December 20, 2010 in News, Green Energy

Heat from below helps lower heating his home

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(Full-size photo)

In part, John Adrain bought his house in northwest Spokane for the great views of forests and peaks.

But those views came at a premium. In the winter, the windows in his two-level home accounted for 80 percent of heat loss. The 3,100-square-foot house, built in the 1990s, primarily relied on two oil furnaces for heat.

Some cold months Adrain said he paid more than $1,000 per month on heating.

An inventor and entrepreneur, Adrain did some research and decided to install an underground geothermal heating and cooling system.

“It’s great to go out and invest in solar heating. But, for me, the first step was to reduce the amount of energy I’m using,” he said.

After three months of work, Adrain recently watched as workers hauled the oil furnaces to the dump. His home now hums along on a new geothermal system that also provides him a 30 percent tax credit on the cost of installation, including the hefty price for drilling the eight wells.

He expects to save between $7,000 and $10,000 a year for heating and cooling.

As oil and gas prices fluctuate upward, more homeowners are looking at the option of geothermal energy to heat and cool their houses. But even with a 30 percent federal tax credit, demand hasn’t increased in the past year.

Northwest Geothermal, the Hayden, Idaho, contractor hired by Adrain, does about one geothermal installation a month, says owner Jason Bartel.

Spokane-based Holliday Heating & Air Conditioning, a company that’s been installing geothermal systems for about 15 years, also does about one system per month.

The main effect of the 30 percent federal tax credit has been an increase in the number of area firms offering to install geothermal systems, said John Munro, main sales representative for Holliday Heating.

“Even with the tax credit, people are not looking at geothermal unless they were already looking at geothermal before,” Munro said.

“It did push a few of those people over the top to buy a system,” he said. And many of those are people with large houses dealing with steep energy costs, Munro said.

That would describe Adrain, who said he hopes to recoup the cost of installation in four or five years. He chose to not disclose the full cost of what he paid to install the system.

“All I know,” said Adrain, “is that the price of oil and electricity will increase, and the cost of this (geothermal) system should not increase much at all.”

Avista Utilities does not provide incentives for residents installing such systems. Company spokeswoman Debbie Simock said the payback takes too long for the amount of energy saved.

Adrain’s geothermal system takes cooled 37-degree water and pumps it underground through ¾-inch plastic pipes to a depth of 200 feet. There the cool water absorbs ground heat and goes back up the loop where it re-enters the house at roughly 50 degrees.

Once back inside the house, two heat-exchangers in the basement removed the heat from the water and blow it across the home using standard air ducts.

In the summer, the process is reversed, with the added savings of having the house’s hot water tanks heated in part through the transfer of heat as the house is cooled.

The main advantage is that geothermal systems can count on ground temperatures remaining steady, any time of year, Bartel added.

Adrain’s system uses eight wells, all at 200 feet, to provide enough heat transfer to keep the house comfortable.

A number of regional companies or businesses have installed systems pulling water from the aquifer for geothermal cooling and heating. In those cases the systems first needed state approval to remove water from underground and put it back in, with no contamination.

In a closed-loop geothermal system like Adrain’s, no water is removed from or added to the ground. The system uses a fixed volume of water in the pipes and recirculates it.

Washington regulates the construction of the wells drilled for closed-loop geothermal, said Ecology Department spokesman Bill Lum. Adrain needed to use a licensed well driller, he added.

The polymer lines used for the wells are durable and are guaranteed for 60 years, Munro said.

“They’re also butt-welded so they use the same technology that is used for underground gas lines,” he added.

Munro said the big change in recent years is the improved technology that keeps the systems working efficiently. The key factors are consistent water flow in the pipes that send cool water below ground and send it up to the heat exchanger in the house.

“When people don’t properly design the system and know the right amount of water line to use, it can cause problems” such as inefficient heat transfer and loss of energy, he said.

“Anyone can do it, but doing it right is the big question people need to think about,” he said.

Two comments on this story so far. Add yours!

