By CCHRC Staff

Q: Recently I read the News-Miner story about the heat pump being installed at Weller Elementary School. Are there different ways to install this type of system and is this something I can do myself?

Ground source heat pumps operate in a way similar to how a refrigerator transfers heat out of an insulated box to the surrounding air of your kitchen. In this case, the heat pump absorbs heat from the ground and transfers it to a home. The heat exchange mechanism between the ground and the heat pump is typically a series of liquid-filled tubes.

There are different methods to get the heat out of the ground each of which require different installation needs.

One system is the shallow horizontal trench, which is being used at Weller Elementary.

In this configuration, the tubes are made into overlapping loops and placed approximately 10 feet in the ground. For people who live in areas of shallow ground water, it is beneficial to get the loop below the ground water table. This requires a large area, so this type of system is probably not feasible in a downtown lot, but would work well on a southsloping hillside with a lot of land available.

Another option to consider is drilling multiple wells.

These would be similar to drilling a drinking water well for a home, except that only the heat in the water is being extracted, not the groundwater itself. It is likely that more than one well would be needed to heat a house.

The third option is to sink the ground loops deep into a body of water such as a pond or lake, provided that the water body is sufficiently large to accommodate the heat demand. Contact the Alaska Department of Environmental Conservation before beginning this type of project.

All of these options are for a “closed-loop” system, where freeze-protected fluid is circulated in a closed system of piping. There are also “open-loop” systems that draw ground water directly and then inject the water back into the ground.

In most cases these are not appropriate for use in Interior Alaska.

In terms of a do-it-yourself project (and Alaskans are pretty handy) a heat pump involves digging a deep well or large trench, which will probably require hiring a driller or excavator. The equipment that makes up a heat pump is technical. Hiring someone who has been certified by the manufacturer or by the International Ground Source Heat Pump Association to install these systems is recommended.

Contact local heat pump distributors to get more information on installation.

Alaska HomeWise articles promote home awareness for the Cold Climate Housing Research Center (CCHRC). If you have a question, e-mail us at akhomewise@cchrc.org.You can also call the CCHRC at (907) 457-3454.

Large rolls of black tubing sat like super-sized balls of yarn next to the playground outside Weller Elementary School Wednesday. The sun shined brightly on the south-facing hillside, where a bulldozer carved out a 12-foot hole.

The balls, which are actually polyethylene ground loops, were then rolled out and buried in the ditch, where they will harvest heat from underground to use in the school during the winter. In the summer, six solar thermal panels soon to be mounted on the school will replenish heat to the earth through the same tubes. The system will not only reap savings on heat for the school district but also will test a technology that is young in Fairbanks.

“I would like to see a system that would work well in the Interior and that the public can utilize and save dollars,” said Larry Morris, projects manager for the Fairbanks North Star Borough School District.

The project is an experiment to see how well the systems work in tandem and to collect data on ground source heat pumps, which are common in the Lower 48 but rare in Fairbanks.

“What we’re trying to do here is pair that system with a solar system that will recharge the heat you take out of the ground. In warmer climates, the sun can recharge how much you take out,” said Aaron Sirois, an engineer for PDC Engineering. “We were trying to come up with a solution that’s kind of adapted to Fairbanks.”

For years, the Aleutian village of Akutan has seen the energy potential in its hot springs and fumaroles. Now, it looks like that potential might be realized.

In July, work began on two exploratory wells. The first one was drilled on July 16, and it’s producing hot water at more than 360 degrees. The exploration team is drilling a second well, and they’re optimistic that the water will be similarly warm.

If it is, the exploration phase will end and the city of Akutan will start working on a power plant that would harness the steam from the ground and use it to power electrical turbines. Ray Mann is Akutan’s project manager, and he’s been working closely on the exploration project. He explains that Akutan – with its hot water at shallow depths – is particularly well suited for a renewable energy project like this.

Right now, Akutan uses diesel as its main energy source.  Mann says because the cost of energy is already high and expected to get higher in the future, a geothermal plant could help save Akutan’s residents a good deal of money.

Continue reading: Akutan geothermal test exceeding expectation

The Naknek Electric Association is drilling a well near King Salmon to test the potential for geothermal energy.

Association General Manager Donna Vukich told KTUU-TV the search for renewable energy from underground heat has been a 10-year, $20 million project. If successful it could serve villages across Bristol Bay. The project requires a second test well to be drilled in September.

Naknek Electric currently relies on diesel to generate electricity.

By CCHRC Staff

Q: I am going to dig up my foundation this summer so I can put on outside foam insulation.

How far down should I dig? How long will the ground be frozen?

