The Secret Life of Mr. Green

Mr. Green gets lots of questions from Sierra’s readership of 1.2 million that don't make it into the magazine or onto this blog. But he often replies to individual inquiries anyway, just for fun, and in the process sometimes even stumbles into exchanges that involve scientific discovery. For example, information about saving energy by filling empty fridge space with containers of water may emerge from the following discussion. It starts with a question from Megan in Gibsonville, North Carolina:

My Kenmore side-by-side refrigerator and freezer broke a few months ago and we had it fixed, but since then, the freezer has been empty except for ice. I shop locally and seasonally and we eat mostly fresh vegetables. I never use the freezer. Can I safely turn the freezer off, or is there something about the way the unit cools that will mess up the refrigerator half if I do this? I can't find anything in the owner's manual or online about this.

After several exchanges with one of Kenmore's technicians, who requested details such as the model number, we got the answer: “The freezer definitely needs to be turned on for the fridge to cool. If you turn it down too much, it won't keep the food. The customer has to find the appropriate settings that meet his needs."

To which I added, "So it seems like it should work keeping it on the lowest setting, but to be absolutely sure that setting the freezer too low doesn't affect the fridge, I recommend putting a thermometer in the fridge. It sounds like you guys are tech-savvy enough to do that."

Now I know she's tech-savvy is because while Megan was waiting for an answer, she e-mailed: "In the meantime, we heard the old 'fill it with milk jugs filled with water' thing. So my husband, who’s a physics professor, is trying to test this. He attached a Kill-A-Watt [an electric-use monitor] to the back of the refrigerator and has made a Google spreadsheet showing the temperature changes each hour (!), then tracking the changes after each time we add a milk jug filled with water."

Ever intent on encouraging citizen science, I asked her to share the results of this experiment. The latest word from her: "Our milk-jug experiment is going well. I'll definitely send you the results as we compile them. My husband is a perfectionist so it'll be up to me to actually convince him the data is 'good enough' to ship out."

So watch this space for the results. Or experiment with your own electric-use monitor (available for about $20 to $30) and track how much power individual appliances, computers, and other gadgets are using. You might be surprised at the waste caused by inefficient appliances, "vampire" energy drains from items left plugged in, and assorted stuff that doesn't really even need to be used.

When a Kitchen Counter Top is More Than Just That

Hey Mr. Green,

What's the most environmentally friendly counter top for the kitchen?

–Pat in Redrock, Oklahoma

This is an extraordinarily difficult question because the materials used are so different and have such different impacts on the environment. The length of time a counter will survive before it has to be replaced is also an important factor. So, while ceramic tile might require more energy to produce than, say, recycled wood, its extreme longevity gives it some environmental advantage over wood. My favorite authority on green home topics, the U.S. Green Building Council, notes that traditional ceramic tile and natural linoleum can be green options,  while plastics have some serious drawbacks. 

To help in your choice, you can consult the USGBC's list of countertops that are made with at least 20 percent recyclable materials such as glass, wood, and even paper, or from wood harvested from certified forests, natural linoleum, and bamboo at this link. You might also take a look at the GBS's "Buyer’s Guide to Green Countertop Materials" and "Choosing a Green Countertop that Works with Your Style and Your Life."

Yes, this last "life" concern is important, and because aesthetics are involved, I would hesitate to prescribe a counter on strictly environmental grounds even if somebody did come up with an infallibly green rating system. It's important to like the way things look. So one wonders: Can ugliness cause collateral damage to the environment? Do people rendered restless, irritable, and discontent by their immediate environment go out and buy Hummers to fill an aesthetic and spiritual void? Would the world be a better place if the Cathedral of Notre Dame or the Taj Mahal or other famous edifices had been built like utilitarian, efficiently constructed warehouses? Are soulless shopping malls really crypto marketing devices, the sheer banality of which drives us to drive more and more to buy more and more stuff? How has our sense of architectural beauty affected our relation to nature? What if John Muir hadn't compared mountains to marvelous temples, or Bob Dylan hadn't sung of the wild cathedral evening?

In sum, is a counter top merely a functional culinary workbench, or a path to philosophical inquiry?

Firing Up the MPG Battle Again

Hey Mr. Green,

Can you drive a stake into the persistent myth that hybrid cars are bad from a cradle-to-grave carbon footprint perspective? I am tired of someone (who is mechanically inclined and has much more time on his hands than me) going on about the MPG of his 1993 Mustang.

--Russell in Framingham, Massachusetts

I've pounded a stake into the heart of this myth on a half-dozen occasions, sometimes with acerbic wit or by way of a two-fisted feminist theory (scroll down to Feb. 21, 2008). I've corrected its contrarian faithful such as George Will and his disciples, and I've addressed the topic in my book and other venues. But it's time to swing away again, because the myth persists to slither free from its stake.

Roughly 25 percent of the hybrid car's lifetime cradle-to-grave energy use goes into manufacturing it. According to the EPA, the 2010 Prius gets 51 miles per gallon in the city and 48 on the highway, while the most efficient 1993 Mustang (a five-speed stick shift) gets 19 in the city and 27 on the highway. Let's say that the driving is evenly split between city and highway. So the Mustang averages 23 mpg, while the Prius gets 49.5.

If your friend continues to have the time to tinker with, adore, and extol his Mustang for another 150,000 miles, he'll burn 6,522 gallons of gas. The Prius will burn 3,030 gallons in the same 150,000 miles. But since about 25 percent of this amount will have been used to make the Prius, it will actually burn the equivalent of 3,788 gallons, or 2,734 fewer gallons than the Mustang. So the 'Stang will emit about 26 tons more carbon than the Prius over those miles, not to mention a lot more air pollutants like ozone, nitrogen oxide, and assorted hydrocarbons.

Of course, your buddy could lower his carbon footprint to a sub-Prius level simply by carpooling, in the event that he ever attains full-time employment.

The Dirt on Air-Dried Dishes

Hey Mr. Green,

To conserve energy, I've asked my wife to never use the dishwasher to dry the dishes but she thinks that using the "heated dry" cycle protects us against germs and she surreptitiously overrides the air-dried settings.  I argue that like millions of healthy people before us, we always "air-dried" in the dish strainer before owning a dishwasher. Can you help clarify all the benefits to this recommended climate friendly practice?

--Don in Province, New Hampshire

At the risk of echoing my fellow advice columnist Dear Abby, you've got to put a stop to this surreptitious behavior before you end up at a marriage councilor.

The heated dry cycle requires more electricity than air-drying or not drying at all. Heated drying can demand an 25 extra kilowatt hours per year or more, which will result in more than 50 pounds of carbon dioxide emissions from a coal-fired plant, along with other pollutants like sulfur dioxide and nitrogen oxides, which is why the EPA and the most respected energy conservation organizations advise us not to use the heat-dry feature. Now 50 pounds may not sound like a lot, but it is cumulative effect of small uses of power like this that contribute a lot to the 22 tons of CO2 that the average U.S. resident generates every year.

Finally, tell her to quit stressing about germs. There is no more danger in not heat-drying than if you put dishes on a rack. Just open the door of the dishwasher and let the air dry things out. We've become way too fearful of germs anyhow, thanks to an army of marketing wizards who have created an exaggerated fear of microorganisms. Moreover, some researchers suspect that a lack of exposure to germs may make kids more susceptible to allergies because insufficient experience coping with invasive substances messes up their immune systems. Even more interesting, some scientists speculate that a bacteria found in soil actually functions as an antidepressant. If the need for such a germ really explains kids' traditional propensity to make mud pies, we could stop medicating them and turn the tykes loose in the biggest, gooiest puddles we can find.