In the Tank

Hey Mr. Green,
Should I purchase a tankless, on-demand water heater?  --James in Scottsdale, Arizona

The tankless version is indisputably more efficient--around 30 percent more--than a conventional water heater, which is why a cheapskate like me wouldn't have anything else. It lasts longer too. One reason the on-demand heater is so common in Europe and Japan is that they have long been keener on saving energy than we North Americans. Even the Germans and Italians, who are more annoyingly car obsessed than Americans, are more energy wise. Another nice thing about tankless heaters is that they take up a lot less space than other models, which gives us pack rats more room to store all that valuable stuff we never use. For the truly pathological hoarder, some heaters can even be installed outside the house.

Sealing the Deal

Hey Mr. Green,
I would like to protect my outdoor wood furniture, but I don't want to use a toxic finish. I'm also wondering what to use for a deck sealer. Any ideas? --Augusta in El Sobrante, California

I wish I'd considered this question before my outdoor tables and chairs began to list and collapse when termites invaded them. For furniture made of softwood, green-building experts recommend a low-toxicity antifungal (and anti-termite) borate salt such as disodium octaborate tetrahydrate, which is sold under the brand name Timbor. Since DOT is water soluble, cover it with a low-toxicity water repellent to protect against mildew. You can whip one up by mixing an ounce of paraffin wax into three cups of exterior varnish and adding enough mineral spirits (a healthier substitute for paint thinner or turpentine) to make a gallon.  Reapply every six months to one year. For hardwoods, try products such as Sunwax, an outdoor-furniture wax with a UV sunscreen and orange oil.

Recycling Oil

Hey Mr. Green,
Americans generate 1.3 billion gallons of used motor oil every year. Oil doesn't wear out, it just gets dirty, so why don't oil-change companies re-refine this finite resource so that it can be used over and over? --Steve in Portland, Oregon

Big, deadly spills like the Exxon Valdez in Alaska get all the headlines, but every year regular folks dump around 345 million gallons of used oil into the environment, according to the Department of Energy. That's 30 times the amount that gushed out of that notorious ship. So we ought to be thankful for Jiffy Lube and its ilk, which recycle old oil, generally to be burned as industrial fuel or used in asphalt. Re-refining the oil for use as a lubricant would be a safer way to go, since burning oil releases toxic material. Unfortunately, less than 20 percent of recycled used oil is now being re-refined, according to the Department of Energy. Industry sources say there just isn't enough profit in it, nor enough government support.