I tuned into the 6 o’clock news last night (channel 4) to check on the weather forecast and see if I would be spending some quality time in my basement. While waiting for the weather forecast, I was able to catch a special report from Channel 4′s I Team or special reporting group. The topic of the report was the hidden dangers of a “green” home (not my use of quotations-I’ll get to that).
Unfortunately, this article bordered sensational. The premise of the story is that a family somewhat recently built a new home and the home was built to “green” standards (again, not my quotations). After a few months of living in the home, the pet hamsters became sick and died. After replacement hamsters also died, the homeowners became concerned and hired an indoor air consultant. After many tests the culprit was found: carbon dioxide (CO2). Let’s not confuse carbon dioxide poisoning with a more common indoor air quality concern: carbon monoxide (CO). Carbon monoxide is formed when combustion appliances (furnace, water heater, fireplace, etc.) converts propane or natural gas into heat. Carbon dioxide is formed by the simple act of breathing. If you remember back to your high school science classes, humans and animals breathe in oxygen and expel carbon dioxide.
So how did the home suffer from elevated levels of carbon dioxide? The house was not appropriately exchanging air to the outside. The common description for this condition is that the house is too tight and will not breathe.
While I do believe that the story is sensational, it does highlight a very real concern with energy efficient homes. And while this condition did create tragedy in the home, the real tragedy is that this problem is very easily avoided if the proper steps are taken during the construction of the house.
My challenges to this article are: 1) it seems the journalist has confused green with energy efficiency 2) the journalists did not take the time to discuss how this could have easily been avoided 3) what’s the deal with the quotations around green-did the homeowner go through a certified, third party verification process?
Every green building certification in which we participate (LEEDH, EarthCraft and NAHB) requires that a home’s tightness be checked with a blower door. Also, a home’s air changes (ACH) must also be calculated and if the air changes are below a certain threshold (the home is a certain tightness) fresh air must be introduced to the home or some ventilation strategy must be implemented. The Energy Star program, which is the most popular certification building program but not a comprehensive green building program, also requires fresh air if the home’s tightness is below a minimum threshold. The Energy Star program is also requiring a ventilation strategy on all homes beginning the implementation of Version 3 that will take affect January 1, 2012.
As a further testament to the importance of indoor air quality the above mentioned green building programs have mandatory point requirements in the an Indoor Air Quality section.
Indoor air quality is also very serious to E3 Innovate, which is why we insist on using a blower door. A blower door is not only a useful tool in diagnosing air leakage at a home, but it also allows a home’s air tightness to be calculated and evaluated.
The honest truth is that most existing homes are not going to achieve this minimum ACH even after a comprehensive energy efficiency upgrade, but this does not mean the home’s tightness should not be evaluated.
While I am very thankful that Channel 4 decided to bring attention to a real concern with new homes, I wish they had taken a more balanced view. Again, this problem could have easily been avoided using a whole house system-based building approach.
E3 INNOVATE, LLC