Musings on Mazria, Lstiburek and Gifford: Part Three
I just want to set the record straight on one point: I have not imbibed the USGBC Koolaid. I do like its mission, goals, and products, and the organization has the best start of any rating system out there. As I have stated many times before, I’m a biologist by training and I am way into evolutionary biology. That’s all that needs to happen here. There are aspects of LEED that need improvement, so the USGBC simply needs to evolve in order to adapt to the changing environment: building science knowledge and feedback loops. It’s a lot like natural selection in a way. Survival of the fittest and change over time are important to businesses and businesspeople that are interested in the survival of their species.
Like I have stated before, I’m no PhD, engineer, or architect. I’d like to think that I will always be a humble student of the natural world. In that role, I’m trying to let the dissonance that exists in our industry soak in. Here’s my take on one of the bones of contention. When building, I subscribe to the mantra, “Build tight and ventilate right”. AIR SEALING!!!!! The tighter, the better, in my opinion. One hundred years ago, heating was cheap. Wood, coal, whatever—it was cheap. Not so cheap anymore. The tighter the home, the less conditioned air you lose. That’s a good thing. Not allowing for fresh-air ventilation or letting in so much unconditioned air that energy efficiency and humidity levels are compromised is a bad a bad thing. It’s a must to let in fresh air when building a supertight shell.
Let me tie this into my current thread on the banter between Lstiburek/Gifford and the USGBC. In Lstiburek’s paper, “Prioritizing Green: It’s The Energy, Stupid”, Dr. Lstiburek takes great offense to the aforementioned NBI study on energy efficiency in LEED NC buildings. I’d like to comment on one specific point that he makes in the paper:
… don’t overventilate. This idea of getting green points by increasing the rates above those specified by ASHRAE Standard 62 is just madness. Whatever happened to source control? If you don’t build stupid materials into the building, don’t do stupid things in the building, and don’t connect the interior to exterior via the parking garage, 62 works very well.
Lstiburek, an ASHRAE Fellow, is referring to LEED NC Environmental Quality Credit 2, “Increased Ventilation,” which is obtained by increasing ventilation rates by 30% over those prescribed by ASHRAE 62. Another ASHRAE Fellow, Steven Taylor, stated this in a report:
It is acknowledged that increasing ventilation rates will, in most applications and climates, increase energy use. However, the impact is relatively small, and it can be mitigated using heat recovery and other technologies. . . .The benefits of these credits are deemed to outweigh the energy impacts. Similarly, it is argued that the energy impact of increased ventilation is more than offset by the health and productivity benefits. EQ Credit 2 has been completely revised to require an increase in ventilation rates of 30% above Standard 62.1-2004 rates. The increase (and even higher rates) can be justified by recent research showing higher outdoor air rates improve occupant productivity and reduce sick building syndrome symptoms.
So how much is too much? I don’t have the answer to that. In the residential realm, in 99% of the houses that I have built, I have installed either a Venmar Constructo or a Venmar HEPA 4000, which probably provides more air changes than necessary for a home that size. Almost all of those houses are under 3,000 square feet. I know by following them over the years that the energy bills are quite low and the indoor air quality (IAQ) is quite good. A family from New Jersey moved into one of our homes with their 9-year-old son, who suffered from chronic, severe asthma. Within two months, all of his symptoms were gone. Another instance involved a family from New Mexico. The wife was chemically sensitive and wanted to seriously vet the home before they moved in. She had a variety of tests run on the IAQ of the home (including mold, VOCs and radon), and it passed all of them with flying colors. This is a tiny data set, but I know (especially since I live in one of them) that our houses work: low energy bills and good IAQ.
Unfortunately, I agree with a lot of what Gifford and Lstiburek say in their papers. What I classify as unfortunate is that you have to sift through so many condescending statements, epithets, and sardonic wit that the points get buried. In a world where (in my opinion) so many of us can’t wait for good news, can you guys try to stay constructive and positive?
I agree that we need to base the “greenness” of buildings on performance or extremely accurate models (which don’t seem to exist for all cases). I agree that overventilation can be detrimental. I agree that overglazing can negatively affect energy efficiency and comfort. I recently visited an organization’s national headquarters in Washington, D.C., a very big organization at that. It was LEED Silver—certified, but, as the tour guide admitted, the building has huge utility bills and is not performing as modeled. That part of the system needs to be fixed.
All of these things need attention, so let’s bring it to the attention of the necessary individuals. I do suggest that when you present information or make constructive suggestions that you don’t refer to the recipient as stupid. You may get a bit further that way. Definitely, a rose IS a rose, but talking nicely even to plants can help them grow.
Next post, I’ll spout a bit about what I think the key is to the success of the green market shift in light of the new administration and the American Recovery and Reinvestment Act.