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GOODWORKS
For most Albertans, keeping warm during the evening is as simple
as turning up the thermostat. Not so in the Guatemalan Highlands,
2,600 metres above sea level, where an open fire on a dirt floor is a
common choice. Even if the flames don’t hurt family members, the
toxic smoke they breathe probably will.
It’s a serious health and safety problem in Guatemala and many
other developing nations. A group of University of Calgary engineer-
ing students, however, came up with a simple and inexpensive solu-
tion, working in collaboration with a small not-for-profit in Calgary
called Help for the Highlands of Guatemala, or HFHG.
The students’ creation is a heat exchanger called the Chinook.
Existing high-efficiency stoves get smoke out, but on their own they
don’t do much actual heating of a home. Add the Chinook and the
problem is solved.
How did the students get to this point? Rewind to 2007. Two
Calgary professionals are looking for a way to use their skills
and experience to improve the living conditions of impoverished
families in Central America. Together they form HFHG, which
works to supply clean water, sanitation and high-efficiency stoves
— ecoplanchas — to families in the mountainous Mayan village of
Quiacquix, population 1,300.
Over the past three years, volunteers with Help for the High-
lands have installed ecoplanchas in 150 Quiacquix homes, replacing
the traditional — and unvented — three-rock cooking fires used in
three-quarters of the region’s homes.
“We were initially focused on water, but when we went there,
we quickly realized there is really a need for stoves because of the
respiratory deaths that were being caused by the open fires. It’s one
of the leading causes of death for the Mayan women and children,”
says Alan Sitter, P.Eng., cofounder of HFHG.
It’s a problem not only in Guatemala but in millions of homes
across the developing world. The World Health Organization esti-
mates that smoke from indoor cooking fires — which creates car-
bon monoxide and other noxious fumes — works out to two packs
of cigarettes smoked a day per person and causes numerous health
problems. Women and children are more likely to breathe the smoke
and are especially vulnerable to chronic respiratory illness, tubercu-
losis, eye infections, pneumonia and burns.
Student Design Addresses Deadly Heating System
Sitting around a fire for tea or a meal might seem like a foundation of happiness, but in some developing
countries the technology people use to stay warm — open fires on a dirt floor — is literally a killer. A design
project by six University of Calgary engineering students, however, creates a safer, healthier heating system
for families than one that poisons the air they breathe
BY CORINNE LUTTER
Member & Internal Communications
Coordinator
Each concrete ecoplancha has an oven core made of brick, a
flat-iron top and a steel chimney, and removes 99 per cent of smoke
from the house. As an added benefit, ecoplanchas burn 70 per cent
less wood than an open fire, saving families money in fuel costs
while reducing air pollution and deforestation.
Problem solved, right? Not so fast.
Upon return visits to see how the stoves were working, Help
for the Highlands volunteers discovered a perplexing conundrum.
“The ecoplancha stoves are really designed to be used in a
warm climate. But it’s cold up there in the highlands and the people
have no heat in their homes,” says Mr. Sitter. Nighttime tempera-
tures can drop to around 5 C.
“Because the stove we install is so efficient, it does not heat
up their homes. So people continue to build three-rock fires to
heat their homes — even after the vented ecoplancha stoves have
been installed,” he says.
A retrofit was in order. “What we were looking for was a heat
exchanger to go onto the flue pipe so families can sit around the
stove and stay warm at night,” says Mr. Sitter.
But even though thousands of the ecoplancha stoves are in-
stalled by not-for-profit organizations each year, he could find no
existing products on the market that fit the bill. “Why hadn’t some-
body already built something? Because with non-governmental
organizations, you don’t have money and you don’t have time.”
REAL-WORLD SOLUTIONS
A mechanical engineering graduate from the University of Calgary’s
Schulich School of Engineering, Mr. Sitter started mulling over the
involvement of his alma mater. How might creative young minds
in the Department of Mechanical and Manufacturing Engineering
approach the problem?
Each year, fourth-year students put their skills to the test by
working on real-world design challenges. Local organizations are
invited to submit proposals, so that’s just what Mr. Sitter did.
Many students, including Jane Leung, now an E.I.T., applied to
work on the retrofit.
“I think we had around 30 projects to choose from,” says Ms.
