DYNAMO CUTS
ENERGY-WATER-EMISSIONS-COSTS BY 50%
The Importance of Green &
Clean Technologies for Indoor Swimming Pools
Recycling - Commercial
swimming pools are by design highly efficient water recycling
systems. Generally using chlorine and automated pH/ORP
controllers, commercial year-round indoor pools operate under
infinitely variable conditions, including swimmer load factors
ranging from dozens to thousands per day. Keeping this water
continuously clean and healthy is what well-run pools are all
about. It is recycling the water efficiently to filter and
oxidize all forms of contaminants. Depending on how well the
chemical balance is managed, a pool may operate for 10 years
without essentially changing this water. However, due to high
rates of evaporation, considerable fresh make-up water must be
added.
Evaporation - Because heat loss
is integral to the physics of evaporation, indoor pools are
constantly working to maintain fresh, healthy air with proper
ventilation, while simultaneously trying not to exhaust undue heat
out of the building. Evaporation requires huge amounts of
energy loss to occur, resulting in water loss, humidity gain,
chemical loss, and possibly increased corrosion. Dynamo is a
big energy consumer with its six pools needing to be heated year
round, so we have undertaken a big energy savings project with the
idea that what’s good for the environment must also be good
for us financially. The fundamentals of this project are
alternative energy (solar) and energy conservation (pool
blankets). The objective has been to cut energy and water
consumption. Only with hindsight have we realized how
successful our efforts have been.
Environmental - Call it green,
call it eco-transformation, consider it Dynamo’s contribution
to reducing global warming. Dynamo has become acutely aware
of the need, particularly for indoor swimming pools to integrate
alternative energies and energy efficiency practices. And we
have successfully put these objectives into practical
practice. Here’s the magic unique to indoor
pools. The problem for any alternative energy technology is
what to do about energy storage and retention. What Dynamo
has discovered and been validating over the past four years is that
our pools, with nearly 2 million gallons of water, have remarkable
storage capacity for heat (Btu’s). The
“magic” is two forms of pure physics. One is
alternative energy creation using solar thermal panels covering our
rooftops. The other is real energy efficiency using pool
energy blankets to cover all water surfaces at night.
Creating a vapor barrier and covering the water surface actually
stops the transformation of water from a liquid to a gas, otherwise
known as evaporation. Same principle as putting a top on a
teapot. This blanket prevents evaporative cooling (70%) and
ventilation/air movement (27%) which account for roughly 97% of an
indoor pool’s total heat loss on a year round basis.
Energy - Another analogy
- leave one cold pot of water on the counter, leave another
pot of boiling water on the stove. Study the difference in
the rates of evaporation. The hot pot evaporates its heat and
water much, much more quickly. This same relative physics
phenomenon happens with our heated pools. All temperatures
naturally seek equilibrium. The greater the temperature
differentials, the greater the rate of change. Warmer pools
evaporate faster and in greater volumes. The colder and drier
the outdoor air, the greater the evaporation differential.
Nighttime temperatures are always colder, so the rate of
evaporation at night is greater. The longer and more
efficiently you cover the water surface, the less evaporation can
occur, and the less heat is lost.
Dynamo pools are maintained at a year-round temperature of
80-degrees (competition) or 86-degrees (training). When
generally the outside air temperature drops and as the relative
humidity drops, the amount of evaporation increases. On a
rainy day, rising humidity may virtually stop evaporation.
Contrary to general opinion, the greatest amount of evaporation
does not occur on hot summer days, it occurs in greater volume on
cold dry winter nights.
Outdoors around Atlanta, its pools, lakes, or waterways all lose an
average an average 50 inches of surface water to evaporation per
year every year. But as water temperatures and air
temperatures equalize, evaporation is slowed. Factoring in
wind (air movement), the evaporation loss outdoors in Atlanta is
more like 1-1/2 inches per week annualized. However, indoor
pools will create even higher evaporation losses in the
neighborhood of 2 inches or more per week. This is due to
generally higher temperature differentials between the warmer pool
water and the colder nighttime outside air temperatures in fall,
winter, and spring seasons.
