Area resident hopes to harvest heat from soil

Who’d have thought a mix of alcohol and water would be enough to keep one warm and toasty this winter – without drinking it?

John McLean, who lives on Concession 11 in Wellington North, recently replaced his oil furnace with a geothermal heating system that will harvest the heat from the ground in the winter and provide air conditioning in the summer.

“It couldn’t be simpler,” he said.

Now-filled trenches contain plastic pipes that circulate an alcohol-water solution to his home – and replaces a forced air oil furnace.

There is quite a bit of pipe below the frost line – about 2,400 feet of it.

When asked how long it would take for the new system to be up and running from the time the trenches were filled, McLean anticipated only a few hours.

At the time of his tour for local politicians earlier this month, the remaining work included finishing the installation of the water heaters and pumping the oil out of the previous tank.

He had someone lined up to purchase that oil since his delivery company would not take the oil back, claiming it did not to have any liability insurance for waste oil.

“They  weren’t entirely help­ful,” McLean said.

He  explained that the lines are filled with a solution of 20% alcohol and water. It gets pumped out through the lines, under the ground, where the temperature is roughly 60F all year round. The solution  extracts heat from the ground and is pumped back into the house. The unit in the house has a condenser in it and puts it under pressure.

He said the heat gets ex­changed and there is a fan blowing over top of it – “and that’s your hot air. It’s like the back of your fridge, if you feel the back of your fridge.”

In addition, there are other lines that exchange heat with the domestic water system. That water is transferred to a pre-heat tank where is ends up at roughly 110F. Then there is a 60 gallon hot water tank with an element, but that water is already preheated and so not as much hydro is needed to top up the temperature.

He said the amount of tubing required depends on the size of building to be heated.

“It’s always warm,” he said, noting a circulating pump and a fan control the system. He said neighbours down the road had an open system that drew heat from two wells. This one, he said, is a closed horizontal system.

He explained there is the option of drilling a vertical well for the tubes, but people doing that would have to go about three hundred feet down.

He said if the tubes spring a  leak it should be able to be determined by a pressure drop at the pump panel. He added the liquid is environmentally friendly stuff.

“Basically what’s out there is gin and tonic,” he quipped.

It is not contaminating the domestic water because it is within a sealed system and the pump keeps it circulating.

Substantial savings

McLean said his oil bill in February was around $600 for one delivery, while the annual bill for the geothermal system is anticipated to be $1,100 to $1,200 for hydro – for heating, cooling, and hot water. It means he can save about $2,800 to $3,800 per year in such costs., or about 60% to 70% savings.

Unlike oil prices, McLean suggested electricity prices are more stable. He noted that between February and May he saw a 30 per cent increase in his oil costs – a cost he believed he could no longer afford if it increased further.

As for the company doing the work, he had them in a few years ago for an estimate.

Wellington North Mayor Mike Broomhead, who was on the tour, said he had heard that on similar systems for a 1,200 to 1,500 square foot house there was a seven-year pay back. But McLean suggested his personal pay back period will be between three-and-a-half and five years.

His is a four tonne system – roughly the equivalent of taking  four cars off the road for carbon emissions, McLean said.

One possible complication is the system is designed for the size of the home. If it is expanded later, the heating would need to be supplemented by another source, or more loops would have to be added to the heat exchange pipes. However, in his own situation, McLean said the system is designed slightly larger than what is needed.

The existing furnace was removed in addition to the connections to the duct work, which remains essentially un­changed.

Before putting the system in place, he had to have an energy audit done in order to apply for grant money. That included a door-blow test to determine where the house is leaking,

The combined federal and provincial grant amounted to $7,000 plus money back for the EnergyStar doors – based on the audits.

Once done, testers do a second audit to determine how much more energy efficient the house is. That is not based on a certain level of savings, but on the homeowner completing certain steps.

McLean suggested people doing this should keep the receipts to make sure the items are EnergyStar rated.

 The auditors are independent. The one he used was from Elora.

Broomhead said the systems have certainly come a long way since he first saw them. This is a far more efficient way of doing it, he said.

McLean said its a type of thing that can be done in town, except that the tubing would have be vertical instead of horizontal.

“That’s it … and the same equipment inside the house,” he said.

 

 

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