1. feature new sump pump design
Innovative pump solution to
storm water backup
The backup of storm water into basements and other underground building spaces during
power outages of any duration presents costly problems for homeowners. To address this
longstanding issue, US inventor Michael Ostrowski has designed and patented a new high-
efficiency water-driven sump pump that utilizes the power available in the pressure and
flow provided by the local municipal water utility. Here he discusses the market
background and existing attempts to solve the problem before providing details of the
new design and its performance.
I
AC pump solutions
n the USA and many other These AC electric motor-driven
countries, the practice of pumps are typically vertical
providing perforated drainage For those fortunate to have houses on centrifugal designs, ranging from 0.25
piping at the footing of building hills or high ground, or for those with to 0.75 hp. Most are fully submersible,
foundations has been commonplace municipal storm drains buried deep oil-filled designs installed entirely
for nearly a century. Removing ground beneath streets, this drain-piped within the sump pit. Pedestal pumps
water in this manner is essential for storm water discharges by gravity flow are also applied with more
long-term foundation stability and to to lower ground or to city-provided conventional, air-cooled AC motors,
minimize the potential for storm storm-water systems. For others on typically mounted 2-4 feet (0.7–1.3
water infiltration into below-ground flatter terrain and for those without m) above the sump cover and shaft
basements, cellars and, more municipal storm sewers, AC electric connected to a vertical centrifugal
importantly, finished living spaces motor-driven sump pumps are pump installed in the sump pit. As
(Figure 1). Additionally, removing installed in a sump pit below the long as AC power is available, these
this water prevents hydraulic pressure basement floor to eject this storm pumps provide a good solution,
under the cement floor slab, water to a municipal storm drain or cycling on demand via an electrical
Figure 1. Cellars and
underground living preventing cracking and water over the top of the foundation and float switch.
spaces are at risk
permeation that otherwise will occur. away from the building.
from infiltration by
storm water.
In the USA, homeowners experience
power outages once or twice a year on
average. Long-duration outages
exceeding 1–2 hours occur on the
average once every 2–3 years (Figure
2). In older communities, with mature
trees in close proximity to overhead
power lines, outages of both short and
long duration can occur several times
a year. Unfortunately, most of these
outages occur during severe storms
with high winds, lightening and
heavy rains, often coinciding with
high water flow rates to the sump pit.
Power outages as short as 20 minutes
or less can result in sump overflow.
Power outages of longer duration,
more than 1–2 hours or even days, can
spell disaster for a homeowner, with
thousands of gallons of storm water
backing up from the sump and into
the basement of the house, below-
ground family room, garden
apartment, or English basement. For
2 WORLD PUMPS October 2003
0262 1762/03 © 2003 Elsevier Ltd. All rights reserved

2. feature new sump pump design
rental or portable generators, rental
those with unfinished basements, driven generator with automatic start-
AC or portable pumps and other
often used for storage, work shops and up has been available for many years.
make-shift approaches for removing
play areas, the problem can be In addition to the generator itself, an
backed-up storm water.
nonetheless significant in terms of automatic transfer switch is needed to
damage and clean up. For those with protect power utility workers from the
More recently, additional factors have
only AC-powered sump pumps and no risk of ‘back feed’ during outages, so
come to the attention of many
stand-by generator, any outage with that repairs can be safely made on
insurance carriers and homeowners
rainfall can result in significant storm their system. Due to the relatively
alike such as the risk of moisture
water backup. high installed cost of $5000–$15 000
damage and high humidity levels for a small generator set, fewer than
Secondary DC throughout the building for long 1% of homes in the USA have such
systems periods of time, the possibility of mould units. Although potentially promising
contamination, health risk and the long term, fuel cells for homeowners
long-term damage to the entire
A partial remedy has emerged – the as a lower cost alternative to engine-
dwelling. The worst case in some
fitting of a second battery-powered driven generators are not expected in
homes, especially in older
DC motor driven sump pump. As long the near future.
communities, is for storm-water systems
as the battery remains well charged
and raw sewage systems to be ‘cross-
and in good condition, this additional What other possible energy sources
connected’ either in the home itself or
DC pump and battery is partially could solve this problem? Beyond
via municipal systems overburdened
effective for addressing the short battery DC pumps and generator sets,
during heavy rains. The result for the
duration outages. Actual hours of what other high reliability, unlimited
homeowner during a power outage can
operation for these DC pump and duration power sources could be used?