Big Renewable Energy & Really Big Energy
Efficiency - Dynamo believes it has
conducted the largest “natatorium energy conservation
study” of its kind in the U.S. employing both alternative
energy creation (27,000 square feet of solar panels) and energy
efficiency (28,700 square feet of pool blankets) over the past four
years. Our objective was to gain a better understanding of
evaporative heat loss and to track complex climate variables and
difficult-to-monitor evaporation conditions. We simply took a
baseline year (2002), an energy project launch year (2003), and
then tracked utilities consumption (gas and water) for the next
four years (2004 – 2007). What we found surprised
us - solar, with a capital investment of $210,000, only
contributed 30% of annual savings. However the blankets,
which cost $25,000, actually accounted for 70% of total
savings. For the past four years, natural gas consumption was
reduced by an average of 139,000 therms and water conservation has
been reduced from 9 million gallons to 4.6 million gallons
annually.
Economics - Saving money has
been the biggest driving force. In summary, Dynamo has
managed to cut natural gas heating consumption by 50% and water
consumption by 50%. As indicated, roughly 30% of the total
energy savings came from alternative energy, the solar thermal hot
water heating systems employed on each pool. But an amazing
70% of total energy savings comes from improvements in energy
efficiency or conservation of existing heat. Just as with
preventing heat loss, 100% of water savings comes from stopping
evaporation using pool energy blankets 7 hours each night.
Total financial savings each of the past four years for our five
pools has averaged close to $200,000 for gas, $27,000 for water,
and $10,000 for chemicals. Cumulative four-year savings are
about $950,000.
With the opening of our 6th pool in Alpharetta, savings for the
coming year are projected to be $300,000. Our attention to
managing the combined solar and blanket energy programs more
efficiently is clearly a high priority. This $300,000 is a
direct bottom line cost savings to our operating budget every
year.
Emissions - With the 50%
reduction in gas consumption comes a 50% reduction in CO2
greenhouse gas emissions. While energy conservation efforts
reduce consumption by 139,000 therms yearly, this means 1.6 million
pounds (812 tons) of CO2 are eliminated every year. The U.S.
EPA calculates this as being equivalent to taking 142 passenger
cars off the road each year. Or the equivalent of carbon
sequestered by 19,000 tree seedlings grown for 10 years. From
an environmental standpoint, we feel this emissions achievement is
an enormous contribution indoor swimming pools can make toward
directly reducing global warming and setting a positive example for
the community.
Green & Clean - Dynamo
members see themselves as a new breed of green investor, promoting
their small part in improving the swimming world while also
improving the global environment. Dynamo is proud to have
developed substantial achievements in multiple areas -
water conservation, alternative energy creation, energy efficiency,
energy storage, and emissions reduction. In the scheme of
things, this has been a pretty big energy savings achievement and
financial windfall. Perhaps the cutting edge of improving
natatorium operations.
Bottom Line - We have invested
our own money, no subsidies, no incentives, no grants, and no
rebates. Along with our desire to be responsibly green, we
made it work financially. We have adapted a simple solar
heating technology. And we have developed our own ultralight,
vapor barrier, energy blanket materials and innovative handling
system technologies. We paid back the original capital
investment of $235,000 in a little more than a year as utility
savings were realized and energy costs began to skyrocket.
Payback on blankets alone is less than two months. Now each
year’s annual savings of $250,000 to $300,000 goes straight
to the bottom line. A great way to prevent offsetting dues
increases. A great way to run your business smarter.
This green & clean energy project has been a great challenge,
yielding energy performance and financial benefits far beyond
expectations. We have clearly proven that solar hot water is
viable, but the greater impact of energy efficiency using pool
energy blankets for indoor pools should be top priority because it
yields exceptional economic and environmental returns.
It’s the kind of change in our operations and management
philosophy that allows us to compete on a whole new level
- and become a unique energy example for natatoriums
nationally and globally.
Conclusion - Indoor pools cannot afford
not to use energy blankets. This isn’t exactly about
saving the environment. Foremost, it makes good business
sense, and it is financially-driven. It is all about
rethinking energy efficiency to consistently save big money year
after year by reducing operating expenses. Saving energy and
saving water are by-products of saving money.
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