What if We Could Make Buildings Sweat?

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

Following up on the previous post “Can We Design Buildings for Heat and Cooling that Mimic the Human Body”, a similar question popped into my head regarding making buildings sweat.

The evaporation of water is an endothermic process that cools a surface. Evaporation of sweat from the skin surface has a cooling effect due to this phenomenon. Hence, in hot weather, or when the individual’s muscles heat up due to exertion, more sweat is produced in response to your rising internal thermostat. Why couldn’t this same process be applied to buildings?

What if there was a way to take the condensation that often occurs at sunrise, capture it and re-release it as needed.  Could we create materials, while not letting moisture intrude into the building, that could capture the moisture that naturally occurs and evaporate it off in the daytime when the sun hit the walls to cool it off?  

Obviously this would be a benefit in climates where we are using a great deal of cooling. We don’t want this occurring in cold climates for a variety of reasons. That’s a discussion for another day.

Are there any ideas out there?  When people get hot, they sweat and it cools them off.  Is it possible to apply this concept to buildings?

Simple Changes Could Help Consumers Save on HVAC

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

California has again pushed their energy bar higher.  One of the things that I love about California’s energy program is that they are now requiring an independent evaluation and commissioning beyond the air conditioning contractor of the sizing and installation of air conditioning systems. 

Recently, I participated in a workshop with a Philadelphia-based builder. He is a very professional, conscientious builder who stays in touch with building science and education. He brought his mechanical contractor to the workshop and we had a chance to talk about the way homes are built and particularly the mechanical systems. 

Here is the situation:

  • There are still ‘rules of thumb’ being applied to the sizing of mechanical systems in our homes. 
  • Manufacturers make changes to equipment to help those ‘rules of thumb’ meet the requirements, especially regarding motors and equipment that can tune itself to the needs of the house. 

What we really need are systems that are designed and installed to the actual house. 

We can’t expect equipment to be continuously updated or modified to make up for our lack of willingness to do a simple calculation as to what the house really needs. It’s not just about the tonnage of air conditioning and the size of the heating units.  It is mostly about the delivery – the physics of the delivery – of that comfort.

When someone tells me something regarding heating or cooling that just isn’t sitting well and I need a gut check, my gut actually lives out in Missouri and his name is Eric Kjelshus. He is a Missouri Mechanical Contractor with his own company, Eric Kjelshus Energy. He is a smart, thorough, well studied mechanical contractor who cares about this stuff far beyond anyone else I have come across.

It seems like many of the builders I have spoken with have been spending a lot of effort (effort = $$) after the sale trying to make the homes they have constructed meet the comfort expectations of the owners. This leads me to wonder if there are things we consistently get wrong with regard to how we deliver comfort. Time for another gut check!

Here is what Eric taught me:

We under return air in our homes.  Very few people consistently measure static pressures in the HVAC system to find out if it is balanced. If they did they would see that the system is not returning the same volume of air it is supplying. When we under return, we force the system to pull make-up air from outside the home.  Air conditioning is more efficient when the air is dry. For most of us residing east of the Rocky Mountains, the return air in our homes is both cooler and dryer than the air outside during our cooling periods. Pulling unconditioned and uncontrolled air from outside the home into the system is a big efficiency penalty and it’s one we pay for over and over again. Why not simply return the correct volume of conditioned air back to the unit? Not only is this an elegant, passive solution to the problem –  it comes with a much lower up front cost than high tech solutions.

So hats off to California for requiring that trained professionals check these systems to ensure they are properly sized and installed. We as consumers can get much better value out of systems that are less sophisticated but are sized and built right.

Off-Site Manufacturing Could Play a Larger Part in the Building Renaissance

Danny Small

Danny Small

Danny Small is Manager, Building Science Development for CertainTeed Corporation

Lately I’ve been revisiting the benefits of modular or prefabricated home construction, otherwise known as off-site manufacturing (“OSM”). There are several advantages to this method of construction that could be attractive to consumers looking to build a custom home.

This isn’t your daddy’s mobile home we’re talking about here.  The traditional manufactured (“mobile “) home is built to special Housing and Urban Development (HUD) building codes.  These homes are extremely simple, lower-end homes constructed in one or two pieces on a steel frame.

