by John Galcius, June 10, 2009Your Swimming Pool Carbon FootprintMy pool, an energy hog? I hardly ever hear those words used together. Because a true standard hasn’t really been set yet. National Green Building Standard does not address swimming pools, so there is not much to go by. As a matter of fact, I found out today, that an environmentally labeled “Green Home” can have a 35,000 gallon swimming pool in the backyard, a two horsepower pump running 24 hours per day, and you could still classify the home as “Green”.So, we have to “trail blaze”, so to speak. Swimming pools have a reputation for being water, electricity and in some cases, fossil fuel hogs. And that might not be far from the truth. In homes with backyard pools, more electricity is used to power the pool pump than anything else except A/C or heating system. In fact, the average California residential pool uses enough electricity during the summer to power an average home for three months.The typical backyard swimming pool holds 16,000 to 20,000 gallons of water. Pool evaporation amounts to 3 to 7 feet of water per year. For a 15 by 30 foot pool, the range is 10,000 to 23,000 gallons per year for evaporation, plus about 25% to account for splashing. If the pool is filled once a year, it requires about 38,000 gallons of water every year.Is your pool heated with a gas pool heater? The low efficiency of gas heaters result in a high cost of operation. $1.00 worth of heat requires $1.20 or more of fuel. The typical pool averages $1000 to $1500 per year for heat with propane. Natural gas is approximately 30% less. Gas pool heaters exhaust a delightful mix of pollutants and contaminants into the air.So, a typical pool can really leave a huge carbon footprint. With 7,000,000 backyard pools, that really is a dent on the environment.What Can We Do?There are so many ways to conserve energy, water and chemicals at the pool. Leaving a minimal carbon footprint is easier than you think. The following is a list of things you can do, to do your part in trying to leave as little impact on the earth.10 Ways To Reduce The Carbon Footprint On Swimming Pools1) Always cover your pool. Pool covers reduce evaporation, heat loss and chemical loss.2) Reduce the size or horsepower of your pool pump.3) Heat your pool with a solar pool heater. Or not at all.4) Avoid horseplay and excess splashing.5) Turn off waterfalls and water features when not in use.6) Use a salt chlorine generator.7) Use a cartridge filter. Cartridge filters use hundreds of gallons less than DE or sand filters8) LED lights use much less energy that incandescent lights.9) Use a pool cleaner that does not require electricity or a booster pump.10) Use a good winter cover, to avoid draining the pool.
This is really a great article. I live in MN and in our area, almost every newer pool I know of has an auto cover. These provide a multitude of benefits that I did not even expect when we built our pool...our original desire was to help neighborhood children avoid temptation while we were off at work. I've now found that though there is the initial expense of installation, the monetary proposition is at least a break even situation with reduced water maintenance and better contained heat.
Regarding water consumption, I really don't worry much about that. I find that with our cover, I only end up topping off 10 - 12 times per season. We also utilize a process to blow out lines for the winter that doesn't require any draining down. I used to work in the water/wastewater controls industry. Funny thing I learned, in the water plants I called on, they tended to worry as much about the citizenry not using enough water (reduced revenue) as they did about the citizenry using full capacity of the plant.
We just converted to a novel solar heating system this year. After studying it for several years, I chose the SolarAttic PCS3 to heat our pool. This is novel because it takes the waste heat from our attic and transfers it directly into the pool water with an air-to-liquid heat exchanger...thereby heating our pool and cooling our attic/house at the same time. This has worked really well for us. Our summer in Minneapolis has left a lot to be desired and I see over 110 degrees in the attic only a time or two per week. Even with this variability, we are maintaining mid-80's in our 20x40 pool. As full disclosure, I liked the product so much I have become a dealer for SolarAttic. PING me at greg@hotforpools.com if you are interested in learning more.
I've been investigating the IntelliFlow pumps myself. I'm seriously considering a purchase to compliment my PCS3. I love the idea of using only as much power as needed based on conditions. Are there any other options anyone would recommend?
That's right David. it is amazing, and really mind boggling how much resources pools use. As the article said, 7.000,000 pools. That's lots of water, gas, and chemicals. Not to mention the manufacturer and transport of our products we use everyday. I am trying to create a swimming pool carbon footprint calculator. It should be fun. We as professionals should start to educate our customers how, by just taking a few easy steps, we can all help to conserve, and sell a few solar blankets and solar heating systems along the way. :)
Every year swimming pools are wasting billions of gallons of water that can be saved. In areas suffering from water shortages, "It takes only 200 pools using covers to save an entire 3.5 million gallon tank of city drinking water." It's well known that pool bubble covers are inexpensive and pay for themselves by lowering your water bill and chemical costs, so why aren't more pools using pool covers?
