Sunday, June 21, 2009

Green Development Best Practices Summary

Wednesday, Thursday and Friday, I was busy all day taking Green Development Best Practices. The instructor, Ed Lowans, consults with green developers, focusing on practicality and feasibility. He was incredibly knowledgeable and could talk miles about any subject. At times, this was great. At others, it was a little too much for me. I haven't had experience with some of the more technical systems of a building, so spending hours talking about HVAC (heating, ventilation and air conditioning) systems was completely unentertaining. However, we had some great discussions, I took a ton of notes and copied some of his presentation materials (word documents with specific system information and powerpoints) for my own future use.

Since there was SO much information on a variety of different topics concerning "green" systems within a building, I think it would be best to pull out some major points of interest and rely on my notes for more details.

Things I found particularly interesting/useful:
  • There are two major energy performance rating guides in the US and Canada. EnergyStar ratings mark the top 25% most efficient appliances. Energuild, a Canada-based rating system, labels each appliance with a kWh/year (with typical use.) Both systems have their advantages, but I had never heard of Energuide and I like being able to compare very specifically.
  • LEED is a pretty crappy way to rate a building's efficiency. LEED works on a point system. Small improvements receive the same number of points as larger, vital design issues. Also, LEED is entirely impersonal. Not all "green improvements" work with every building - sometimes, they might make the building less efficient. For example, while LEED specifies that folks should use efficient light bulbs, they don't mention spacing or maintenance of lights, so lights are often placed inefficiently. So while LEED is generally a step in the right direction, it's not perfect by any means. A similar program, ASHRAE, provides a list of specific technologies (specifically what HVAC systems) to install so that if a builder includes the items on the checklist, they should have at least a 30% reduction in energy usage.
  • The efficiency of a house depends greatly on the occupants. As soon as a house is handed over from designer to occupant, "leakage" begins - efficiency drops. That's because occupants are not always included in the planning process and don't use the buildings specifically how they are designed. I think that the solution to this would be to plan buildings together - an integrated design process. (The architect, engineer and building owners should all be involved in this process.) The occupants should know all the inner workings of the building, understanding exactly why each system was chosen. Education is the key here. Education and patience.
  • Ed spoke a bit about "smart systems." I tend to gravitate towards lower-technology buildings, but, if one is producing their own electricity, a smart system is a completely valid way to go. Heating and cooling systems can be "trained" to self-regulate.
  • It is entirely possible and sensical to heat water underneath PV panels. It's not quite as effective as a straight-up solar water heater, but it gives a nice boost to the water-heating system.
  • The average building has a 50 year lifespan. This is not because it fails, but because it becomes obsolete.
  • Pyrolysis is an awesome concept. If you burn organic matter in a 45 gallon drum, catch the released gasses, cycle them back through the system, burning them, you end up with very little/no emissions and a pile of coal, which is caught carbon that can be put back into the earth. It's a carbon-negative cycle. An interesting, quickly found article/video can be found here. One of the fellows in my class (who was also in the core class, so I've gotten to know him pretty well) is working in Belize on a pyrolysis (aka "Biochar") system. His site is here. He can't get any funding to further develop the system, even though it's a carbon-negative system.
  • We spoke about windows quite a bit. The best windows have multiple panes of glass, different glazings on the glass to treat the light, and are filled with krypton, argon or air (in order of insulation value.) They can be tilted to reduce or increase the amount of heat allowed in.
  • A well insulated house should have at least R40 walls and R60 cielings. (I already knew this. Was just throwing it out there because it is pretty important.)
  • "The first question to building a sustainable building is to ask, 'is there any way I don't have to build this building?'" - Ed. I've really adopted this mindset over the last year or so. I think a building needs a purpose, and retrofitting can be far better than building.
  • The term "Factor 9" came up quite a bit over the three days. Factor 9 refers to a 90% reduction in energy usage. Right now, it's entirely possible to build a Factor 9 building using existing, affordable technologies.
  • Radient energy and thermal energy are interestingly different. Radient is like the sun's rays on a cold day. The air isn't warm, but you can feel toasty from sitting in the sunlight. Thermal energy would refer to warm air.
  • We spoke about materials to be used in buildings based on their life-cycles. The first life cycle of a material is focused on embodied energy - how much went into extracting or producing the material. The second life cycle asks how much of the material can be recycled or reused. Wood can be reused to an extent, but not too much. Virtually 100% of steel can be reused. Concrete can only really be used for road construction stuff. The third life cycle is just a step farther. Steel continues to be reused. Concrete, gypsum, and wood can't really be used any more at that point. It only takes 20% of the energy needed to make steel to recycle it. (Steel companies should use this statistic to promote themselves.) In conclusion, steel is the most energy efficient material, but only after a very long time full of recycling. Wood is the most energy efficient for immediate use, but has limited reuse.
  • Infrastructure is everything. You cannot place a sustainable building in an unsustainable area and get the desired results. However, if the area is sustainable, the buildings on it become more sustainable by default. The key here is to revitalize the core of town. Discourage sprawl.
  • Nighttime energy is wasted. Electric companies have to produce enough energy to cover everyone, always producing more than needed so electricity is readily available. The leftover, unused energy (which is there is always more of at night) could be stored as hydrogen (which is a battery, not a creator of energy, a common misconception.)
  • Masonry stoves are amazing. I want one.

Ed also suggested many small, simple ideas that could be included in building design - creating passive vacuums that keep air circulating, light up high ceilings using a strong beam on the floor to avoid changing high-up bulbs, put a heat exchanger around the shower drain pipe to preheat incoming water, etc. Small, interesting things. I'm definitely keeping these notes for future projects.

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