My House isn’t Solar Ready, Yet

I recently had an amiable conversation with the Sales Manager from a well established Solar PV Distributor. During our conversation he asked if I had photovoltiacs mounted on the roof of my home.  Now anyone that’s ever sat in one of my classes knows that I firmly believe the cheapest alternative energy is that which you don’t need because your house is energy efficient.  In other words, to limit the cost of your alternative energy-producing components, improve the airtightness of your building. Based on the common sense of efficiency first, I replied, “My 100+ year old farmhouse isn’t energy efficient enough yet to justify investing in solar panels”. His unflinching response was “It doesn’t matter!” and that I should be taking advantage of free energy. He said his house wasn’t energy efficient either but he enjoyed lower energy bills because of his solar panels.

The notion that energy is free is ridiculous. The law of conservation of energy states that energy can neither be created nor destroyed. It can, however, be transformed via a little thing we call work. And last time I checked, work ain’t free. The energy that a solar panel produces does so at a very calculable cost. Those costs include the material cost, installation cost, maintenance costs, the depreciated value of the system over time, and ultimately the replacement cost.

Your heating and cooling costs make up 40-60 percent of the total energy used in your structure, therefore, saving on heating and cooling gives you the most bang for your buck. This is better done by by air-sealing your envelope or upgrading insulation then spending $4500 per kilowatt for PV. In addition, you’ll find it amongst the talking points of both Efficiency First and the DOE’s newest program,  Challenge Home.

Believe it or not, I’m a huge fan of Solar. I wouldn’t hesitate to install or specify a photovoltaic system in concert with an intelligently designed and built home. If you were to ask me how I’d define Solar-ready, I’d unflinchingly reply that the HERs rating should be below 50 – without any reductions from alternative energy sources.

The solar industry has brought increasingly more affordable panels and along with improved PV efficiency, the sales of roof mounted solar panels has grown exponentially. All this, combined with increased building energy efficiency is an amazing step forward into a future we should welcome. However, I will continue to always recommend improving efficiency as a more intelligent way to invest in your home’s future.

Are You Cooling Your Building with Lawn Sprinklers?

I visited a local brewpub this past hot and sunny Saturday and noticed a peculiar sight outside this popular watering hole.  Two lawn sprinklers were being used alongside the building, but there was no grass. Evidently the poor business owner is having trouble keeping his establishment cool during these hot days. Using reasonable Building Science principles, the corrective action was to increase the cooling of the refrigerant in the condensers by adding a continuous shower of water. All things considered, it’s a quick and cheap way to improve your system’s cooling capacity for the short term. Unfortunately the continuous flow of moisture is not the greatest thing for the building, the equipment, the electrical system, or the patrons navigating the sidewalk feeling as if they were being cooled while in line for the roller coaster at an amusement park.

This situation is a real failure, and far too common. First, the architect placed a major portion of the HVAC system in the front of the building. I suppose this may have happened due to convenience but it seriously detracts from the building’s facade. But wait! The solution is simple! Just build a five foot high brick wall on two sides, and create a little courtyard where all the condensers can sit out of sight. Or so it must have seemed.

Condensers work by lowering the temperature of the refrigerant by moving outside air across the coil. The air flows in through the sides and out the top. To ensure proper cooling, the manufacturers specify a minimum clearance on most, if not all, sides of the unit. In this case the units are positioned right next to each other and to add insult to injury, the courtyard created by the building and the separation walls allow for almost no horizontal air flow into the sides of the condensers (except for the small access corridor in the rear of the picture). This design failure forces heated air that has just passed through the coils to recycle as it’s drawn back down into the confined space again and again.

The reason I show this picture (beside the fact that it cracks me up) is to highlight that, in my opinion, the architect failed on multiple levels. This early 1900′s building was retrofitted into a popular restaurant/bar, but the architect failed to to accommodate  the energy demands of the structure. The lack of air-sealing and insulation upgrades have led to a structure that requires the massive amount of tonnage seen in the photo.  And despite it’s size, the system still can’t maintain comfortable temperatures due to poor planning.

The good news is the locally brewed beer is great, and the building owner got a personal invitation to our next class on Deep Energy Retrofits June 12. If he decides to join us for this four hour session  I’m confident he will walk away with proven techniques to vastly improve his building’s performance. He may even find a better use for his lawn sprinkler.

