when you do this with traditional materials such as rigid foam plastics, you may reduce the potential to dry a building to the outside.  If a wall gets wet normally, dry air on the outside can act as a reservoir to dry the building. When insulations like extruded polystyrenes are used on the outside of the building, while being extremely energy efficient, they may reduce this drying potential.

Some new computer modeling tools have the ability to create window leaks and other scenarios that could occur from construction defects that would place water into the wall.  In the Calgary scenarios I ran, if a window leaks and the water is not drained to the exterior surface of the water resistive barrier, it becomes trapped between two non-breathing layers – the exterior insulation and the interior traditional vapor retarder polyethylene (which they still use in Alberta.)  The wall can not dry and this creates the risk of growing mold.

Building scientists and manufacturers have been preaching eliminating polyethylene from our buildings here in the U.S. for quite awhile, and promoting the use of smart vapor retarders as a solution to the problem.

As construction practices change to keep more energy in the building, some of the measures taken may unfortunately alter the traditional moisture balance of the assemblies and actually reduce our tolerance of intruding moisture. We must be very mindful of this as we continue to tighten our buildings while striving for improved indoor environmental quality.

We conclude our Be Certain events in Toronto and Vancouver later this month.  Stay tuned for how mold and moisture affect the building envelope in Ontario and British Columbia.

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

## Indoor Air Quality Has A New Champion

Improving the indoor air quality of buildings is a large part of the sustainability movement and as we continue to address energy efficiency through air tightness in assemblies, the issue of indoor air quality will continue to be a focal point.

People spend about 90 percent of their time indoors so the quality of the air around them, where they live, work and play is very important.  Educational and health care environments draw even greater scrutiny due to the sensitivities of the young and those with potential respiratory issues.Volatile organic compounds (VOCs), formaldehyde and other aldehydes, are seen as common compromises to air quality.  VOCs are all around us, come from many sources, and often move freely in and out of building components. People, themselves, carry VOCs into buildings through the wearing of permanent-press clothing and exposure to secondhand smoke.

Fortunately, there is a first-of-its-kind wallboard, called AirRenew™.  AirRenew is designed to clean the air and remove a particular family of VOCs by drawing them into the board, trapping them, and utilizing a patented technology to break down these VOCs into inert compounds. Those inert compounds will stay in the gypsum board for the service life of the board.  These inert compounds created inside the core are not harmful and the original VOCs will never be released back into the air.

This revolutionary gypsum board, which will be available soon, will have a positive impact on public buildings, especially when qualifying for Leadership in Energy and Environmental Design (LEED ™) or other green rating program certifications.  Indoor Air Quality (IAQ) strategies incorporating AirRenew meet the intent of the sustainability Triple Bottom Line of economic prosperity, social responsibility and environmental stewardship.

AirRenew has undergone a battery of independent testing. Preliminary tests show that AirRenew maintains its performance when painted with a permeable paint. Finishing that results in an impermeable surface, such as vinyl wallcoverings, would reduce the porosity of the board surface and are not recommended. Permeable paints currently serve over 70 percent of the interior wall coatings market. Since most sustainable and LEED models are moving away from solvent based coatings, this is not perceived as a limitation.

LEED for Schools Indoor Environmental Quality (IEQ) Credit 3.2 sets a maximum concentration of 27 parts per billion for formaldehyde, however many studies have shown that this is often exceeded. The mold resistance performance of AirRenew also contributes to LEED for Schools IEQ Credit 10 for mold prevention. The GREENGUARD® Environmental Institute has many resources documenting the issues of indoor air quality and the need for reducing VOCs especially in schools.

It has been exciting to work on a product that provides a real solution to an issue that has long needed a champion product.