Imber Akse House – Burlington’s LEED home

We have a major decision to make, and fast. From the beginning of the design process we had determined we would use radiant in-floor heating with a ground source heat pump if it were something we could afford. However we had preconceived notions about GSHP costs so we concluded a High Efficiency Natural Gas Boiler would have to do though it was a second best choice, a compromise due to price.

As we got into the process and learning curve we learned that the cost of the two technologies were closer together than we first understood. And when we considered that the GSHP could also provide heating for the pool on the same system, we realized that we were very close to making it a reality. So chopping we went, through the plan, to find room in the budget to go the rest of the way to afford the GSHP.

Recently, through investigating insulation and high performance building standards, we have come across research and recommendations from leading researchers that perhaps the NG Boiler may still be the better choice.

Here’s the debate. Let’s start by talking about money. It is our belief that for every dollar we have to earn, despite our efforts to reduce the industrial impact of our business, we inevitably mow down some trees, create some C02, and fuel our computers on Panda tears. So the most cost effective route needs to be involved in the sustainable equation. Simply, you can’t throw money at the sustainable problem without considering that the high footprint money spent outweighed the positive results unless, the positive results were infectious on others – another story.

So understanding that factor here’s the score card with other factors as we understand it:

GSHP Cons vs. NG Boiler

+ $ cost of money is higher for GSHP

+ the $ spent on GSHP could go to another sustainable feature with more immediate benefits

+ $ cost of electricity is currently higher than natural gas

+ environmental cost of electricity is greater than natural gas in Ontario (we burn coal!)

+ disturbance impact on your building site is greater for GSHP (drilling or excavating your yard)

+ GSHP requires a higher performance envelop to operate efficiently with lower output temperatures — requiring high insulation values, tighter sealing

+ not ideal for all situations, particularly extreme hot or cold average climate zones

GSHP Pros vs. NG Boiler

+ GSHP can easily be powered by solar, lessoning the environmental impact

+ GSHP uses only 1 fuel, NG Boiler 2 (NG and Electricity) – less dependency on utilities

+ GSHP has a lifetime supply of fuel from the get go, the ground, while the NGB is forever dependent on utilities

+ GSHP doesn’t introduce exhaust or venting issues into the home

+ GSHP uses less energy to operate within ideal ranges*

What’s the conclusion? If it weren’t possible to heat the pool with the GSHP and also install solar to run the GSHP we’d be immediately back to NG. Over the next few weeks we’ll conclude what’s involved in heating the pool and weigh in again. If the pool drops out of the equation, then NG it will be.

*For a comprehensive debate, see the attached document from John Straube, PHD, of Waterloo University and Building Science. bsd-gshp.pdf

Sustainability in general asks the consumer to consider a change in thinking. It sounds easy but in reality, the shift in thinking is a major shift for most people.

Sustainability asks – “pay now”, while the current culture says “pay later”. Think about it. Over the decades our culture and economy has slowly shifted to a platform of pay later. The concept of credit, mortgages, conspicuous consumerism, waste disposal or even our health system suggests you can do what you want today for free and pay later – no money down, no interest.

The problem with paying later is it’s always with interest — at tomorrow’s dollar too! It’s entirely unpredictable as well as exemplified by climate change.

So sustainability says “pay now” — at today’s dollar, predictably.

How does this apply? Well in particular if you apply the thinking to costs of sustainable products and services such as geothermal heating in the home, it makes it seem a lot more attractive.

Matt Irvine of NextEnergy says “we ask our clients to consider that when they purchase our Geothermal solutions they are buying a lifetime of heat and fuel”. Though the cost to do this compared to conventional heating seems high – 2 to 3 times higher — once purchased the cost to operate in todays dollar is practically free when compared to tomorrows dollar and diminished environmental impact.

Buying a conventional heating system asks you to pay for heating and fuel at tomorrows dollar plus increasing environmental impact. When added up, the conventional system costs much much more in the long term. When you think about it as a pure business decision, scenario 1 is responsible. Scenario 2 is irresponsible.

One of the passive technologies we’ve designed into the house and hope to utilize is the passive fresh air vent. Airtight efficient homes require fresh air to supply not only a forced air heating system but simply fresh air to breath. If allergies to outside air is not an issue as in our case, there is no need to filter outside air before it enters the home, you need only acclimate that air so that you don’t have to waste energy to heat or cool it. This is done by pulling air from the outside close to the ground, through air intake tubes that run underground, then through your foundation and tie into your ventilation system. Tah dah!

Instead of using electric fans to pull the air, this system uses the natural high and low pressure zones that occur in the home when warm air rises to the ceiling. The low pressure on the floor is a vacuum which pulls for any air it can get. Instead of that air being yanked from wall sockets or under wall baseboards (you’ve all seen the black streaks on white carpet at the base of walls), the path of least resistance is through the tube.

The pulling of the air through the underground thermal mass acclimates it to roughly ground temperature (12ºC+-) in summer or winter before bringing it into your home. This is essentially what a component of a good HVAC system does. We’re guessing that with the right thinking we can tie this into the heat exchanger so that we bring the air to interior temperature even further and reduce humidity in the summer. This system is passive and replaces electronic methods that might have pulled air from the roof or soffit height wall vents. This passive vent is sometimes called the Earth Tube. More info at TheNaturalHome.com

We’ve been looking for a turf solution that suits our criteria – aside from no lawn which might be a possibility except we have 2 children that love to roll around on a natural, flat and shaggy surface. Fine fescue turf grasses might be the answer if the info on this suppliers website is correct.

This cold climate fescue mixture from Prairie Nursery grows to only a short species height, is resistant to drought requiring next to no water and absolutely no fertilizers, enjoys sun or partial shade and only needs mowing twice yearly! If anyone has had experience with such a mixture or the like, please let us know.