Pure Waste Challenge, Part II: Take Action, Go Tankless


In part two (here's part one) of our spotlight on the Pure Waste Challenge, we'll help bust a few myths about tankless water heaters and hopefully inspired you dear readers to take action against global warming. It's easy; here's how it works:
1. Read the primers.
2. Ponder the possibility of making some easy, meaningful changes in your life.
3. Send a quick email (details below the fold) to confirm that you've done both of those.

Once you click "send," the Hinkle Charitable Foundation (HCF) will donate $100 to the Solar Electric Light Fund (SELF), a very worthy non-profit working hard to simultaneously combat global poverty and climate change. It's that easy. Think about how many emails you'll send today, and consider adding one more. Hit the jump to learn more about SELF and play some fact vs. fiction with tankless water heaters.


SELF’s primary mission is to bring solar power and modern communications to rural villages in the developing world. In many instances, SELF’s installations are directed to education, health and irrigation facilities and can include joint ventures, where local participants invest in a portion of the project. Providing solar electric power to remote, off-grid people frees them from the unpalatable alternatives of either using kerosene-generated power (which is both bodily and environmentally dangerous) or living with no electricity, no lights, no irrigation possibilities, and no connection to the outside world.

The second primer is all about reducing the energy you use heating hot water by using a tankless water heater (see more coverage of them on TreeHugger here and here). Hot water usage in American households consumes between 15% and 30% of a home’s energy demand, according to the US Department of Energy. Surprisingly, the technology used to heat water in the US is antiquated and highly inefficient when compared to the tankless or on-demand technologies now used regularly in Europe and Asia. This primer attempts to explain the new technology and benefits behind whole-house natural gas-fueled tankless water heaters (TWH).

Myth 1: Only a tank can provide a large amount of hot water.

Heating a tank of hot water is neither an effective nor efficient way to supply hot water. As hot water drains from the tank, in-flowing cold water lowers the overall temperature of the water in the tank. Traditional tankbased water heaters are not designed to heat the inflowing cold water rapidly enough to keep the outflowing water at a constant temperature. In contrast, properly sized TWH systems are designed to keep outflowing water at a constant temperature.

Myth 2: A tankless hot water system can’t provide enough continuous hot water for an entire home.

The reality is that the heat-exchanger technology used in TWHs is specifically designed to provide a full and inexhaustible flow of appropriately heated water to an entire household.

Myth 3: Tankless water heaters must heat the water so hot that it is dangerous to use them.

Actually this fear is more relevant to traditional tankbased water heaters than to TWH systems. Tankless systems are safer to operate since they heat the water to only slightly above the level of intended use. Traditional tank-based water heaters have to overheat the stored water so that it will remain hot enough as the in-flowing cold water mixes with it.

Myth 4: Tankless water heating systems cost more to operate.

Like any profitable investment there is an immediate outlay of cash, but when you factor in the lower operating cost and longer (20-year) service life, TWHs save their owners a substantial amount of money. In fact, as illustrated below, it is difficult to construct a scenario where owners of a new natural gas TWH system will earn a return on investment of less than 45%.

Sounds pretty good, right? If something like this sounds worthwhile (along with the other primers that are part of the challenge, available here), we encourage you to fire off an email to purewaste(at)thehcf(dot)org with your name and e-mail address where you'd like the acknowledgment sent, and the Hinkle Charitable Foundation will make a grant to SELF. Stay tuned for the final primer, but you certainly don't have to wait for us to take action and write that email.

::Hinkle Charitable Foundation and ::SELF present the ::Pure Waste Challenge