Harold Orr reflects on why the Saskatchewan Conservation House was a landmark on the road to high performance buildings.
Interview with Harold Orr
Following his father and grandfather, Harold trained as a carpenter. From the age of 12 he had already spent a lot of time on building sites learning about the industry. After a 2 year spell reading mechanical engineering at university he met his future wife, dropped out of university and returned to carpentry. However, an opportunity arose to forge a career in architecture for a few years before returning to Saskatoon to complete a degree and then masters in mechanical engineering.
Air Barriers Were the Subject of Harold's Thesis
At the time, it was possible to calculate heat loss in houses through the walls, ceilings, windows and doors, but there was no available way of calculating air leakage. Harold used helium as a tracer gas and developed an instrument that measured the percentage of helium lost in the helium / air mixture. The assumption was that the helium would be lost at the same rate as air, however it does not behave that way, leading to artificial measurements.
Completing his masters and taking employment with the National Research Council, Harold continued to work on the problem and found that by changing the tracer gas to sulphur hexafluoride they were able to gain much more accurate readings, but it wasn't a practical system for doing a number of houses because of the time involvement, equipment and processes required.
By the late 1960s / early 1970s Harold's work had led to the development of the blower door, and inspired one company to start manufacturing them.
The Arab Embargo on Oil in the 1970s Prompted Research Into Solar Housing
The Saskatchewan government asked their research arm, the Saskatchewan Research Council, to build a solar house appropriate for Saskatchewan. Harold was part of the committee that was formed to work on the challenge. Given the lack of solar availability between November and April, hot water was going to need to be stored over from the summer time, meaning more energy would have to be put in than they would ever get out!
The Logical Solution was to Reduce Energy Consumption
The committee looked at ways to reduce energy consumption and one of the first considerations was the amount of insulation to use. Harold's suggestion was to avoid having a basement (which often led to problems), and use R30 insulation in the floor, R40 in the walls and R60 in the ceiling.
Harold and a colleague installed the air barriers themselves which resulted in the Saskatchewan Conservation House being the most airtight building in the world at that time (with a reading of 0.5 air changes per hour at 50 Pascals).
While the Committee Designed and Produced a Conserving House, the Government Still Wanted Solar!
They subsequently modified the design to incorporate a solar hot water system, including an 18ft high tank that was insulated to R100. The cost of materials and labour for the house had been $60,000. The materials for the solar system were $65,000! This was combined with a first year maintenance cost of $10,000 to provide the equivalent of $45 worth of heat with oil. It was no surprise when the house was sold that the new owner removed the solar system!
Such a Pioneering Project had Many Challenges and was a Steep Learning Curve
At the time there was nobody manufacturing triple glazed windows. Instead they decided to put shuttering on the windows, which didn't perform as they'd hoped, and with electronic operating switches on each individual one, they were never used! In at attempt to recover heat from grey water, the barrel system they developed had congealed waste soap from the baths and showers once the water had cooled down. And with such an airtight house, the airlock entry for the front and back doors proved to be ineffective.
The elements which did perform were the insulation, airtightness and ventilation system.
The Major Component of Heat Loss is Air Leakage
Harold stresses that people think they're doing the right thing by adding extra inches of insulation to their property, but without addressing airtightness they're not going to realise a substantial saving in their energy consumption.
As a rule, if building new houses, “build tight, ventilate right”. And if retrofitting, “make it tight and then ventilate right”.
A Documentary on Airtightness
Last year we made a documentary on the importance of airtightness. The aim was to explain the concepts in the simplest terms possible and hammer home the message.
If you haven't seen it yet, then we would encourage you to take a look.