When it’s showtime and the dirt starts moving good integrated design aligns the office and the field. I’m not endorsing anything here, but the timeline suggests a whole lot of precision and alignment through integrated design. A lofty goal for a budget, and a lofty goal for any predefined building team. It’s fantastic to see it in action with good building components like 4 pane windows, energy recovery, and automated shading. A target and ambition for all sustainable endeavors. Pre-fabulous Integrated Design.
As we look to make our building much more energy efficient we also are extremely sensitive to how water can wreck havoc behind the walls when before a poorly insulated home would be fine. One overriding goal for RMPH is to incorporate lower processed materials which happen to be much more robust. Check out Joe Lsiburek’s short talk on why modern buildings can be easily knocked out by just a little bit of water, and why we stay up late at night sweating the details like vapor permeability in our wall assemblies.
Also you can read his interview with us which just won the readers choice award on Inhabitat for 2012. http://inhabitat.com/top-6-inhabitat-interviews-of-2012-vote-for-your-favorite/
The good folks at 475 High Performance Building Supply are running a series on why foam is not necessarily the first choice to look for when building high performing homes, and considering how much insulation we need in Passive House foam is looking to be one of the last choices. We are not aiming to make the most high performing building in the world at the risk of leaving a trail of toxins behind us- Passive House is equally about energy, comfort and health. MARTaK may be the first no-foam passive house in the US but we will look to make every one of our projects going forward significantly reduce and hopefully eliminate foam and achieve better results. Read on to see why…
“Green” McMansion in foam. Double trouble.
Typically the ingredients includeisocynate and polyol, with a dash of blowing agent and additives. The polyol which combines with the isocynate to form polyurethane, is generally a relatively benign alcohol compound and is used primarily as greenwash PR as it can be made with soy and other natural materials. Unfortunately this bit of soy based green(wash) is obliterated in a toxic stew.
The isocyanate is typically formed from methylene diphenyl diisocyanate or MDI. The manufacture of MDI is always done in the factory and involves such ingredients as benzene,chlorine compounds, and formaldehyde which lead to emissions of dioxins and furans; bioaccumulative toxicants, carcinogens and endocrine disruptors. The resulting MDI may be handled on the jobsite in making SPF. (Polyiso has a much higher proportion of MDI to polyol than other polyurethane foams.)
MDI is a known allergen and sensitizing toxicant. From the EPA:
“Diisocyanates are well known dermal and inhalation sensitizers in the workplace and have been documented to cause asthma, lung damage, and in severe cases, fatal reactions.”
Once you have been “sensitized” from exposure to MDI, even the tiniest subsequent exposure can have severe health effects.
The catalyst for the reaction/curing is often an amine compound or lead naphthenate. Amine is derived from ammonia. (And can produce the fishy off-gassing smell many encounter. For more on this see future post, #6 Unhealthy off-gassing.)
From the Alliance for the Polyurethanes Industry:
“Many amine-based compounds can induce histamine liberation, which, in turn, can trigger allergic and other physiological effects, including bronchoconstriction or bronchial asthma and rhinitis.
Systemic symptoms include headache, nausea, faintness, anxiety, a decrease in blood pressure, tachycardia (rapid heartbeat), itching, erythema (reddening of the skin), urticaria (hives), and facial edema (swelling). Systemic effects (those affecting the body) that are related to the pharmacological action of amines are usually transient. Typically, there are four routes of possible or potential exposure: inhalation, skin contact, eye contact, and ingestion.”
Lead naphthenate may have effects on the central nervous system and kidneys and it is advised that avoid exposure to pregnant women. The National Institute for Occupational Safety and Health (NIOSH), a division of the CDC, states: “It is strongly advised that this substance does not enter the environment.”
The hydrocarbon blowing agent HFC-245fa is now commonly used and is a potent greenhouse gas. (more on this in the next post, #2 Irredeemable global warming potential.) EPS foam boards use pentane as a blowing agent. Pentane doesn’t have high global warming potential but is a relatively poor blowing agent due to relatively high boiling point.
Primary flame retardants include HBCD and TCPP: Hexabromocyclododecane (HBCD), made of halogenated organic compounds with chlorine or bromine bonded to carbon, and Tris(1-chloro-2-propyl) phosphate (TCPP), are both persistent bioaccumulative toxins which can be found worldwide in humans, wildlife, and the environment. A recent scientific study notes:
“The chemicals are released during the product life cycle and move into the environment, humans and animals. Such halogenated ﬂame retardants act by releasing active halogen atoms (called free radicals) which can quench the chemical reactions occurring in the ﬂame. HBCD and TCPP are used additively, which means they are not chemically bonded to foam and have the potential to migrate out. They can enter the environment as releases during chemical and product manufacturing, as well as leaching from products during use and disposal.”
The same study comes to the astonishing conclusion that flame retardants, while poisoning our planet and our bodies, have been shown to be ineffective.
“Studies demonstrate that the Steiner Tunnel [ASTM E84] test does not give reliable ﬁre safety results for foam plastic insulations. Foams that meet the Steiner Tunnel test still pose a ﬁre hazard if used without a code-mandated thermal barrier. Insulations protected by a thermal barrier are ﬁre safe and the use of ﬂame retardants does not provide any additional beneﬁt.”
So in this last case we’re effectively poisoning ourselves for the illusion of fire protection. It’s not like we don’t have a choice. We can do better than foam – much better. Kick the foam habit.