Rain water collection is used to harvest water for
showering and general hygiene purposes.
The roof and four awnings collect rain water. A gravity fed gutter system moves the water from the
gutters to water storage pillow below the house. A small pump
pushes the water through a 4-stage filtration system and into a pressurized
intermediary tank near the roof of the house. This intermediary tank feeds into
a hot tank heated by a solar energy.
Pipes coming from the cold and hot water tank unite in a water mixer
that connects to the shower head.
Estimations of the water usage for a Tiny House owner
Rain water in the house is primarily
used for showering, brushing teeth, shaving, and hand washing. The daily usage is estimated at the
lower end of national averages, assuming that an individual deciding to live in
a tiny house will be interested in conserving resources. Showering usage is lowered
significantly due to the low flow shower head.
Rain data from the past five years
in Chicago, roof size, and usage determined the water tank size and awning size
needed. The roof has to collect
enough water to sustain about 7 gallons a day to fulfill the user’s desired
usage. Since, rainfall does
not occur daily, a water tank needs to hold water from heavy rainfalls to
provide water for dry spells. A 400 gallon water tank removes the possibility of days with no water. However, to maintain enough water in
the tank for usage, the rain water collection catchment area of the home is increased
from 128 square feet to 320 square feet.
Awnings attached to the roof
on all sides provide an additional 200 square feet of horizontal rain water
collection area. See figure for
sizing of all awnings.
The awnings are made from a
high grade, darkened vinyl that does not degrade from UV light and promotes
snow melt. Aluminum lightweight and
rigid frames extend from the sides of the house to support the awning. As pictured here, the awning on the
south side allows light to enter in the winter, reaching the back wall during
the winter solstice. The light
does not enter the house during the summer, keeping it cool.
The vinyl awnings can be taken
down during travel to fit the highway criteria. The steel frame can disassemble and store in the home for
Awning sketch showing Sun angles during different seasons of the year.
A gutter feed system
transports collected roof and awning water through a pre-filter, removing
organic debris, and into the water pillow. The pre-filter sits slightly above the gutter line, allowing
for natural water flow, but removing leaves, twigs, plant debris. The pre-filter is made of 50% recycled
material and has no chemical leaching. The gutters are stationed on the outside of all four awnings
at varying heights; all the water feeds into a downspout gutter on the
southeast corner of the home via gravity.
The gutters are made from lightweight aluminum material and can be
easily disassembled during travel.
The water is stored in a
flexible water tank, called a water pillow. The pillow is custom-made to fit under the trailer and in
between the wheels. The pillow and
all accessories are placed in an insulated box to prevent freezing and damage
to pumps and pipes.
The pillow will be approximately 7'x14'x1'
and hold up to 400 gallons of water, providing enough water to last through dry
During travel, the pillow is
drained and taken out. The pillow is disconnected from the
pipes and folded up for travel.
Water is pumped from the water
pillow, through the filters, and into an intermediary tank above the shower
head. A pump delivers water
at 2GPM, significantly higher than the 0.5225GPM needed for the shower
head. As the water flows through
the filters and up the pipes, the flow decreases. The pump also needs to deliver at least 25 psi to successful
elevate the water to the intermediate tank, provide enough pressure to activate
the on-demand water heater, and
supply good pressure for the shower head .
A four-stage filtration
process cleans the rain water. The
system includes a sediment pre-filter, granular activated carbon pre-filter,
carbon block pre-filter, and a UV light disinfection chamber. The filters
successfully remove organic debris, contaminants, impurities, and disinfect the
water. Additional chlorination can
be used for improved scent and residual effects of reducing pathogenic
microorganisms. The filter system is
2' x 2' x 6" and is stored in the interior of the home above the
pump. The UV light requires
16 watts (depending on flow).
The water from the pump enters
an intermediate pressurized tank. The tank holds 10 gallons of cold water with a
4 gallon drawdown. The pump only turns on when the water is below the
drawdown value. Without the tank,
the pump would be activated every time the faucet turns on, decreasing its
lifespan. The pressurized tank also
maintains a constant pressure and does not allow large and dangerous spikes in
water pressure. The pressure in
the intermediate tank is controlled by a pressure gauge and can be set to push
water from the cold water tank to the lower pressure hot water tank. As shown in the picture, water is kept
in a bladder and air pressure pushes on the bladder from the top. The pipe from the cold to hot water
tank is curved to allow cold water to enter at the top of the tank and already
active solar heated water to enter into the mixer.
Picture source: http://www.inspectapedia.com/
Solar Water Heater
An active solar water heater
uses a glycol fed heat exchanger and small pump to heat the water in a 20 gallon insulated tank. This water
is fed into the on demand water heater.
Shower Head and Mixer
The cold water pressure tank and
water from the on-demand water heater feed into a shower mixer. The mixer maintains a constant
temperature (set by the user) by using a pressure sensor to ensure an equal
mixing of the different water lines.
This water feeds into the Bricor 110 Ultramax showerhead, which uses a
A non-electric composting toilet reduces water
consumption in our home. The
toilet holds waste in a chamber below the toilet seat, allowing the feces to
biodegrade into humus. A
ventilation vent and fan move air away from the chamber to help composting and
remove odors. Urine is collected
through a separate pipe and sent out of the home.