be raw sewage backup through the
battery packages are a function of Steam engines, engine-driven pumps?
storm water sump or underground floor
battery amp-hour capacity, pump Unfortunately cost, complexity, noise,
drains. The human toll in terms of
size/horsepower rating, motor and emissions, the need to auto start, and
financial loss, damaged personal effects,
centrifugal pump efficiency, the ‘duty safety remain as negatives as with
difficult and often messy clean up, as
cycle’, flow rate, and head of storm stand-by generators. Compressed air
well as lost time, and the surprise nature
water that must be ejected. As the DC cylinders? Unfortunately, such
of the problem remains in the minds of
motor operates and the battery compressed air storage would have to
any homeowner who has experienced
discharges, motor speed and/or torque be too large and costly overall. Solar,
this problem.
diminishes, reducing pump flow rate wind? Probably not available ‘24-7-
and/or pressure performance, 365’. Thermoelectric/thermionic
Stand-by generators
eventually fully discharging with loss converters and sodium sulfur batteries
of pump operation and storm water from the defence and aerospace
backup. To protect the DC motor, The option for a stand-by, engine- industry – fine for spacecraft and
most manufacturers of these battery
DC pump systems provide an
Figure 2. Power outages occur once or twice a year in the USA, mostly during heavy rain, lightening and high
electronic cut-off control, opening winds. On average, outages exceeding 1-2 hours occur once every 2-3 years.
the circuit to the DC motor before the
battery is entirely discharged. So even
for those with a battery-powered DC
pump, storm water backup often
occurs.
According to major homeowner
insurance companies in the USA, the
cost of both covered and uncovered
damages due to storm water backup is
US$1.5-2 billion annually, despite the
many battery DC pump secondary
systems installed to date. In addition
to the significant damage and
monetary cost of storm water backup,
below-ground flooding of homes and
other buildings represents significant
risk of injury or death for the people
involved – from falls on wet surfaces,
or electrocution as homeowners try to
resolve power problems, operate
WORLD PUMPS www.worldpumps.com 3
October 2003

3. feature new sump pump design
ocean buoys but, unfortunately, too hydraulic fluid, positive displacement lower pressure, to the sump itself, a
costly and potentially dangerous for a actuators and pumps can approach sanitary sewer, or to discharge outside
typical homeowner. nearly 100% efficiency in converting of the building.
mechanical work/energy [force ×
Water-powered distance (F.dS) or torque × angle For the case of a 4” diameter actuator
technology – high (T.dŁ)] into fluid energy [pressure × and the typical 30–50 psig water
efficiency, simple change in volume (P.dV) or volume × supply pressure, a nominal 375–625
design change in pressure (V.dP)], and back lbf up/down force is transmitted to the
again. Hydrostatic/hydraulic, positive lower 8” diameter piston, resulting in
Hydroelectric power – the conversion displacement pumps with fluid power, 7.5–12.5 psig discharge pressure from
of moving or falling water into shaft ‘hydraulic’ motor packages and the lower chambers with each stroke,
horsepower via a water turbine to run incompressible hydraulic fluids can or approximately 17–29 feet (c. 5–9
a generator – traces back to da Vinci’s achieve very high system efficiencies m) of head – more than the 10–12
water wheel itself, converting the with good design practices. feet of head required in most
momentum and energy of moving applications. With the 1:2 diameter
water into shaft torque and To better understand the present ratio of the upper versus lower pistons
horsepower. As with centrifugal invention, consider the workings of and their 1:4 relationship in areas, the
pumps, hydro-turbine efficiencies hydraulic linear actuators and positive 5–6 gallon/min (c. 19-23 l/min) flow
typically range between 40–60% with displacement, piston pumps, and that rate into the upper actuator results in
losses due to fluid turbulence, water, like hydraulic oil, is a nearly a 20–24 gallon/min gross discharge
momentum loss needed to change incompressible fluid. This new design flow rate from the lower pump
fluid direction/velocity, and fluid is essentially a ‘double acting’ water- chamber, with the device operating
friction at high velocities with driven linear actuator coupled with a with a 4” stroke and at approximately
component surfaces. linear ‘double acting’ positive 23 strokes per minute. In the lower
displacement piston pump, both with chamber, four check valves are fitted,
During the past 50 years, the very high energy conversion and conventional 1.5” diameter
piping to minimize pipe pressure drop
hydraulics industry has developed efficiencies.