• 

  Walter on December 20 at 6:26 p.m.

  John Adrian makes sense…why put in way too much solar or other renewable energy product when the first step should be to reduce? No where can we reduce more than geothermal heating. I read mcGraw hill’s book, “Geothermal HVAC” last week and the author had much the same idea as John, only 20 years ago. The book was great, and I’m looking forward to getting my system installed sometime after the first. I’m really glad i read the book…there are some snake oil slaes guys form some heating companies. They’d tell me they knew all about geothermal, then they would either try to sell me a gas furnace, or they’d pretend to know what they were doing, and I’d see right through in seconds, because i knew of what i was speaking. Wow! It’s the best money I’ve ever spent on energy efficieny. I just did an internet search for “GEOTHERMAL BOOK” …no problem!

• 

  mdriftmeyer on December 21 at 3:12 a.m.

  As a Mechanical Engineer, if you’re spending $7000 - $10,000 a year in oil based heating, then your thermal system is not closed and you have bigger issues than just dumping $40,000 and tearing up your land for a Geothermal system, which at those prices will never replace Gas, for urban/city consumers.

  The cost for two 95% efficient variable rate gas furnaces, with proper input/output lines to garner that 95% efficiency, including labor will run you about $6k, if you’re using the same size units for each zone.

  You wouldn’t do that with a 3100 sq ft, area to manage. With two equally managed zones you can buy less expensive 95% variable rate furnaces as your heat zone is < 2000 sq ft per unit.

  More importantly, you’ll want to spend the time to check how much your home is presently leaking heat and how resistive it is to external temperature variance so you can optimize your home.

  R30 walls and sub-flooring when in a home w/o a built out basement is a must. Having a R60 in the attic flooring will tie off that heat dissipation. You’ll have to check the joints in the home where insulating them is much harder to guarantee. All forms of heat follow the path of least resistance, so you’ll have to make sure the seams are protected. Then make sure you have cross-ventilation in the attic to keep the floor to rafter temperature regulated in the hot summers.

  Most old oil based furnaces suffer from low efficiency, just like their counterparts, gas furnaces. If you’re replacing a furnace that is as old or older than yourself you most likely won’t have anything greater than 50% in efficiency.

  Converting to a 95% variable stage gas furnace [let alone two of them for specific zones] alone should drop his bill massively. Its obvious benefit from oil goes without mentioning.

  Solar has nothing to do with it when you’re not using an electric based heating solution.

  With photovoltaic cells > 40% efficiency you can match, on average, your power draw from the local PUD for around $5k - $8k, depending upon your consumption.

  If you amortize that over the next 10 years I doubt you’ll be complaining about the savings.

  However, a poorly insulated system [your home] is the first problem that must be addressed. Otherwise, you’ve spent $40,000 on Geothermal as an overpriced solution while the system continues to bleed heat loss [dissipation] at the same rate it was regardless of your heat input solution.

  Heat pumps are another excellent solution if a standard gas furnace is not your cup of tea.

  Geothermal seems like a rather obvious solution for Rural homes where the cost of running gas lines last mile solution is on the back of the home owner.

  Solar for the Rural [Farm/Ranch] is another obvious solution as the cost to run a power line from your local PUD is going to cost you greater than $10k just to get to the home.

  When Photovoltaics reach 60% efficiency you’ll see PUDs lobbying to stop their mass deployment by forcing people to buy a control unit from them as a means to recoup their loss of revenues. Of course, at that point with Boeing being the current leader of such research in the US, along-side NASA and other corporations like FirstSolar the PUDs won’t have much leverage to block them.

  In the end, highly efficient solar [> 60%] with quality caption solutions [the PUD will most like want to be the solutions provider of these systems] will become a common feature of homes, especially as the surface area of the capture cells brings it down into a managed casing that covers only a fraction of today’s surface solutions.

  If Geothermal can be done for < $10K to heat homes up to 4,000 sq.ft it’ll become another common solution for home owners. Until then, it’ll be more for special needs.