Last week I wrote up an article about cutting your home heating costs. The discussion that followed in the comments section was full of more great information, and it even led to me making a small change in my own house that should work out to surprisingly large savings. This rather simple trick was: Changing my master bathroom showerhead from a 2.5 gallon-per-minute model to a 1.5 GPM one.
Now, you’d think that as a house builder who writes a frugality and personal finance blog on the side, I would already know the full story about water-saving showerheads. I thought I did too, but I was wrong! And because I didn’t know this secret, I’m going to assume that there’s a good percentage of you out there who don’t know it either. So here is the scoop:
In recent decades, the US Environmental Protection Agency has been tightening up the rules on how efficient household appliances and fixtures must be in order to be sold in stores. Various regulation-haters have complained at every step, but regulations of this type actually bring people more freedom – freedom from their own stupidity! Nobody knows or cares how much energy they are using, they just live their lives and pay the utility bills. If you force the manufacturers to offer better products, the people buy them and unwittingly save themselves a shitload of money, all while helping the planet. It’s a win/win situation.
Here are some examples: In the olden days, toilets required as much as 3.5 or even 5 gallons of water for each flush. Simple re-engineering of toilets has brought this down to 1.6 GPF and more recently 1.28. These new toilets still work just fine, and don’t cost noticeably more, but each one ends up saving the equivalent of a full backyard swimming pool of precious drinking water every two years.
And more significantly, showerheads have also been re-engineered to use less water and heat energy. Before 1992, showerheads could dump out 4-8 gallons per minute. In the 1990s, the US standard became 2.5 GPM. This is when I started building things, and I have always felt good and virtuous about installing and using 2.5GPM showerheads.
But someone recently informed me that there are 1.5GPM and even 1.25GPM models that are carefully designed to be just as nice as a standard 2.5’er.
For example, here’s a 1.5 gallon showerhead on Amazon that has over 150 reviews averaging almost 5 stars = for under ten bucks.
“Could this really be?”, I wondered. “I work hard sometimes, and I get coated with sweat, concrete, sawdust, and blood. And I’m a wealthy man who can afford a nice shower. As creature comforts go, it’s a pretty cheap one, so I will not compromise on a good hot shower with plenty of pressure and cleaning action”.
But at the same time, I did some calculations to see what kind of savings were at stake:
Mr. Money Mustache: 3 showers per week on average, duration of 5 minutes, temperature 107 degrees F.
Mrs. Money Mustache: 4 showers per week, duration 10 minutes, temperature 107 degrees F.
Junior ‘Stash: still taking about 2 baths/week, hopefully will graduate to showers one of these years.
Total shower duration per year: 55 minutes per week x 52 weeks = 2860 minutes per year.
How much does a shower cost per minute?
The 2.5 gallons of water I use per minute cost about 1.25 cents according to my utility bill (0.5 cents per gallon).
These 2.5 gallons of water weigh 20.5 pounds. This water enters an average house at about 50 degrees Fahrenheit and must be heated by an additional 57 degrees.
Since we learned earlier that it takes one BTU to heat 1 pound of water by 1 degree, it means the shower is consuming 57 x 20.5 = 1171 BTU of heat per minute. After accounting for the losses in a standard natural gas water heater, you get about 58,000 BTU of water heating for each dollar you spend on natural gas… so…
A hot shower with a standard showerhead costs about 3.25 cents per minute.
With an electric water heater and 12c/kwh electricity, this cost would be about 5.3 cents per minute.
So if you’ve ever wondered about the cost for a 10 minute shower, now you know: it is between 32 and 53 cents.
Now how much can the Money Mustache family save each year by going from a 2.5GPM showerhead to a 1.5GPM one?
At 2860 minutes per year, we were spending $92.95 per year on showers (!)
By dropping from 2.5GPM to 1.5GPM. we save 40%, which is $37.18 per year.
Wowee. Almost $40 per year from a $10 device is a much bigger return on investment than I’ll get anywhere else. And it’s over 5% of my annual spending on natural gas. So it’s a worthwhile savings. But is it going to hurt my tradition of enjoying Hearty Manly Showers where the water runs black from the extreme filth I am scrubbing off?
To find out, I looked up some of the well-reviewed 1.5GPM showerheads on Amazon.com like this one*. The people seemed to say that their showers were just fine, and many couldn’t even notice the difference when dropping from 2.5GPM. Good enough for me. I picked one up for $10 bucks, and screwed it on.
It is great! I too can hardly notice the difference, my showers still feel great, and the Mrs. actually likes the new showerhead better than the fancy-looking one that came with the new valve system I installed when I built our new master shower last year. So it’s a hit.
A savings of $40 per year goes straight to your bottom line – flowing into your ‘Stash and eventually becoming part of your retirement income through reduced living expenses. To generate this much income forever, inflation-adjusted using a 5% withdrawal rate, you would need to leave $800 permanently invested.
So just by sharing this little secret with you, I have made you $800 richer, just as the readers of the earlier article made me that much richer by sharing the same trick. Happy Holidays!
* I was planning to get the Amazon/Niagara one after reading the reviews, but I happened to be in Home Depot and saw a bin of Pfister ones at the same price. So I picked one up, figuring I could always return it if the performance didn’t match the better one I read about. But as noted, this one works great too and earns Lady approval, which is the key factor.