The Green Gospel

2017/05/30 05:11:51 PM

 

Christian college among Manitoba leaders discoveing path to sustainability

May 19, 2017

OTTERBURNE — It was, suitably, a ball of fire in the night sky that was a turning point for a Christian school’s move towards environmentalism.

In late January 2014, the TransCanada Pipelines compressor station just west of Highway 59 blew, sending flames 200 feet into the air and melting part of Provincial Road 303, which leads to Providence University College.

"Students saw that and thought the world was ending," said business Prof. Bruce Duggan with a laugh, perhaps only partially joking.

About 4,000 Manitobans throughout southeast Manitoba were without heat for two weeks as crews scrambled to restore gas service.

Inside the college, however, students were kept toasty, despite temperatures dipping to -34 C with the wind chill. The school’s relatively new biomass generator, perking along on wood pellets from nearby Hutterite colonies, continued apace.

"When that blew up, we didn’t have natural gas for two weeks," said Duggan, who is leading a tour of the college’s alternative-fuel heating systems. "This (the biomass generator) is our belt and natural gas is our suspenders.

"We were glad we had a belt."

It’s May 12 and there are 49 of us on this tour, an annual event by Sustainable Building Manitoba that aims to highlight projects in Manitoba that point the way to a greener future. The four stops are Providence, a district geothermal system in Île-des-Chênes, the City of Winnipeg’s new East Yards complex and 482 Kylemore Ave., a study in passive-house construction.

The province may have low electricity rates that makes province-to-province comparisons difficult, said Dawn Fraser, chairwoman of Sustainable Building Manitoba, but it holds its own when it comes to building green.

"While the number of LEED projects is easily compared, the number of other sustainable building projects in Manitoba, such as PowerSmart, Passive House "shadow" and LEED "shadow" are difficult to compare because of different programming across Canada. However, it is safe to say the number of these projects is increasing each year at an exponential rate in Manitoba," she said.

"Leader or laggard? I’d definitely say leader."

LEED refers to a global program called Leadership in Energy and Environmental Design, and certification is administered in Canada by the Canadian Green Building Council.

At Providence College, four fuel sources provide heating to its campus: natural gas, electricity, biomass and geothermal. Duggan said it wasn’t tree-hugging environmentalism that drove the college towards greener heat. Rather, it was fiscal prudence.

With both geothermal and biomass, heating costs remain relatively fixed over a long period of time, and it was a desire to shield the college’s books from possible increases in gas and electricity rates that led the board of directors to explore alternatives, he said. He said that while the decline in recent natural gas pricing makes it a wash with biomass, the school is still happy about fixing long-term heating costs.

The first was a geothermal heating system for the Reimer Student Life Centre, using a horizontal loop system buried in the school’s courtyard. Then, when the school was told by building inspectors to move an old post-and-beam barn away from the dormitory, along came the idea to use it to house a biomass generator and heat most of the school’s spaces.

Biomass is old technology, having been used in Europe for a decade or more. It is, simply, a boiler, fuelled not by coal, gas or fuel oil, but by pellets made either from waste wood or waste grain products.

Wood pellets are delivered eight times a year, into a converted grain auger that automatically starts pushing the pellets into the two bins inside for storage. The system automatically feeds pellets into the combustion chamber on demand and ash is automatically deposited into a collector. A hot water-glycol mixture feeds into the school’s radiators through a series of natural gas boilers that serve only as backup. These boilers automatically sense when the water temperature is low and fire up.

"What do we do with the ash? Well, we found it was almost chemically identical to fertilizer, so we put it on our lawn," Duggan said.

Appropriately, it’s been a learning process for the school. The first lesson was finding out the new cafeteria building was oriented in the wrong direction, with most of its glass facing north, limiting heat gain in winter.

"Once we built it, we realized that, but it’s very expensive to turn the building around. That’s an argument for thorough, thoughtful design," Duggan said.

There was also the need to overcome trepidation about the biomass generator, which operates virtually without any attention from staff. Inspectors initially demanded the wood inside the old barn be clad in metal, for fire protection. They learned the biomass system is so efficient, it radiates little heat, pouring most of the energy into the water-glycol mixture.

Then, almost by divine intervention, the pipeline blew up.

"That laid to rest any fears about the biomass system," Duggan said.

Perhaps most importantly, Duggan said, the school’s leadership has learned environmentalism goes hand-in-hand with fiscal responsibility and the school’s mandate for "good stewardship of all that God has created.

