There are a number of plumbing products on the market that claim they are green. Some are, and some probably are not. I’m going to provide my biased opinion about just how green some of these products are, then you can decide for yourself what is green and what isn’t.
First let’s define what a green product is. My feeling is that to call your product green it should either reduce the amount of energy being used for a specific task, conserve natural resources such as water, or in some other way have a beneficial impact on our environment.
One has to be careful in evaluating energy conserving, water conserving, or other types of “green plumbing products” to examine all aspects of the method or device being considered. It’s quite possible for a product to have a beneficial side and a negative side at the same time. One has to weigh both the benefits and negative aspects of a product.
I have a hypothesis about green plumbing products. I suspect they will depend heavily on user behavior to meet their goal of being green. I shall take that aspect into account in my analysis.
Years ago when I had a vested interest in the California’s Title 24 building codes to help me market an energy saving product. The CEC (California Energy Commission) had commissioned a study that revealed the human behavior problems inherent in many conservation methods and devices.
For instance, it was found that most homes did not save much energy with set back thermostats because the users were not using them properly. The study found that after installing dual pane windows, extra insulation, and making the house air tight, people would turn on the air conditioners and leave the window open, defeating virtually all the energy conservation features that had been added to the home.
Low Flow Showerheads
Low flow shower heads are a good example of water conservation devices that save water but can suffer from human behavior problems. Low flow shower heads when located far from the source of hot water end up causing a long wait for hot water, often exceeding several minutes.
Many people will turn on the shower to hot and let it run while they do something else, like make the coffee, or shave, and upon completing the task they return to check and see if the water is hot yet. When it is, it means you have not only been running precious water down the drain, but you are also dumping heated water. Heating the water uses energy and thus likely contributes to green house gas emissions, unless you are using electric water heating and are being supplied your electrical energy by a wind farm.
If, however, you are one of those environmentally conscious individuals who truly does their best to live a conservative lifestyle, then you probably will not benefit from a low flow shower head. You would probably not turn it up to full blast and spend 20 minutes in the shower. Low flow showerheads are a way of forcing wasteful people to be less wasteful.
I imagine overall it does save water, mostly with individuals like me who tend to really enjoy taking long, hot, high-volume showers. Now they are long, hot, and low volume.
I rate the low-flow showerhead a green plumbing product. Overall it saves both water and energy with minimal human behavior problems associated with it.
Low Flow Toilets
How about those low-flow toilets? I keep hearing that they finally have some that really do work well, but my experience is you often need to flush multiple times defeating the original purpose. If there are models that truly work out there then I don’t see any downside to them.
I rate the low-flow toilets as a green plumbing product, if they work. For me the jury is still out.
Tankless Water Heaters
How about tankless water heaters? They are certainly touted to be green plumbing products… they supposedly save you a ton of energy. I think we should take a closer look.
Tankless water heaters work quite differently than standard tank type storage water heaters. When you turn on the faucet and you have a storage water heater the hot water immediately flows from the water heater outlet to the fixture. The water is coming from the top of the tank where it is the hottest. As the water travels though the cold pipe, the pipe absorbs the heat from the water until it reaches equilibrium.
If your pipe holds a gallon of water between the water heater and the fixture, then it might take you a gallon and a half to get hot water due to this affect. The colder the ambient temperature around the hot water pipes the larger the effect.
Now let’s see what happens with a tankless water heater. When you turn on the fixture you are also turning on the tankless heater which has a flow switch to detect the flow of hot water and thus turn on the heater in response.
The water that immediately begins flowing thought the pipe is not hot. It has been sitting in the heat exchanger and is cold. For the water leaving the outlet to be at full temperature it must flow completely through the heat exchanger.
According to a study done by the Australian government, tankless water heaters typically require 10 to 20 seconds longer to get hot water to the fixture than storage tank type water heaters. This is obviously a negative since you will be running more water down the drain while you wait longer for your hot water to arrive. Now if your water heater is only 6 feet from the fixture it isn’t much of a problem. But if the heater is 100 feet from the fixture it is a big problem. A typical family of four can waste over 10,000 gallons of water a year waiting for hot water to arrive.
There is another water conservation problem with tankless water heaters. Remember that flow switch? It won’t turn on the hot water heater unless it detects a minimum flow rate, typically ½ gallon per minute, and ¾ gallons per minute for the larger models. This means that if you use less than ½ gallon per minute of hot water the heater will shut down. Think about that for a moment, if your fixture is 1-1/2 gallons per minute as many fixtures are, you will need to run the faucet at over half of full volume even if you only want a trickle of hot water.
Not only will you be wasting water, but heated water. Heating the water is far more expensive that the water itself. And there are the resulting green house gas releases as well. Not a very green aspect to tankless water heaters.
Human behavior is a big factor with tankless heaters. For one thing, people who like to take long showers will. That could lead to substantially higher water usage and of course, energy usage. Humans are like that.
Like with the solar industry, tankless water heaters won’t end up saving you money if there weren’t big tax incentives. When the tax incentives were eliminated for the solar water heating industry it collapsed. I think that will happen with tankless eventually as well, but that is only my opinion and I am not particularly good at predicting the future.
My opinion… Tankless water heaters are not very green plumbing products.
Hot Water Demand Systems
Hot water demand systems usually consist of a small pump mounted under the sink. The pump connects between the hot and cold water lines. When you want hot water you push a start button, the pump comes on and pumps the hot water from your water heater to your fixture at high speed. When hot water reaches the pump it shuts off to keep hot water from getting into the cold water line.
The cooled-off hot water in the hot water pipes gets returned to the water heater inlet though the cold water piping. You get your hot water faster than normal, and no hot water gets run down the drain.
Hot water demand systems will work with storage water heaters, tankless water heaters, and even solar water heaters. They run only for a few seconds at a time, just long enough to get hot water to the fixture, so they use very little energy, typically less than $2.00 per year.
Human beings for the most part do not like standing around waiting for the hot water to arrive. This means that they will usually use the hot water demand system when it’s available. It’s a convenience and humans love convenience. If they don’t push the button is the same as not having one installed.
Hot water demand systems have few if any negatives. You get your hot water faster and you save water with virtually no increase in energy consumption… what more could you ask for?
I rate the hot water demand system as a very green plumbing product.
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