Biomimicry When Applied to Buildings

I was surfing the US DOE the other day and learned that one of the areas of research they're working on tackles the problem of all the energy used to condition all this space when the human body occupies only a small fraction of said space. This is where biomimicry comes into the picture. Biomimicry is an emerging discipline which studies nature's forms, processes and ecosystems to find clues to how our species should live. This idea is premised on the fact that homo sapiens has only been on earth 200,000 years, compared to other species some of whom have been around for hundreds of millions of years. This on a planet where life began 3.8 billions years ago.
The biomimetic approach starts with the question: what would nature do (or not do) in this situation? So take a building's interior space. Does nature condition any spaces which animals inhabit? Passively, yes. What about species similar to us? Well, other mammals have fur or hair as an insulator, which we homo sapiens do not have. So what can we do? For staying warm, mimic other mammals who have fur by layering clothing. As for cooling, we should be in smaller spaces that are naturally (passively) insulated and conditioned. Think thermal mass and natural ventilation. Now where does DOE's research come in? They're researching robotic air heating/cooling units that follow people around. But how much energy is that going to save as the heat is mixing with all the air circulating in the space? Now let's beg the question: what would nature do (or not do) in this situation? I have an idea but I'm not going to end here and leave it to you dear reader to ponder the question.

Climate Zone Map Updated for the First Time in Nearly 20 Years

Every three years, the International Code Council (ICC) updates the building codes in the International Energy Conservation Code (IECC). Changes to the IECC come from ICC staff, industry groups, government, and the general public. The IECC is the model energy code in the U.S., and updates to the 2021 edition were finalized by ICC in December 2020. One of the fundamental changes to the 2021 IECC was the designation of Climate Zones (CZ).

Climate zones are central to the IECC. Climate zones dictate many of the energy efficiency measures that a building must include, and they are especially relevant to the building envelope. Climate zones are defined at the county level and are based on weather factors like winter and summer temperatures along with humidity and rainfall (to define the "Dry" and "Marine" sub-climates). The climate zone map had not changed since the 2003 IECC.

However, with new research based on measured temperature data from over 4000 weather stations throughout North America over the last 25 years, the IECC designated changes to the CZ map for the first time in nearly 20 years. The outcome was that about 10% of counties in the U.S. were placed in a new CZ. In nearly all cases, the shift was to a warmer (lower) CZ, reflecting a general warming of the climate in those areas.

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Vinyl Windows, Whether Recycled or Not, Are Unsustainable. Period.

by Christian Stalberg & Duncan Rowe

In this article we have reviewed the sustainable use of polyvinyl plastics particularly as a material used in uPVC window frames. As mature students of the Masters Degree in Biomimicry at the Arizona State University in the US we applied, compared and contrasted the claims for use of green chemistry as a means for the practical and sustainable use of PVC. We applied Life's Principles, a set of principles and a living ethos, drawn from the 3.8 million years of best practise from Nature. Twenty six Life Principles are a discerning learning from the Biomimicry 3.8 Institute and are used as a guideline, framework and basis of principled thinking when designing new materials, products and processes or up cycling something that already exists in the human consumer world. Here, we take Life Principle's to one of the leading advocates of the green use of uPVC, that is Rehau United Polymer Solutions and their current practices for the continued use of PVC in window casings.

There have been a lot of accolades in the vinyl window manufacturing industry regarding the extent of their recycling PVC, but the truth is that they create, promote and sell a petroleum-based product that is not conducive to life. Recycling is not a solution but merely a stall tactic to avoid making the necessary investments required to replace the petrochemicals with safe components.

For example, Rehau United Polymer Solutions, recently won an award from BUILD magazine in recognition of their efforts for producing energy efficient building products with special attention being given to their TOTAL70 window product made with “…up to 100 percent post-consumer waste in the core, with only a virgin PVC-U casing”. While they’re accepting awards for recycling, they also vigorously defend their use of PVC claiming its environmental benefits, not adapting to changing conditions as more is known about the harms. This in spite of the fact that the State of California has identified PVC as a known carcinogen and the US Green Building Council discourages use of PVC products in their LEED green building certification program. Rehau states that PVC uses salt as its primary ingredient. The longer explanation is that they use chlorine in the manufacture of PVC, a corrosive gas which is a byproduct from the caustic soda manufacturing process using salt as a feedstock. This is greenwashing at its best.