Today’s modular home can be beautiful, complex, exquisitely detailed and of the highest quality.  It’s built in modules or panels, in a clean, climate-controlled facility to meet (and often exceed) standard building codes for the area where the home will be finished.   The modules or panels are then shipped to the construction site, where they are permanently assembled on a full foundation, and the final details are finished.  Once completed, these homes are indistinguishable from site-built homes.  For some examples, check out Haven Custom Homes’ gallery.

While off-site construction has been around for decades, most of the earlier homes fell into that category of mobile (HUD-code) homes.  However, the move toward more sustainable, energy-efficient, healthy homes creates compelling reasons to look at modular as a truly viable method for all construction.

Some of the advantages of offsite construction are:

  • Construction can begin while foundation work is done, reducing the overall build time by several weeks.
  • Because building is done indoors in a climate-controlled facility, there are no weather delays.  Crews can work year round with no problem.
  • The home is built dry and clean because the wood is not subjected to dampness or dirt.  This could make for a healthier house.
  • Greater accuracy in cutting is possible because precision equipment can be utilized.
  • Lower costs because of consistency with crews and minimal lost time.  An off-site built home can cost up to 15-20 percent less than the same home built on-site. (Source: NAHB)  Savings for commercial construction can be much higher.
  • Very low waste.  Just about all remnants can be re-used for other projects.  This enables contractors to purchase more wisely.
  • Off-site manufacturers can ship up to 500 miles from their factory.
  • The building envelope is fully customizable, enabling increased energy efficiency in the wall and ceiling systems, as well as design features that meet the needs of the occupants.
  • Modular building, especially in commercial, enables easy expansion to buildings when needed.

Although off-site construction currently accounts for only two percent of construction in the U.S., the industry is gaining popularity.  In Europe, especially countries like Sweden, this type of construction is on the rise and accounts for up to 40 percent of new construction. 

If you are considering building a new home, a vacation home or a small office, do a cost comparison for on-site versus off-site construction.  You may be surprised by what you find.

It is Spring Tune-Up Time for Your Home

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

It is spring and we just celebrated the 42nd Anniversary of Earth Day. While you are contemplating changes you can make to your home and property to conserve energy or improve curb appeal in a re-heating real estate market, keep in mind that this is the perfect time to do a home inspection and make sure that your home is efficient, safe and in-keeping with the Earth Day ideals.

Here are a few places you should inspect:

  • Inspect your roof for missing or broken shingles or possible places where water could come in. If your roof is not ventilated properly you could have damage from ice dams. Nothing could be greener than making our existing resources last longer and your roof is the first line of defense.
  • Check your attic or crawl space to make sure that water is not coming in.  It is also a good time to see if you need to add additional insulation to your attic space. The attic is one of the easiest places in a home to add insulation and insulation prices are about as low as they get right now so no point in waiting.
  • Clean your gutters.  Make sure they are cleared for the rainy season. Leaves and dirt can build up in any season. Clogged gutters are one of the most efficient ways to redirect water back into your building once you have already shed it.
  • Tune up your air conditioner.  It is the prime time for specials from contractors. Making sure that your unit is working properly can help save on utility bills and actually improve your indoor air quality.
  • Check your walls and foundation for any cracks that could cause moisture infiltration. You must maintain your barriers.
  • Check the basement for mold. When the temperature gets above 41 degrees that is when mold is happy. If mold is present you will be able to smell it. If it smells bad it is bad.

If you have an older home it is critical to make upgrades and improvements when signs of weakness appear.  Taking care of simple repairs will save you money over time but will also make your home more competitive in the marketplace and make for a healthier habitat for you and your family.

Sustainability Gaining Momentum for Government Managed Buildings

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

I recently had the pleasure of doing a presentation to the General Services Administration (GSA) region 3 office in Philadelphia.  I was invited by a GSA architect who had participated in a previous seminar I had conducted for the American Institute of Architects (AIA).  The presentation was also simulcast to other GSA offices as well as employees who were telecommuting.

What I was not aware of prior to my visit is that GSA in responsible for public buildings that are non-military, non-postal service or other organizations that control their own real estate around the county. Not only do they have continuing education requirements within their organization they have a strong emphasis on sustainability. That’s exactly what you want to hear from government.

GSA serves as the property managers for many of the buildings around us every day. Given that at least 90 percent of our building inventory needs to be upgraded for energy efficiency, it was reassuring to see that the folks who are responsible for government controlled public buildings are on board with sustainability and are staying on the leading edge of knowledge. I was especially pleased to learn that the emphasis of sustainability doesn’t simply stop at how a building is designed and constructed but goes all the way through the way the GSA operates and procures for these buildings.

