Aztext Press

Life Off-the-Grid

Cutting the Grass on your furnace…

Sorry about that. My previous blog was supposed to be about dealing with North America running out of natural gas and I ended up writing about our new electric bike. It was a glitch in the matrix. I was positively giddy over the new bike. I suppose that’s a good thing to show because when you start researching how dire our North American natural gas predicament is, it’s pretty easy to get negative. The reality though is that there are solutions; you just need to respond to them quickly.

While there a number routes you can go if you heat with natural gas, for most people the place to start is with a heat pump or geo-thermal system. Nearly 50% of the sun’s energy is absorbed by the earth. Moving this energy into the home offers an efficiency increase of between 2.8 and 6.7 times that of electric resistance heating. In other words, if you use a geothermal system to heat your home, you’ll still need electricity, but it’s 3 to 7 times more efficient than just using electricity in baseboard heaters. Systems are variously known as; ground-source heat pumps, heat pumps, water-to-water heat pumps, geo exchange, earth energy and geothermal systems.

If you dig down 4 or 5 feet, the earth stays a constant temperature. If you dig trenches and lay pipe in them and fill them back in, as you circulate a fluid through those pipes it takes the heat that is in the ground, even in the middle of a cold winter, and brings it into your house. The exchanger takes that heat and uses it to heat your home through your furnace ductwork or your radiant in floor heating system. But here’s the real beauty of the system, it works in reverse so that in the summer you bring cool water into the house and use it to air condition your home. It is more efficient than central air conditioning.

You don’t necessarily need a large rural property for a heat pump. The earlier systems used horizontal loops, which ran through the ground and they required a great deal of land. The newer systems can be installed vertically and just a few deep loops can be drilled in a smaller area. I spoke to a dealer at a homeshow recently who said he could put three loops in a driveway and pave over them and you’d never know they were there. You’ll be parking your car on your furnace. The photos at the top and bottom of this blog entry are of an installation in a small suburban front yard. It looks a little messy while it’s happening but it cleans up nicely.

This all sounds great and it is! A geothermal system may cost about $25,000, which sounds pretty expensive. If you talk to a furnace salesperson right now they’ll tell you that you should be installing a high efficiency furnace instead. Let’s say this costs $10,000, which sounds like a much better deal. But remember, most people will also install central air-conditioning, which might be another $3,000 or $4,000. In Canada right now if you have an Eco-Energy Audit done, you’ll get up to $7,000 back for the purchase of a geothermal heating unit. So suddenly that $25,000 purchase price is knocked down to $18,000, pretty close to the price of a natural gas furnace and central air conditioning. The difference is that with the purchase of a natural gas furnace you sign on for a lifetime of purchasing a rapidly diminishing fossil fuel, which sequesters carbon in the ground if you leave it alone, but releases CO2 into the atmosphere when you burn it. That central air conditioner will require more electricity to run than the geothermal system in the summer. The fact that our government will kick back $7,000 to help you do this tells me they are getting a pretty good handle on the fact that days of cheap and plentiful natural gas in North America are over. Kenneth Deffeyes reports in “Beyond Oil: The view from Hubbert’s Peak”, “Between 1980 and 2002 the best of the natural gas targets were drilled. We’re now being served the leftovers.”

With your geothermal system you will have to purchase electricity but in much smaller amounts than if you heated with electric heat and cooled with central air. Seems sort of a no brainer to me. I can’t tell you how many people have come up to me after workshops and said, “Oh, I just bought a new natural gas furnace. That’s what the furnace sales person said I should do.” Of course they did. They don’t sell heat pumps so would rather you not buy one. The reality is that if they want to stay in business they’re going to have to learn how to install heat pumps very quickly because as the price of natural gas skyrockets in the next few years, people will be bailing on it as a heating fuel.

I know a number of people with heat pumps and they love them. They have been around since the 1970s and the early adapters worked out the “bugs”. Back then you often heard negative comments about them. More recently I’ve met a number of people who have geothermal systems and they’ve told me that they work really well and they really like them. My main concern today is that we’re going to hit a wall very soon with natural gas and that the demand for heat pumps is going to outstrip supply. There won’t be the product and there won’t be enough skilled staff to install them. If you are evaluating your home heating and cooling system now you should be investigating a geothermal system very seriously, now. Cut the dealers some slack. They have been fighting an uphill battle for many years and it’s only recently that people have been demanding the systems.

Another option for heating without natural gas is biomass with a woodstove or pellet stove. But that’s for the next blog.

Inserting the pipe that will extract the heat from the ground

Once the grass grows back, the kids can play on the furnace. No CO2 produced. No fossil fuel bills!



  1. Great site this and I am really pleased to see you have what I am actually looking for here and this this post is exactly what I am interested in. I shall be pleased to become a regular visitor 🙂

  2. Brian

    Is it possible to produce enough electricity using wind and solar to run the geothermal ?

    • aztextpress

      The short answer is probably not. The pumps used to run a geothermal system require a fair amount of electricity and you will be running your geothermal system right at the time of year when there is the least amount of sunlight for your solar panels (at least here in Eastern Ontario). Unless you have a very large bank account and can afford to purchase many, many solar panels, geothermal is a not a good choice for someone who is “off-the-grid”.

  3. excellent site this great to see you have what I am actually looking for here and this this post is exactly what I am interested in. I shall be pleased to become a regular visitor 🙂

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