Geothermal heat and insulation

On Tuesday morning, I participated in a meeting at Cosburn Middle School organized by Gord Crann, the candidate for school trustee you may remember I endorsed.  Gord had come to realize that the lawn at the school needed to be resodded, and thought this would be an excellent opportunity to install the loops for a geothermal heating project.  Gord is promoting this project and brought in Ben Chin, the former (and presumably future) Liberal candidate in the provincial byelection to meet with school officials.

While I’m supportive of any project that reduces energy demand, my involvement in the project so far has been to redirect the enthusiasm to the best and most cost-effective solutions.  This process demonstrates the challenge of reducing energy use in buildings, particularly in a world where the price signals do nothing to encourage retrofits.

Cosburn Middle School and its associated high school are poorly insulated buildings with high energy costs.  However, in a city where almost all schools have no insulation at all, and some schools are literally crumbling, they do not stand out asking for attention.  The reason they attracted Gord’s notice was that they require resodding.  And in Gord’s mind, resodding was an opportunity for geothermal heating.

Geothermal heat pumps exchange the coldness in buildings for the heat in the ground during the winter, and reverse the process in the summer.  In the winter, they do not contribute much to reducing global warming, because although they draw 3-4 times the energy in heat from the ground as they take in to operate, what they take in is electricity, currently produced in Ontario in coal plants that only run at 1/3 efficiency.  In the summer, when they replace electric air conditioners instead of natural gas furnaces, they offer a benefit, but only if they replace air conditioners.  If they create additional demand for electricity that wasn’t used before, they don’t help at all.

Geothermal heating is interesting to most Canadians, but dollar for dollar, you can’t match good old boring insulation for reducing the energy demands of a building as the most important first step.  Installing an enormous geothermal heat pump for a leaky old building is an absurd approach.

Last year, I was promoting geothermal heating for new construction.  It can produce significant energy savings, particularly during the summer cooling season if it replaces a system that includes air conditioning.  However, as I’ve come to question the way we’re building new buildings, I’ve become convinced that geothermal heating is only a solution to a particular set of problems which we shouldn’t be creating in the first place.

We should be dramatically reducing our air conditioning load.  When we moved from a new built townhouse downtown to our leaky old house in Riverdale, I expected our energy bills to skyrocket.  Ironically, while our heating bills have soared, we are comfortable without air conditioning through the summer except for a small number of days.  Older houses have deep eaves, we have a large shade tree here and we don’t have the enormous exposed south-facing wall that our first house has.

Which demonstrates that design has an enormous impact on energy demand.  If we added proper insulation to a sensibly built structure, the impact would be even greater.  The Healthy House on Sparkhall has no furnace or boiler, and has lower heating costs than most comparably sized houses even though it relies on electric resistance heaters.  The reason is insulation.

There are building standards in existence today that dictate the complete elimination of heating systems through design and insulation.  Structures built to these standards eliminate the fan noise and humidity/dryness control problems of conventionally heated buildings, and are more pleasant to live in as a result.

But it’s the air conditioning load that’s truly absurd.  And that’s the primary advantage of geothermal systems.  My Brazillian relatives endure scorching 40+ temperatures for 8 months of the year without air conditioning.  Do we really need it in Canada?  We seem to live in defiance of the natural elements around us, rather than working with them.  Could it be that what we really need is not a piece of technological wizardry but an attitude shift, some careful thinking, and some good old-fashioned insulation?

One response to “Geothermal heat and insulation”

  1. Richard writes:

    A resodding project that turns into a geothermal heat pump project? The reason geothermal is not as popular as everyone would like it to be is the cost of installation versus traditional heating and cooling methods that can be viewed as energy hogs. For schools it is a budget factor where they rob peter to pay paul. Low initial installation cost for traditional equipment with higher energy bills versus the high installation costs of geothermal and low energy bills. Unfortunately most governments choose low installation cost and higher energy bills over the other choice which does save energy in the long run.

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