It was great to see that the culture of GSA is entrenched in sustainability.  That, for me, sends a message that we are on the right track of a very long road toward significant improvements in reducing the carbon footprint of our building inventory.

The NAHB International Builders’ Show – A Constant in a Changing Landscape

Mike Loughery

Mike Loughery is Director, Corporate Marketing Communications for CertainTeed Corporation

Here we are once again, heading to the International Builders’ Show in Orlando, Florida.  In the days of the housing boom, you could get a feel for the attendance and enthusiasm by how packed the plane was and the fact that it was filled with builders and contractors.

The past few years have been tough though.  Attendance, which once peaked in the low one-hundred thousands, was a mere shadow of itself a year ago with about 47,000 walking through the turnstiles. 

What will this year hold?  Well, I’m sitting on the plane.  It’s packed and a good number of the folks seem to be in the building trades (albeit for the few families headed you know where!).  Enthusiasm?  Well, not sure yet on that one.  But I know that tomorrow I will enter the hall, see all the displays, and hear the buzz of business taking place.  There is nothing as gratifying as spending four days talking with the trades about the latest products and innovations in the marketplace. 

The temptation for some might be to shrink away and not exhibit.  However, we all have businesses to run and CertainTeed representatives find talking to an engaged audience, whether it’s 50,000 or 100,000 an excellent opportunity to showcase some of the industry’s most innovative new products.  Products that improve indoor environmental quality, energy efficiency, comfort and aesthetics will be showcased as well as our team of building scientists will be available at booth W4051 to answer your most challenging questions.

Feel like swinging a hammer or learning from our experts?  We have product installation demos going on outside in P3, showcasing blowing and spray foam insulation, decking, siding and solar roofing

Can’t make it to the show this year?  Well, you can still be part of the action through a special webpage dedicated to the IBS show which will have a live Twitter feed that you can follow.  You may want to bookmark www.certainteed.com/ibs  so you can refer to it over the next few days.

If you’re in Orlando this week, stop by and say hi.  Let us know how things are going for you in your market.

YouthBuild Akron, Ohio Goes for LEED with CertainTeed

 

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

CertainTeed and our parent company Saint-Gobain have a three-year partnership with YouthBuild USA providing expertise and products for projects they are undertaking in various cities around the U.S.  Last week, I conducted some training programs for the YouthBuild organization in Akron, Ohio on the building envelope and how to select products to help them meet their LEED goals. YouthBuild helps train young adults in green building techniques and construction practices on hands-on projects in their community.

This project is a renovation of an existing home and based on the information from their design charrette, they may reach LEED Platinum which would be awesome not only for a low income housing project but as far as I can tell it is the first LEED H Platinum project in Akron.  The best part is that the house next to this home was previously rehabbed by YouthBuild and is nearly identical in layout so they should be able to do some comparisons of the energy savings.  Of course, results won’t be as “cut and dry” as we might like because you can’t control the behaviors of the occupants.  However, we should be able to get some relative comparisons as the homes are of identical size with identical orientations.

Based on the products and systems Akron YouthBuild are planning to use, they are hoping to renovate to a Home Energy Rating System (HERS) score of 65. This means that the home consumes 35 percent less energy than what is building code standard of 100.  This is a very aggressive score. HERS is a program of the Residential Energy Services Network and a registered HERS rater is working with them on this project.

While not all the products/systems have been selected, during our visit we made some suggestions especially for insulation, gypsum and roofing based on their goals and the building assembly to help with the EPP (Environmentally Preferable Products).  We were also able to add points because of the proximity of CertainTeed plants to the project location.

It is great to see these projects educating builders of the future in green and sustainable techniques. I also believe it sends the right message to the community in that a sustainable habitat is possible for everyone.

Don’t Forget the Fireplace When Winterizing Your Home

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

One home feature that is popular because of its charm is the fireplace.  While many homeowners like to have one to provide a cozy room on cold, damp winter days you also have to remember that a fireplace represents a big hole leading up to the sky in your building envelope. If the chimney is not properly sealed when you are winterizing your home your indoor heat will simply go straight up the chimney.

In many homes, the chimney actually accounts for more air leakage than windows and doors.