The saltwater chlorine generator (SWG) eliminates the carbon footprint associated with regular transportation of chlorine products from manufacturers to pool store to home. This includes pH adjustment products if Trichlor is used, for example. For chlorinating liquid, the transportation footprint is higher since the chlorine is less dense (it's mostly water being transported) though there is less pH adjustment needed. There is also waste from bottles used, though these may be recycled or even reused (some pool store's reuse bottles for chlorinating liquid).
Yes, there is electricity usage generating the chlorine, but this is fairly efficient and a fraction of the "cost" associated with chlorine transportation noted above. Of course, nothing is free and there is environmental impact on manufacturing of cell plates with its special materials and there is impact with the high salt levels in the pools, especially if these are discharged.
In my own non-SWG 16,000 gallon pool, I cut down my pump electricity usage in half by replacing a 1 HP main pump and a 3/4 HP booster pump (for a pressure-side pool cleaner) with a single Pentair Intelliflo variable-flow pump plus a valve that switches the pump to a dedicated line for The Pool Cleaner that runs at 15 GPM at night. The only reason I didn't save even more on electricity is that I need to run solar panels and I have a lot of them so it takes a 48 GPM flow rate compared to the 26 GPM flow rate I use when the solar is off.
I would add to the above Reduce The Carbon Footprint recommendations to seriously consider the variable speed/flow pumps and to use larger diameter pipe to minimize head loss (within reason). I also have a cartridge filter and a pool cover and can attest to the far lower water loss and chemical (chlorine) usage.
As for evaporation, it is quite a bit higher if the pool is heated and there is no cover. For example, evaporation rates at 40% relative humidity between water that is at 70F air temperature are half that of heated water that is at 84F. I would expect that an unheated pool might have evaporation roughly equivalent to the evapotranspiration (ETo) rate of turfgrass, but that a heated pool would have a higher water loss.
The EPA WaterSense initiative views a pool, from a water use standpoint, to the equivalent of the same amount of area planted in high water requirement turfgrass. The number of gallons this equates to varies depending on the climate of where you live. Do your figures for evaporation account for some replenishment via rain? Loss due to backwashing filters?
I am not sure how a salt chlorine generator minimizes the carbon footprint, especially since it runs on electricity 8-12 hours per day.
Comments
Regarding water consumption, I really don't worry much about that. I find that with our cover, I only end up topping off 10 - 12 times per season. We also utilize a process to blow out lines for the winter that doesn't require any draining down. I used to work in the water/wastewater controls industry. Funny thing I learned, in the water plants I called on, they tended to worry as much about the citizenry not using enough water (reduced revenue) as they did about the citizenry using full capacity of the plant.
We just converted to a novel solar heating system this year. After studying it for several years, I chose the SolarAttic PCS3 to heat our pool. This is novel because it takes the waste heat from our attic and transfers it directly into the pool water with an air-to-liquid heat exchanger...thereby heating our pool and cooling our attic/house at the same time. This has worked really well for us. Our summer in Minneapolis has left a lot to be desired and I see over 110 degrees in the attic only a time or two per week. Even with this variability, we are maintaining mid-80's in our 20x40 pool. As full disclosure, I liked the product so much I have become a dealer for SolarAttic. PING me at greg@hotforpools.com if you are interested in learning more.
I've been investigating the IntelliFlow pumps myself. I'm seriously considering a purchase to compliment my PCS3. I love the idea of using only as much power as needed based on conditions. Are there any other options anyone would recommend?
Yes, there is electricity usage generating the chlorine, but this is fairly efficient and a fraction of the "cost" associated with chlorine transportation noted above. Of course, nothing is free and there is environmental impact on manufacturing of cell plates with its special materials and there is impact with the high salt levels in the pools, especially if these are discharged.
In my own non-SWG 16,000 gallon pool, I cut down my pump electricity usage in half by replacing a 1 HP main pump and a 3/4 HP booster pump (for a pressure-side pool cleaner) with a single Pentair Intelliflo variable-flow pump plus a valve that switches the pump to a dedicated line for The Pool Cleaner that runs at 15 GPM at night. The only reason I didn't save even more on electricity is that I need to run solar panels and I have a lot of them so it takes a 48 GPM flow rate compared to the 26 GPM flow rate I use when the solar is off.
I would add to the above Reduce The Carbon Footprint recommendations to seriously consider the variable speed/flow pumps and to use larger diameter pipe to minimize head loss (within reason). I also have a cartridge filter and a pool cover and can attest to the far lower water loss and chemical (chlorine) usage.
As for evaporation, it is quite a bit higher if the pool is heated and there is no cover. For example, evaporation rates at 40% relative humidity between water that is at 70F air temperature are half that of heated water that is at 84F. I would expect that an unheated pool might have evaporation roughly equivalent to the evapotranspiration (ETo) rate of turfgrass, but that a heated pool would have a higher water loss.
I am not sure how a salt chlorine generator minimizes the carbon footprint, especially since it runs on electricity 8-12 hours per day.