Leung. “I ranked the heat exchanger project as my first choice

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and I was lucky enough to get it. I thought
it would be great to help out a non-profit
organization and make an impact.”
So did fellow students Sean Connors,
E.I.T., Asad Dandia, E.I.T., Brian Kemball,
E.I.T., Nishant Patel and Maulin Trivedi.
They all put their names forward and were
selected for the unique opportunity.
Says Mr. Dandia: “As a soon-to-be-
engineer, I think it’s important to use our
knowledge to develop innovative ideas, while
providing sustainable products for individu-
als who need it most. The ecoplancha heat
exchanger that we designed does both.”
For Ms. Leung, who had just finished
a 16-month internship working on the
installation of a gas plant heat exchanger,
it was also a chance to apply her skills in a
completely new setting. “That’s part of the
challenge that I love about engineering —
that’s it applicable outside of your industry.
You can look at Third World issues and
apply what you know to help organizations
like Help for the Highlands.”
DOWN TO WORK
Work on the project began last September.
The students had two semesters to design
and build a working prototype. They started
by consulting with their sponsor to get a
handle on the issue and find out their design
parameters.
Their objective: design an economical,
efficient and safe heat exchanger capable of
using heat escaping through the ecoplancha
flue to provide warmth to the occupants of
the house.
To be successful, the heat exchanger
had to
• cost about $15 to build
• be retrofittable to existing stoves
• be easy to operate
• not inhibit cooking
• not leak smoke into the home
• operate under repeated use with mini-
mal maintenance
• prevent accidental burns or cuts
• be quickly installable using conventional
tools
• be built and sourced locally with minimal
materials.
The environment the heat exchanger
is used in was also an important consider-
ation: it would need to heat a home about
FROM FIRE TO STOVE — PART OF THE SOLUTION
Many families in the Highlands of Guatemala cook meals using traditional three-rock fires (left), which leads to respiratory illness and burns. High-efficiency ecoplancha stoves
installed by Help for the Highlands of Guatemala (right) reduce health and safety problems, but don’t provide enough heat to keep families warm at night.
-photos by Alan Sitter, P.Eng.
“There’s a whole bunch of these stoves all over the
world and they all have the same problem in locations that get quite
cold during the evening. This could have a global impact if it is
successful, so that’s pretty amazing — I didn’t think a fourth-year
project could have that big of a potential impact” JANE LEUNG, E.I.T. Team Leader

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GOODWORKS
4.5 by six metres in size, made of adobe bricks with a clay roof.
It was assumed that some heat would be lost through leaky win-
dows and doors, and that the average outside temperature was
12 C. The goal was not to heat the whole home but to warm oc-
cupants as they gathered around the stove for their meals or for
evening tea.
After several meetings and much emailing with Mr. Sitter, the
team got down to the business of brainstorming.
“We had a lot of goals originally. We considered using solar
powered fans — we really wanted that forced convection, a lot more
typical for heat exchangers,” says Mr. Kemball. “We tried to find out
if other NGOs would provide solar panels, so we could have fans
driving air, but that increased costs a little too much.”
Shell-and-tube, flat-plate and air-to-water heat exchangers
were also considered — even heat-retaining bean bags.
After meeting with their project adviser, Dr. Abdulmajeed
Mohamad, P.Eng. — a heat-and-mass transfer expert — the team
opted to simplify their design into a thin, flat-plate exchanger that
uses natural convection to maximize surface radiation.
Rectangular and cylindrical designs were considered, but
several drawings and three prototypes later, the rectangle won
out. The cylindrical design took up too much space and was
too expensive to build; while the rectangular design was more
affordable and created a larger surface area to radiate the heat.
“One of the big things on reducing costs is to make sure
that the heat exchanger can be cut economically from the four-
by-six-foot sheet metal they use in Antigua, where the stoves
are manufactured. They have simple machines that can just cut a
straight edge, and hand tools to cut all of the detailed tabs,” explains
Mr. Kemball. (Antigua is a city within the highlands.)
The team refined the design through a series of experiments
testing various hypotheses. What effect would circular or staggered
baffles have? Would black paint help increase external surface
temperatures?
The students didn’t have an actual ecoplancha stove to work
with, but they did have a lab with a heater.