"The fact it’s all Manitoba technology and Manitoba employees made a big difference to our board and our constituency," he said. The biomass unit’s water tank was from Quebec, but the combustion chamber, grain auger, grain bins, ash collector and piping were made in Manitoba.

Passive, not passé

Can you heat your home with a hair dryer?

If you buy 482 Kylemore Ave., you can.

The house, currently under construction, is built to nearly passive-house standards. That standard aims to produce the most well-insulated homes on the market, far beyond current standards for most new-home construction.

It starts with 18-inch thick walls, but also involves a radical rethink of typical construction methods, including steadfast attention to airtightness that eliminates the need for the typical plastic vapour barrier on outside walls.

A typical outside wall is built with studs, is sheathed on the outside, has insulation between the studs and plastic vapour barrier between the studs and the interior drywall. Thermal bridging, where the drywall, studs and exterior sheathing conduct heat to the outside of the home, remains a problem.

As well, in a conventional home, the rim joist — typically a 2-by-12 around the perimeter of the home — is placed flush with the outside of the basement walls and is nailed directly to the floor joists. While there is insulation between the joists, the rim joist remains a major thief of heat.

Perhaps the best way to visualize a passive house is to think of a conventional home wrapped in a continuous 18-inch blanket covering everything but windows and doors.

The way it works is this: what would normally be an outside wall is instead considered a service cavity, where electrical and plumbing can be run without regard for ensuring airtightness. This cavity is sheathed towards the outside — plywood is best but oriented strand board is acceptable — and taped at all seams. This sheathing forms the vapour barrier.

Vertical trusses are added to the outside wall to create a virtually unbroken 18-inch insulation cavity, filled with compressed cellulose insulation.

The exterior of this cavity is sheathed and finished — with stucco, clapboard, siding or brick or stone — like any house. For added effect, once any wiring and plumbing is run in the service cavity, it’s insulated, too.

The rim joist is shielded from the outside because it is to the inside the 18-inch cavity, which extends downward to where insulation of the basement or foundation walls takes over. At the roof, special roof trusses maintain this 18-inch insulation, eliminating another weak point in conventional construction, which is where the top plate of the wall prevents a continuous blanket of insulation.

The basement walls and basement floor (or slab and foundation walls, for a slab home) are also wrapped in 18 inches of insulating material.

Done properly, so little air escapes, a heat-recovery ventilator is required to bring in fresh air. To meet the passive-house standard, no more than 0.6 times the home’s volume must escape per hour.

Don Proven, general contractor at Sun Certified Builders Co-operative, which is building 482 Kylemore Ave., said the home was held back from completely meeting the passive-house standards by its narrow lot, about 25 feet, which prevented installing enough windows on the south of the home to capture heat.

Yet he said calculations show the home’s planned baseboard heaters — using the equivalent energy of a hair dryer — will be enough to heat the four-bedroom home in winter.

It’s more expensive to build to passive-house standards, but Wins Bridgman, whose BridgmanCollaborative Architects in 2016 designed Aspen Root, a passive-house prototype near Gimli, said for an average home in an average municipal development, it’s possible to pay for passive-house construction by reducing interior space by 10 to 15 per cent for the same footprint on the lot.

Aspen Root, using a small solar panel array, is expected to be less than zero in net energy usage. Bridgman and his client are monitoring energy use long-term to validate the prediction, but said already, the home is proving to be so efficient that in spring and fall, not only does the home not use any energy for heating, the owners have to open windows to maintain a comfortable temperature.

Bigger project, smaller investment

When does it make sense to cut costs by adding to a project?

In Ile des Chenes, the community found it’s when you’re trying to dump heat from an arena’s geothermal ice plant.

Roger Perron, who was the town’s economic development officer when a new community centre was built, said it was a perfect storm of coincidences that led to the town’s dive into alternative energy: a new community centre was on the way and at the same time, the neighbouring arena — built in 1974 — desperately needed renovations and a new ice plant.

The town investigated geothermal but discovered, even with plans for 60 vertical loops under the combined parking lot and heating and cooling a 30,000-square-foot community centre, making ice results in so much waste heat, they would either have to dump it into the air or drill for even more geothermal loops.

So the town expanded the plans to include the fire hall and emergency medical services garage, and accessed $1.2 million in provincial funding for a "district" geothermal system, meaning a system that ties multiple buildings together.

The result was four buildings, all with even, steady heat and cooling, heated bleacher seats in the arena and a lower overall cost for each building on the loop.

 

By:  Kelly Taylor

Winnipeg Free Press

kelly.taylor@freepress.mb.ca