 

 

 

 

 

 

 

 

 

 

 

A Blower Door Test Doesn’t Lie

As the HERS rater set up his equipment he explained to the audience, including the homeowner and the GC, what  he was doing.  The homeowner was interested because the test had been included as a way to confirm good workmanship and the future benefit of energy savings. The GC was interested because this was his first blower door test after thirty years as a builder. As the fan started to spin and the structure’s interior went  to a negative pressure, the GC began telling me all the reasons why his company’s work was synonymous with high levels of energy efficiency. He recalled how the studs had been caulked and the plates had been sealed with gaskets. He relayed the painstaking details his crew had used to seal the windows with foam and tape. However, when the differential pressure hit the target of 50 Pascals, it was plainly obvious that the GC’s suggestion of energy efficiency was a far cry from what was delivered. The air leaking around the windows didn’t require a thermal imaging camera or smoke pencil to highlight the offending areas.  All I had to do was stand near the window and let the breeze blow through my hair.

The builder asked me how the test was going, to which I replied that his crew had failed to seal the window. His response was one of shock and denial. He insisted that they had and attempted to explain why I was wrong. My only response was to show him where to stand and how to hold the back of his hand against the corner of the window.  “The test shows us where air is leaking into or out of the envelope. It doesn’t lie.” His response? “Well, my crew does the best job they can.”

The rater packed up his gear and handed the homeowner the less than impressive report.  I’ve often wondered about the conversation that followed between the homeowner and GC.  Did the owner question the GC’s claim of being an “energy efficient builder”? And without the blower door test, would the owner have ever known otherwise?  And more importantly, did the builder change his approach with the next energy efficient home he built, or does he continue just to do “the best he can”?

In my opinion, many builders lie to themselves and mislead clients about energy efficiency. They make claims of energy performance, and still only build a code-minimum house. On the other hand, many builders are waking up to the realities of the demands made by homebuyers and the new energy codes. Many of these builders are also smart enough to back up their claims and ensure their record of performance with a blower door test.  A blower door test doesn’t lie. It is a tool that can be unimaginably helpful at confirming both past workmanship and future energy consumption. Does your next build include a blower door test?

Dancing with the SIPA Stars

Loew’s Ventana Canyon Resort in Tucson, AZ
the location for 2013′s
SIPA Annual Meeting and Conference.

Just like Jimmy Buffet Parrotheads, year after year Panelheads flock to the SIPA Annual Meeting and Conference.  This year was no exception, with manufacturers, builders, dealers and design professionals gathering in Tucson, Arizona  at the fabulous Loew’s Ventana Canyon Resort April 2-5.  We had a host of speakers, countless committee meetings, a golf tournament, networking, board meetings and dancing (more on that later) as well as the 8^th Annual Auction.  The atmosphere was energizing and optimistic with the re-emergence of the housing industry and focus on energy-efficient building.

Our presenters  came from near and far.  Fifteen speakers presented across three different tracks during Wednesday’s training: Sales/Marketing, Builder/Technical, and Timber Frame.   First time SIPA speaker/attendee Jorg Thomsen traveled from Uruguay to provide an interesting and entertaining outline of the international SIP industry and his 30+ years’ involvement.  A special thanks as well to Allison Bailes who provided his expertise in three different topics, including the importance of social media. All our speakers deserve a round of applause for helping to educate and energize the many builders who came to Tucson to learn what’s new in SIPs.

Damien Pataluna of FischerSIPs, SIPA President Al Cobb, and Irina Morozova at SIPA Annual Meeting

Our last event was the Wednesday night auction.  I admit stealing the idea from the Timber Framer’s Guild – ever met an association that couldn’t use a little extra shot of cash? It’s a great way to drop the formalities, promote unity, and network.  But more importantly, it’s a lot of fun.  So how do you end an auction in style? Dancing, of course! The SIPA crowd was treated to an exhibition of ballroom dancing from one of our own.  Manufacturer and Astair wannabe Damian Pataluna of FischerSIPs brought his lovely partner Irina Morozova to Tucson in route to Los Angeles for the 2013 Amateur Adult Championship Nine Dance Competition.  The partners amazed the crowd with five different dances, and reports on Friday confirmed that Irina and Damian had defended their title once again.

With all the effort that goes in to the many conferences, shows and association meetings I attend year after year, often the most valuable part of the experience is the networking.  For me, the SIPA Annual Meeting is  as much about the networking as the training.  This industry has some amazing people who get up every day and do amazing things, and I’m proud to be part of a group that works together for a common goal – building the SIP industry. The unity and camaraderie hasn’t always been there, but this year in Tucson it was palpable.   Hope to see you there next year, and don’t forget an item for the auction.

