Handwashing with cool water is just as good for killing bacteria

For years we’ve been taught that, when washing hands, we have to use hot water to effectively remove bacteria.  But a new study published in the Journal of Food Protection has found no difference in washing effectiveness when hands were washed in water that was 16, 26 or 38 degrees C.  (Note: for reference, 16⁰C is a bit warmer than the water coming out of your cold water tap, but it’s colder than you’d want to swim in.)

The implication: in the words of one of the study’s authors, “We are wasting energy to heat water to a level that is not necessary.”

So – something to think about the next time you wash your hands.  Cool water is much more comfortable in summer anyway!

PS: interestingly, the biggest factor in washing effectiveness was washing technique; antimicrobial soap had little effect.


Insulate those pipes

April 16, 2013

Save money by putting foam insulation over your hot water pipes

Often our hot water taps are a long way from our hot water tanks, so we need to run the water for a while until hot water arrives.  But all that cold water ahead of the hot was once hot; it was left stranded in the pipe when the hot water tap was last turned off.  Parked in uninsulated pipes, hot water becomes cold very quickly, representing a loss of energy and a waste of money.  (Hot water heating represents about 20% of the average home’s energy bill.)

You can conserve energy and save money by installing foam pipe insulation over the pipes that carry hot water from your hot water tank to all the places it will be used.  It’s very cheap – $1 or less a meter.  And it’s very simple to install – here’s a 2 minute instructional video.

So – insulate those hot water pipes and save!

An audacious dare

May 18, 2010

Here’s a challenge for you: skip a shower sometime this week.

When I issue that dare to audiences, I often hear a snicker and a murmur that sounds a lot like, “uh-uh”.  Yet if truth be told, most of us shower every morning not because we’re dirty; we shower because it feels good.  It’s our wake-up therapy.

But our daily shower habit is one of the reasons we North Americans use more water per person than anyone on the planet.  And – even worse – much of that water is hot water, heated by fossil fuel-fired electricity.  Our morning feel-good isn’t very good for the planet.

So here’s the challenge again: skip a shower this week, and every week.  You can make a big difference for the planet!

The average person reaches for a faucet many times each day.  Without thinking, we often grab the hot water tap – even when we need such a small amount of water that hot water never actually reaches the faucet.

But, regardless of its temperature, every drop that comes out of the hot water tap costs energy (and money).  That’s because every time the hot water tap is opened, hot water starts moving from the hot water tank toward the faucet.  If it is ‘stranded’ somewhere along the way, it just cools and its energy is wasted.

So when you need just a little water, reach for the cold water tap – and save some precious hot water.