A growing number of companies like Lego, Ford, Dell Computer, Coca-Cola and others have made the investments and adopted use of bioplastics in their product lines. Gary Noble, president of Bioplastics Solutions stated that “PHA can replace PVC and match performance and technical requirements, but the cost is the major issue.” Demand for bioplastics is what’s needed to lower costs. Bioplastics currently make up only 1% of the plastics market.

The TOTAL70 window product from Rehau, while it contains recycled PVC, is not truly evolving. Every time you recycle PVC, virgin additives have to be added to make the product reusable. Over time materials degrade along with performance and PVC is no exception. Recycling simply delays the inevitable, which is materials degradation to the point of unusability (end of life) followed by their disposal and subsequent release of toxic components into the environment.

In its annual reports Rehau emphasizes growth, new markets, products, etc. They admit that global megatrends like sustainability challenges them and they invest ten percent of their budget in innovation. Rehau’s manufacturing plant does not use onsite renewable energy although they do purchase green energy credits. They are pursuing resource efficiency in energy and materials use, reducing primary energy consumption and CO2 emissions by 16.8 and 26.5 percent over two years, respectively. Rehau has adapted somewhat to changing conditions, namely EU mandated PVC recycling targets. This has been demonstrated by Rehau’s acquisition of two window recycling companies DEKURA and PVC-R. The company is locally attuned to matters of energy and materials as evidenced by their participation in a number of industry recycling initiatives including VinylPlus, EPPA and Rewindo. Rehau mixes their own PVC onsite and also capture and process waste cuttings during window frame fabrication. While the TOTAL70 window only uses recyclates in its core, the Epwin Group a UK competitor has manufactured complete window profiles using 100% recycled plastic.

The TOTAL70 window product is multi-functional with modular and nested components, designed from the bottom up, has good weather resistance and builds on what works in the building products marketplace. Fitting form to function, Rehau’s offering comes in a range of colors, sizes and styles, and can readily accommodate double and triple pane glass. The TOTAL70 line smartly integrates development with growth across a range of window and door units available. Rehau’s product is responsive to changes in marketplace, like window thermal requirements in the Passivhaus® design standard.

In terms of preparing for the future where petroleum is scarce and costly however, Rehau does not appear to be balancing growth with development of alternatives to petroleum-based polymers. Furthermore, it’s expected that in order to address climate change, costs for petroleum will skyrocket as governments impose carbon taxes and mandate conversion to clean energy economies. Over the long-term, the company needs to evolve if it is to survive. Rehau needs to integrate the unexpected of climate change and rather than dig in its heels, would be well advised to switch to bio-based polymers for its window manufacturing sooner rather than later in order to remain competitive and ahead of the curve. They may also wish to consider outsourcing their PVC mixing and bypass altogether the costs of retooling for bio-based polymers.

Noble, Gary. Telephone interview. 9 Nov. 2018

How to Ensure Real Energy Savings When Rebuilding

The fires in California destroyed many homes and except for a few home sites that may be abandoned for one reason or another, most of these will be rebuilt. Out of the disaster arises an opportunity to design and build replacement homes that are not only more energy efficient than the homes that were lost but, if done properly, can be healthier and more comfortable for their inhabitants.

While building energy codes provide a modicum of energy savings, they fall far short of what can be achieved as they take what largely amounts to a 'one size fits all' prescriptive approach. In California, a building's prescribed level of building insulation and window u-values are based upon its location according to climate zone as defined by the state Title 24 Building Energy Efficiency Standards. The standards do not consider the impact on a building from site-specific landscape features such as topography, shading and wind direction. Sadly, building energy codes do not consider comfort of the building inhabitants, only energy savings.

There are energy conservation measures (ECM) that can yield substantive energy savings while providing greater comfort which are not considered in the building energy code as they are too complex to be 'dumbed down' in order to be prescriptive. One of the best examples of this is daylighting which is a very effective ECM yet is not required by the Title 24 Building Energy Efficiency Standards. Why? Because its too complicated. For if designed incorrectly, daylighting can result in overheating conditions. Another example is natural ventilation which harnesses openings in the building envelope and air pressure differentials to cause air to move through the house providing 'free cooling'. So how do you design a house that incorporates natural lighting and free cooling with real assurances of comfort? Energy modeling.

Interested in a carbon neutral or net-zero home? How you orient the building, shade the glass, incorporate daylighting and passive heating and cooling strategies plus the materials and systems you specify - the sum total of all of these will get you there. Only by using energy modeling can you incorporate all these measures to see the total impact on energy and cost savings. Combine this with life cycle cost analysis and you can even identify those ECMs where you'll get the greatest return on your investment.

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