Says Ms. Leung, the team’s leader: “We tried different
configurations of flue pipes on a heater in the engineering building’s
testing facility. We simulated smoke, basically, coming out of the
ecoplancha stove with hot air with the same temperature and
flow rate. We did a series of tests, and in the end our experiments
showed us that a flat-plate exchanger would be the best and would
meet our design parameters,” says Ms. Leung.
During experimentation, the temperature of the inlet and outlet
flows was measured. The flat-plate heat exchanger captured about
29 per cent of the heat entering the flue, or about 522 watts.
The final product is a thin duct that replaces the stove’s
four-inch flue pipe and connects to an existing cylindrical elbow.
“This was not an easy project —
their professors really pushed
them. They had to do a lot of
research because there’s not a lot
of published data on this. I think
it’s fantastic that a group of young,
future engineers took this task to
heart. They could have taken on
projects for large companies that
would most likely have helped
further their careers. However,
they chose to spend their time on a
project for NGOs, to help the native
people in a developing country.”
ALAN SITTER, P.ENG.
Cofounder
Help for the Highlands of Guatemala

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THE MISSING LINK
From left, Jane Leung, E.I.T., Maulin Trivedi, Brian
Kemball, E.I.T., Nishant Patel, Asad Dandia, E.I.T., and
Sean Connors, E.I.T., pose with their flat-plate heat
exchanger, the Chinook, at an April design fair. When
ecoplanchas are retrofitted with the Chinook, they can
be used as heaters as well as stoves.
-photo by Alan Sitter, P.Eng.
MORE INFO
hfhguatemala.wordpress.com.
The only installation requirements are
to remove the current flue pipe from the
elbow up, then exchange it with the new
design.
“It takes the heat from the smoke and
basically radiates it out of this metal box —
the heat exchanger,” says Ms. Leung.
Each unit is built using
• sheet metal for the main body of the flue
• ventilation adapters
• black spray paint to increase thermal
radiation
• silicon sealant to prevent smoke leakage
• sheet metal screws to hold down
flanges
• chicken wire to prevent users from
touching the hot surface.
The final product meets all the original
design requirements — except cost. Per
unit, the total ended up being $20.65, but
the team is hopeful that materials will be
cheaper in Antigua and that bulk buying will
help drive the price down.
WARM WINDS OF CHANGE
In mid-April, the students presented their
finished product at a student design fair.
The symbolic name of their creation is
Chinook, for those famous Rocky Mountain
winds that sweep across the Prairies and
cause a rapid rise in temperatures.
“This warm rise in local temperature
is exactly what we want to happen with
the heat exchanger when it is used in the
Highlands of Guatemala,” says Mr. Sitter.
He travelled to Guatemala over the summer
to retrofit eight stoves for a six-month pilot
project, working with several local partners
on manufacturing and installation.
He’s especially pleased with the
students’ hard work and enthusiasm, and
the support from their professors and the
Schulich School of Engineering.
“This was not an easy project — their
professors really pushed them. They had
to do a lot of research because there’s not
a lot of published data on this,” says Mr.
Sitter. “I think it’s fantastic that a group of
young, future engineers took this task to
heart. They could have taken on projects for
large companies that would most likely have
helped further their careers. However, they
chose to spend their time on a project for
NGOs, to help the native people in a devel-
oping country.”
If the pilot project is successful, Help
for the Highlands will share the design with
other NGOs, especially those operating
in cooler climates. “It will be free, open-
sourced to anybody in the world who wants
to use it,” says Mr. Sitter.
In the Highlands, thousands of stoves
could be upgraded, and new stoves every-
where could be manufactured with the heat
exchanger built right in.
“There’s a whole bunch of these stoves
all over the world and they all have the
same problem in locations that get quite
cold during the evening. This could have a
global impact if it is successful, so that’s
pretty amazing — I didn’t think a fourth-year
project could have that big of a potential
impact,” says Ms. Leung.
All six students who worked on the
heat exchanger graduated in April and are
embarking on new careers with various
engineering companies, but their experience
with Help for the Highlands won’t soon be
forgotten.
“We’re all going to be staying in
contact with Alan (Sitter) long after we’ve
graduated to see how this turns out,” says
Mr. Kemball. “It’s pretty exciting to be able
to see this project through all the way to
completion.”