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Jonathan Bushman

posted Jan 5, 2011, 1:24 PM by ASHRAE Saskatoon
Interview with Rob Dumont

If you have lived in Saskatoon for a while and you are reading this, then you have probably heard of Rob Dumont.  I am quite sure that I heard of Rob Dumont before I heard of ASHRAE and I probably heard of Rob Dumont before I knew what HVAC meant.  In fact, my wife, some friends, and I went on a tour of the VerEco energy efficient home at the Western Development Museum and Rob’s name popped up again.  Rob Dumont has been famous for his knowledge of building science and energy conservation for years.  I had an opportunity to interview him about his career in the fall of 2010 and here is what I learned.

Rob Dumont has had a varied career.  Rob has a Ph.D. in mechanical engineering and more than thirty years of experience in the building energy field.  Rob has been a lecturer at the Kenya Polytechnic in Nairobi, a sessional lecturer and research associate in the department of mechanical engineering at the University of Saskatchewan, an associate research officer with the National Research Council of Canada, and a researcher with the Saskatchewan Research Council.  Rob’s career has included working on the Saskatchewan Conservation House in 1977, the HOTCAN (or HOT-2000) software for residential energy analysis, and the Canadian Model National Energy Code for Buildings.  Rob is now a principal with his own company, Dumont and Associates, specializing in building energy efficiency and envelopes and indoor air quality.

Rob Dumont started his career as a lecturer at the Kenya Polytechnic, which was a technical school like Kelsey, but has now become a university.  When Rob started there, he was, in his own words, “green out of UBC”.  Nairobi has a benign climate, with temperatures ranging from 11 to 28 degrees Celsius.  Generally, if the building design is good enough, with careful attention to orientation, shading, and cross-flow ventilation, then you do not need mechanical space heating or cooling.  Rob mentioned that building design in Nairobi was unfortunately starting to use European technologies (like curtain walls) that were inappropriate for Nairobi’s climate because of the very high solar heat gains.  While at the Kenya Polytechnic, Rob taught using the City and Guilds curriculum (from Great Britain), which was fairly advanced for the time.  The curriculum allows for training to become a technologist as well as further studies to become an engineer.  Exams were administered externally.  Rob mentioned a new school for the deaf in Tanzania that was designed to control heat gain.  In making the school, the designers had oriented the layout of the buildings and classrooms so the teachers would not create shadows on the blackboards that would hide what they were writing in the naturally lit classrooms. These design principles are some of the lessons lost as we forget how and why things were done in the past.

Rob Dumont has several years working for NRC, the National Research Council of Canada, studying energy conservation and air tightness.  Windows and doors were suspected to be major sources of air leakage, but, in general, windows and doors only accounted for an average of roughly 20% of the air leakage.  Much of the air leakage was occurring at interfaces (e.g. between the wall and the floor and the wall and the ceiling).  This may explain why some people would find bats and squirrels in the attic.  Rob worked with Harold Orr at NRC and described him as an engineer who was excellent at devising practical methods for air sealing.  At that time in the late 1970s, air tightness had been somewhat ignored in the field of HVAC as there were computer programs that would generate conduction heat loss calculations with answers to six significant figures and yet people would take a rough guess at the air leakage in ACH (Air Changes per Hour).  During air leakage testing at NRC, Rob would use tracer gas, like sulfur hexafluoride.  Rob’s research also focused on low energy homes.

Rob currently has a project working with the International Energy Agency.  They are using the Dumont residence in Saskatoon as a testing laboratory examining space heating load shaving.  The project also involves district heating.  In Saskatoon, the University of Saskatchewan and Innovation Place each have district heating systems.

When asked about his favourite projects, Rob Dumont said his favourite was the Dumont residence.  He was able to do the work himself without having to work for anyone else and it is his home.  The Dumont residence has a detached garage with a South sloping roof and Rob would like to install a photovoltaic system on it sometime as he figures he needs about 10,000 kWh / year of electricity to make the house net zero in annual energy use.  Future upgrades include better (more energy efficient) lights and appliances.  Rob mentioned that the VerEco home (currently on display at Saskatoon’s Western Development Museum) uses low wattage light emitting diode (LED)  lamps for pot lights.  The Dumont home was once described as the best insulated house in the world at the time it was built in 1992.  (See the May / June 2000 issue of the Home Energy magazine.)  The Dumont residence has the following insulation levels: R80 in the roof / attic, R60 in the walls (including basement walls), and R35 in the basement floor.  The Dumont residence was designed to minimize air leakage.  Rob also liked working on the Factor 9 home and the VerEco home.

Making a single house into a Net-Zero Energy Building (NZEB) is one thing, but can it be done with a neighourhood?  Rob said it was doable.  In fact, there is a block of residential buildings in Slough, England that is doing just that.  Several apartment buildings are linked via a centralized heating system and work together as a net-zero energy complex.  A neighbourhood may have space restrictions that could limit the choice of technologies used.  Rob said that photovoltaic electricity is not currently economical around here, but as the cost of photovoltaic systems goes down and SaskPower rates increase, then it may become economical.  Wind power is a mature technology and fairly well known.  Rob suggested that a NZEB neighbourhood could make a contract with a wind developer for the power supply.  Alternative energy options include biomass.  In Ontario, biomass pellets are sometimes used as an alternative for coal.  A biomass system needs a steady supply of biomass.  Rob mentioned that carbon credits were currently trading at about $20 per ton in Europe and said that they should be trading at $200 per ton to provide a motivating factor.  If carbon credits were $200 per ton, Rob estimated that the cost of electricity would double in those areas using coal for electricity generation.  Rob was asked if he sees the possibility of office towers being NZEB in 50 years.  Rob replied by mentioning that the AIA (American Institute of Architects) has called for all new buildings to be NZEB by 2030.  That would include office towers.  Rob said the principle for getting buildings to net-zero energy is to “First, reduce the demand.”  Then use green energy sources.  Wind power is attractive, then biomass and photovoltaic (PV).  GE (General Electric) is getting into PV and even provides electric cars for some of its staff.  Net-Zero Energy Buildings are becoming a reality.

When asked if he had any advice for students, Rob Dumont referred to Wayne Gretsky’s phrase: “Go where the puck is going to be.”  If you are in engineering, then work for a company where engineering will be important.  Seek out firms of interest, and not places that have a large starting salary.

In looking to the future, Rob pointed out something Tom Watson (ASHRAE Fellow and Current Treasurer) said: buildings account for 40% of energy use.  We need to move toward sustainable buildings and have NZEB (Net-Zero Energy Buildings) as the norm.  Forty years ago in Kenya, they were doing electrical load management with water heaters and peak shaving (moving energy use to non-peak times).  Our energy supply is based on fossil fuels and we need to quickly move to renewable energy sources.  If the cost of electricity increases noticeably, then people will get thinking about where we can cut back on energy use.  California uses less energy than Canada, roughly half the electricity per person, including industrial use.  We need to reduce our energy use.  Air tightness and insulation levels matter.  We need to orient buildings to control solar heat gain.  Rob mentioned that West facing patio doors are particularly bad for overheating in the warmer parts of the year.  NZEB is an ideal, like a frictionless plane, but we can go beyond NZEB with buildings exporting energy.

Rob Dumont concluded the interview by saying that engineers have responsibilities.  We have a duty to serve the public, to consider climate change and decrease the use of fossil fuels.  Engineers must solve the problems and not be driven by “bean counters” that worry mostly about first costs and ignore life cycle costs including environmental damage caused by our choices.  The costs of not considering the environment outweigh the financial costs.

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