Toronto Renovation Stories & Expert Advice

A geothermal furnace in the city?

Whether you call it geo-thermal, ground-source heat pump or an earth-energy system, it's a heating and cooling system that uses very little electricity and no gas, oil or propane. Whatever you call it, the system starts with pipes that are laid in the ground and a liquid circulates through them drawing heat from the ground and taking it into the house. In the past geothermal has been common in rural areas where a gas connection was non-existent or outrageously expense. Also, pipes are laid horizontally on large expanses of lawn or field something that isn't very common in the city.

Last year when I was at the Metro Home show (and I'm back there again now actually) I spoke with a man who installs these systems (Unfortunately I don't remember his name or company). I asked him how much lawn space he needed as I'd read on the internet that you needed a 75 by 75 foot expanse to install one. He said not at all. Now they can be installed in the driveway. Vertically.
Well, that makes sense, I thought. "But what happens if there's a leak in one of the tubes?" I asked.
"The pipes we use are guaranteed for 50 years."
"So how much is this system?" I asked.
"Depending on the size of your house and its HVAC system, how airtight it is...(etc.) about $9000 for the pipes and $6000 for the unit. It's a better deal if you have to replace both your air conditioner an your furnace."
"Yikes," I said, and felt my mouth go dry.
The man shrugged, I guess he'd seen this kind of reaction before. "Think about it though," he continued, "that's your cost forever. You never have to worry about soaring gas or electricity prices. It's a fixed cost. If you spread that out over ten years it's $1500 a year. I'll bet you pay more than that in gas right now." It was a good argument, since in fact I do pay more than that for gas. But he hadn't finished with the sales pitch. "If you're replacing your furnace and air conditioner anyway you're going to be shelling out somewhere around $6000 so you can look at the installation of the pipes as your only additional cost. It pays for itself before you know it." I thanked him for the information and went on to the next booth and my adventure in geo-thermal heat pumps came to an end.... Or did it?

Now, I'm not one to keep things to myself, and I'm a pretty enthusiastic environmentalist (sometimes too much of the 'armchair' variety than actual activist, but I try), so I started chatting to people about this geothermal system. Of course no one I knew had one...or so I thought. It turned out someone I know does have one! So I said, "Lisa, can I come over to your house and take pictures of your furnace?" (how exciting, a furnace!) She was kind enough to say yes so that's how the pictures you see below ended up here.

When Lisa and Herman first talked about installing a geo-thermal furnace in their soon-to-be renovated house there was a lot of skepticism on the part of their friends. After all, how effective could a furnace be that used heat from the ground, particularly in a cold Canadian winter (this winter doesn't count). "Our friends told us that if our house was ever too cold, we could stay at their place for the night," says Lisa. Their friends were skeptical that heat from the ground could keep a home warm. However, seven years later, Lisa and Herman are more comfortable than they ever were with a conventional system. "The system heats and cools evenly, and there are no jumps in temperature. It's the most comfortable house we've ever lived in," she says.

Lisa and Herman have installed what might be considered the "Lexus Hybrid" of geo-thermal systems. To make the system even more efficient, their HVAC designer added a heat recovery ventilator (HRV) which transfers the heat from the used, outgoing air to the incoming fresh air. The HRV warms the fresh air before it even gets to the furnace (compressor system) making the furnace's job that much easier. They also hooked up their hot water tank to the system which cuts down considerably on their hot water costs.

The geothermal system also replaces a central air conditioner. In the summer the system reverses itself and warm air is extracted from the house and carried by the pipes back to the ground, it's the same principle as a refrigerator. In fact, their system is so automatic that even in our currently unpredictable spring temperatures where it can be 25 degrees Celsius one day and 4 degrees the next, the system will adjust to cool and heat.

Hindsight is 20/20: As with any new application, there were certain drawbacks with the system's installation. The system's size was much bigger than Lisa and Herman anticipated, especially the venting system, so they ended up forfeiting space in the workshop in order to install the furnace. "If we were to do it again, we'd have definitely dug out the basement to provide the extra room for all the vents," says Lisa.

Another glitch they ran into was finding qualified people to maintain it. Initially, there were problems maintaining the pressure in the pipes that carried the liquid anti-freeze to the compressor unit. The installation of the pipes was fine, but the connection to the compressor unit wasn't done properly. Air became trapped in the system and it wasn't working as efficiently as it could have been and the pumps circulating the antifreeze liquid through the pipes burned out. "When we put the furnace in seven years ago, there were very few people who were familiar with geo-thermal units in the city. It took us awhile to find the right company, but now that we have, we're really happy. Chris comes to maintain it about once a year now and the pressure in the pipes is fine," says Lisa.

The technology is only getting better with age, and now, as people are beginning to retrofit homes, the manufacturers are making specific models adaptable to many different situations; units have been developed that can be installed outside like a central air conditioner, added to a current furnace to heat an addition, hooked up to a boiler, etc....

There is more detailed information available on how a geo-thermal system works if you check out the websites I've linked below. The Climate Master site is the manufacturer of the unit that Lisa and Herman have installed (in fact they installed the "Ultra Classic Series" by Climate Master. The distributor in Canada is Next Energy Solutions).
Climatemaster.com
CanRen.gc.ca

Reviews:

Vision Energy:

Chris Cody maintains our furnace and he does an excellent job! We had a lot of difficulty finding someone who understood the finer points of a geo-thermal furnace, but now that we've found Chris it's been a cinch to maintain. Chris comes and makes sure it's working well about once a year. We're really pleased with his service and we've finally found someone who knows what they're doing with ground source heat pumps. Thanks for the great work Chris!

Groundheat Systems:

Gino's company took care of designing our geothermal system and installing it. Overall we were happy with the work, the system design in particular. An HVAC specialist came into our house and calculated the system size, the size of the vents needed, the air leakage, and how to best optimize the installed system. The HVAC specialist added a Heat Recovery Ventilator, air purifier and humidifier to the system. We also hooked up our hot water tank to it, and that also has helped reduce our energy costs. The installation process wasn't quite as smooth. Gino sub-contracted the job to a company that's now out of business. They didn't hook up the system properly and we had pressure problems for years. He did however, recommend Vision Energy for maintenance, and since they've taken over, we haven't had any more problems.

Labels: alternative energy, geothermal, heating and cooling

Posted by Cathy
3 comments | Permanent Link