Many homeowners, like me, don’t use their fireplace during the heating season because it is easy to create a back draft from the fireplace in an air tight home.  If I am using my fireplace and my furnace kicks on it will cause the smoke to back up into the house unless a window in the room is kept open a crack.

When you are not using your fireplace you should make sure that you have a system in place to seal the chimney and make it air tight.  Standard chimney dampers are simply not air-tight enough. There are two methods that could help tighten your chimney:

  • Install a chimney cap that will snug down on the top of the chimney that can be closed and opened by reaching into the chimney and pulling the chain to secure the cap – or release the cap – on the top of the chimney.
  • Install a bladder-like devise that – using the reverse air feature on your shop vacuum – will fill the bladder and create an air barrier.

There are dozens of common sense ways to deal with air leakage from your fireplace.

However, if you do choose an air tightening devise remember to remove it before you use your fireplace or you will have a major smoke event in your home!

Remember, you don’t have to sacrifice charm or aesthetics when working toward high efficiency in the home but you do need to minimize air loss everywhere you can.

Sustainability on Display at Louisiana State University

 
 

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

I recently visited Louisiana State University to speak to the Baton Rouge Chapter of Construction Specification Institute (CSI). The sessions were held to assist the Chapter members earning Continuing Education Units for their professional credential renewals.

Steve Tubré who is the program chair for the chapter and Construction Contract Administrator and Director of Quality Assurance for Billes Partners, LLC in Baton Rouge invited me but I had no idea what a wonderful resource I would be introduced to while there.

LaHouse at LSU

LaHouse at LSU

The meeting was held in the LaHouse – Home and Landscape Resource Center which is part of the LSU Agricultural Center.  The house is a research-based showcase of solutions and an educational outreach program designed to help shape the future with homes that offer more comfort, durability, value, convenience, environmental quality, safety and better health with less energy, water, pollution, waste, damage and loss.

Throughout the house, the building envelope has cut-away sections to show the various different layers of construction which were employed in each different systems. Some examples of what you can see are the constituent layers of a stucco wall, and EIFS wall, and an insulated concrete form (ICF) wall.

What a wonderful way to illustrate the concepts of sustainable design and educate visitors about designs and systems to create the homes of the future. The LaHouse Resource Center provides a local and living showcase of solutions for sustainable homes and landscaping. The fact that it is part of the Ag Center and not the school of design was also intriguing.

The LSU Agricultural Center is in view of the football stadium so the next time you find yourself at a Tigers game swing by the LaHouse for some inspiration.

When it Comes to Air Tightness in Buildings – Don’t Forget the Garage

 
 

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

Many of our houses have attached garages which are, for the most part, unconditioned space within our habitat.  It is the interface of these two spaces which so often fails in our attempts to conserve energy and have superior indoor air quality. 

For starters, you have to make sure that the garage is air sealed from the rest of the structure because of what you store in that space. You store things in your garage because you want them out of the weather but you don’t want them “indoors.” Very often negative pressure is generated in the home by exhaust fans and dryers. In your home’s attempt to reach a neutral pressure with the exterior, it will often pull air from the garage into the home.  Now all of the gaseous and particulate contamination which is associated with what you are storing and doing in your garage is coming into your home. Think about what is on the other side of these “interior” walls – typically they are the rooms where we spend the most of our waking hours; kitchen and family room. If the separation plane between these spaces is not made air-tight we might as well move into the garage.

One small detail which is best addressed during the time of construction is breaking the continuity of framing chases between the garage and the house typically found in the garage ceiling. As the second floor framing runs continuously across one of the garage interior walls, air-tight blocking needs to be installed between floor framing to close this avenue of air migration. This is obviously easier to achieve with dimensional floor framing or “TJI” (Trus Joist I) than it is with modern trusses. Also ensure that any doors leading from the garage to the living space are properly sealed and air tight. Get a new door sweep if the old one is worn out. One great indicator of an air leaky passage door is a dirt “shadow” in the carpet just inside the sweep. Carpet fibers make excellent air filters and atypical soiling patterns are great indicators of air flows.

Once you’ve decreased uncontrolled air flow between the home and the garage is there added value by adding an insulated exterior garage door?  Absolutely! Any way that you can tighten or insulate the envelop will improve the efficiency. When you are making any changes with regard to air tightness in the home don’t forget to include the garage in your decisions.