SIPschool Student Shares His Story

The story below comes from Carlos, a student who spent time with us last year.  He arrived at SIPschool eager to learn as much as he could about manufacturing and building with SIPs, and followed up formal classroom training with two weeks interning in the field.  Half a year later, Carlos and his brother have set up  temporary manufacturing in Texas before ultimately moving their operation to Honduras.

It all started with a phone call from my brother Billy. He is an entrepreneur who resides in Tegucigalpa, Honduras. In midst of other business ventures he develops a new interest in construction and after some research encounters the SIP panel method. His interest was sparked by the cost effectiveness, superior insulation, stability and comfort of SIP panels and knows that this would thrive in the Honduran market.  After further analysis and seeing the potential in this project Billy contacts me and fills me in on what discovered. With my 30 years of experience in manufacturing and quality control he thought I would be the ideal person to pursue this project. This immediately sparks my interest and I start research of my own online. That is where I found out about Al Cobb and his SIPschool. I immediately called them and registered for their next available training course. At the conclusion of the introduction course I immediately knew I had to continue my research extensively when I returned to Texas. The next 6 months consisted of countless hours of reading and further learning. I went on to visit different factories in Alabama, Florida and Texas to become more visually familiar with the construction method. This is where I decided to call Al Cobb and ask him about a possible internship so I could gain some hands on experience. He was on board with the idea and I immediately continued my training. This is where I learned all different aspects of the SIP method and concluded my training. When I returned to home, my brother and I decided that we were ready to buy the equipment needed and that we had to set up a temporary factory in Texas. On January 14, we started the production of the first round of SIP panels fit to all industry standards. Our next step is to move the factory permanently to Honduras and embark on the task of providing a new, safe and affordable way of construction for our people.

 

 

 

Free SIPA Membership for Design Professionals

To Vent or Not to Vent, That is the Question

I received an email today from a homeowner whose architect and GC wanted justification from a SIP expert regarding the question of roof venting on a SIP structure. The roof detail that provides “back-venting” is often called a “cold-roof”. However, in the context of SIPs, it would be far more accurate to refer to the detail as a “dry-roof”. The concept of a cold-roof is more applicable when we build up North and are concerned about ice-dams. The ventilation under the sheathing helps prevent the melting of snow and refreezing when the run-off reaches the overhang.

Whenever we strive to increase energy efficiency within a structure, it should be agreed that improving airtightness is as (if not more) important than increasing Thermal Resistance (R-Value). When we increase airtightness, we simultaneously decrease the building’s ability to dry.

Think of the 100+ year old barns that are still standing  despite routinely getting wet. Without insulation, a structure is actually far more durable because it has a greater capacity to dry. The fastest way to do harm to an old timber frame barn is to pack it with insulation and fail to ensure a good means of drying. It will get wet, it will stay wet, it will rot, and it will fail!

The diagonal furring strips define the air channel and receive the vertical board siding. Notice the polypropylene black mesh at bottom to allow air to keep pests out and let air in.

All super-insulated and airtight structures need detailing that promotes a robust capacity to dry. This detail is often used behind siding and is known as a rain screen. The gap allows air to freely move in and out which also helps to dry the cladding and help dry any unintended wetting of the wall assembly’s exterior sheathing. The added benefit to this detail is it reduces thermal drive which causes premature paint failure. An additional benefit is increased sound resistance. The air gap helps to reduce the transfer of sound vibration through the assembly.

All the benefits of back-ventilating your siding are applicable to your roof. It will improve the durability of your structure by increasing the roof’s ability to dry when it gets wet. And, remember that Murphy says it will always get wet. Back-ventilating will improve the life of your cladding and it will help improve your STC performance (sound transmission class).

It is important to note that many types of wall and roof claddings are “self-ventilating”. This is where a material choice can make a big difference. If you opt to specify a slate, tile, or multi-crimp metal roof, your roof cladding is doing double duty as a finish and as a self-venting system. If you chose a standing seam or asphalt shingle roof, your decision to add venting could be one that increases the durability of the structure.

The location of your structure must also be considered!!! I tell builders that if they want to be crappy at their trade, they should go to Phoenix and build where the climate is more forgiving with stupid mistakes. If you’re in an arid climate or one that has very little rainfall, the decision to ventilate would likely be a waste of money. However, if you were in New England, skipping a ventilating detail could spell disaster.

The decision to ventilate or not should be based on

1.   climate/location

2.  cladding type

3.  the building’s type of assembly.

Your building will always be more durable if you add ventilation!

Back ventilated metal roofing. The herringbone pattern is a good detail when your roofing runs from eave to ridge.