and pipe friction losses.
linear and rotary, positive-
Principles of
displacement actuators to provide
operation Performance
another means of converting fluid
Figure 3. Concept power into mechanical work, but now
for the piston
with far better efficiencies. For As shown in the Figure 3, municipal For the case where the spent water from
version of the
incompressible fluids, such as water pressure and flow enter the the upper actuator is directed to the
water-driven sump
pump.
upper actuator controlled by a sump itself, the net storm water
flow valve that is designed so discharged is 15–19 gallons/min. In
as to be either ‘full on’ or’ full most cases, full 20–24 gallon/min pump
off’. The float itself is fitted performance will be possible, with the
with adjustable stops to spent actuator water having sufficient
provide for a finite on-off pressure remaining to be discharged
duty cycle, as with the float directly out of the building in parallel
switches found on con- with the ejected storm water or directed
ventional AC motor sump to a separate sanitary sewer.
pumps. On-demand, munici-
pal water pressure and flow The efficiency of the design will be
enter the self-reversing water 94–95%. With good design, O-ring
supply valve, which directs and rod seal friction will be limited
this flow and pressure stream to less than 20 lbf or approximately
to alternate sides of the 4% of the 375–625 lbf connecting
piston, reversing flow paths rod force. The only other area of
automatically as pressure rises efficiency loss is in the ports of the
in either of the chambers self-reversing water supply valve
above and below the piston as fitted to the upper actuator. This
the piston hits a stop at each efficiency loss will be limited to
end of its stroke. The water 1–2%. High efficiency is an
remaining in each chamber at important feature of the overall
the end of each power stroke design, since the spent water
is forced out of the actuator delivered to the upper actuator must
on the alternate stroke, at ultimately be discharged from the
4 WORLD PUMPS October 2003
0262 1762/03 © 2003 Elsevier Ltd. All rights reserved

4. feature new sump pump design
accommodated with a
building along with the storm water
diaphragm design for longer
ejected by the lower piston and
life and minimal or no
chamber. Further, water venturi type
maintenance.
designs are commercially available
but, due to their 40–50% efficiency,
So when and where can I buy
can consume more water than can be
one? Watch future issues of
ejected, often with rated gross or net
World Pumps and your local
discharges of less than 5 gallons/min,
hardware store or plumbing
falling far short of the 15–20
supply dealer for commercial
gallons/min that is typically required.
launch announcements. In
Design variants the meantime, try to stay safe
and dry when the lights go
out!
The design shown in Figure 1 and
described above is merely one
CONTACT
example of the many bore sizes, flow
Michael Ostrowski
rates, stroke lengths and Inventor and President,
strokes/minute of an entire family of Technology Market
Consultants
the many dimensional designs
707 Skokie Blvd., Suite 410
possible, with straightforward design Northbrook, IL 60062, USA.
relationships determining component Tel: +1 847 205 9656
Fax: +1 847 498 5712
sizes, pressure and flow rates. For
E-mail:
larger homes, or commercial m.ostrowski@tmcchicago.com Figure 4. Diaphragm variant of the sump pump shown in Figure 3.
buildings, the entire design can be
scaled up in size, theoretically,
without limit. For homes with shallow
basements, the upper actuator can be
smaller in diameter compared to the
diameter of the lower pumping
proposed
chamber, to further minimize water
consumption. As a stand-by pump
operating only during power outages,
water consumption and water cost are
quarter page
trivial compared to the avoided cost
of flooding damage.
The patent filings for this invention
advert here
(US Patent 6527518 and PCT
021/30284) include embodiments and
claims for the fitting of diaphragms to
either or both the upper actuator and
lower pumping chamber, as shown in
Figure 4. Notably, with diaphragms in
the place of both pistons and their O-
rings, the friction and efficiency loss
noted previously is eliminated.
Diaphragm flexing force will be less
than 1 lbf for each diaphragm with
this alternative design. Additionally,
the cylindrical shape and finish
quality on the inside surfaces of both
cylinders become unnecessary, and
either chamber can be shaped in
similar fashion to conventional air-
operated diaphragm pumps. Further,
the storm water that must be handled
may contain dirt, sand and other
contaminants that are better
RES No.419 – USE THE ENQUIRY SERVICE @ www.worldpumps.com
WORLD PUMPS www.worldpumps.com 5
October 2003