If the foundation has not been waterproofed or the product that is installed needs some touching up, then clean the area thoroughly. In the case of cement block or cast-in-place concrete, cleaning will probably involve hosing off the foundation, letting it dry, waterproofing it, then adding the insulation. For waterproofing, apply a peel-and-stick membrane or a waterproof foundation coating. Be sure to follow the application instructions carefully. These membranes work well for both new construction and retrofits, but the concrete must be clean first. If your foundation already has good waterproofing, then dig away the dirt, brush off the foundation and place the foam tight against the wall. In terms of how far down you should dig, remember that heat always goes to cold. Where you have a temperature difference inside to outside, you are going to have heat loss. The bigger the temperature difference, the more aggressively the heat will try to escape. The frostline in Fairbanks goes down roughly 4 feet on average.

Some winters, that frostline goes much deeper. Below the frostline, there is an average soil temperature of 32 to 40 degrees. A good practice is to apply rigid foam insulation that is approved for direct burial, all the way down to the footings.

Fairbanks building code requires three inches of thickness for foam below grade (below the soil).

Good resources for finding out when the ground has thawed would be the local excavation and septic companies. They work in locations throughout the area and may be able to help you predict the thawing time for your location. June is usually a good month in which to begin excavation, though if you are on the north side of a hill, in a heavily shaded area, or have wet soils, your ground may behave differently.

Q: Where can I go if I want more information on ground source heat pumps?

There is information on our website (www.cchrc.org) including heat pump resellers in Fairbanks. Also the Department of Energy has a website dedicated to energy efficiency and renewable energy (www.energysavers.

gov.) The site has general information about how heat pumps work and the considerations in installing a system. The Permafrost Technology Foundation website (www.permafrost.org) has several technical reports on the use of ground source heat pumps in permafrostladen soils. As ground source heat pumps grow in popularity, we are seeing more being built in the Fairbanks area. CCHRC is beginning research projects that will look at the effectiveness of ground source heat pumps in our region and should have some preliminary information on our website by next spring.

Alaska HomeWise articles promote home awareness for the Cold Climate Housing Research Center (CCHRC). If you have a question, e-mail us at akhomewise@cchrc.org.You can also call the CCHRC at (907) 457-3454.

By CCHRC Staff

The “Ask a Builder” series is dedicated to answering some of the many questions Fairbanks residents have about building, energy, and the many other parts of home life.

Q: What is a heat pump and can it work in Fairbanks?

A heat pump is a mechanical system that uses a series of liquidfilled pipes or tubes run underground to heat (or cool) a building. The liquid captures the ground heat and uses it to heat your home. You might think our Fairbanks ground would be too cold to support such a system, but even at lower temperatures a heat pump can still function appropriately. In Alaska, this tubing has antifreeze added.

In Fairbanks, these tubes need to be buried below the frostline (about 10 to 12 feet down) where the temperatures are fairly stable across the seasons. Heat pumps use more electricity than the typical house, but the increased costs are offset by the savings in fuel. There is some concern that, depending on your site, the heat pump will take enough heat from the ground to cause freezing, however more research needs to be done on this question. Locally, we’ll probably see more of these systems being installed in the next few years, but for now, it is an emerging technology for our area.

Q: My boiler needs to be cleaned. Is that something I can do myself, or should I call a professional?

You can do it yourself but it is a messy and sometimes difficult job. Older boilers may require removing side shields, top pieces, gaskets or other parts that can be damaged and cause leakage.

Most newer boilers have hinges and open from the front, making them much easier to clean. These boilers make it simple to get a brush onto the heat exchange surfaces and leave few places to gather soot. In the long run, it is probably best to have a professional do the cleaning.

Q: If I want to build a higher tech home and add some solar panels or wind power, how does orientation play into that?

Fairbanks is a tough place for wind power because it is generally a calm region of the state. The orientation of your home will not be a hindrance to adding any type of wind system as long as you have the wind resource. High areas in the hills around Fairbanks have the best potential for this kind of renewable energy system. Fairbanks is certainly a good place for solar much of the year. Solar systems should be oriented to the south in order to catch as much light as possible.

If you are building a new home, orienting it as much as possible toward the south will be advantageous for any kind of solar energy collection, whether passive or panels.

If you want to add solar panels on to your house, place them on your roof or outside walls at the height they will collect the most light.

Before making any decisions it is best to contact a solar installation company that can do an assessment of your property. These companies can do an analysis that will tell you where panels will receive the most sun exposure year round.

Alaska HomeWise articles promote home awareness for the Cold Climate Housing Research Center (CCHRC). If you have a question, e-mail us at mailto:akhomewise@cchrc.org. You can also call the CCHRC at (907) 457-3454.

“Was I to believe him in earnest in his intention to penetrate to the centre of this massive globe? Had I been listening to the mad speculations of a lunatic, or to the scientific conclusions of a lofty genius?”

These lines are from the campy adventure novel, “Journey to the Center of the Earth” by Jules Verne. Science is cool, but science fiction is cooler. Writers apprehend the future in their fantasies, often articulating what scientists later invent. Though writing in the 19th Century, Verne appears to have anticipated modern-day air conditioning, submarines, and television.

In Verne’s inner-earth journey, readers discover the massive heat and steam buried deep beneath the ground. This energy can be tapped for a variety of uses. In the case of the local Chena Hot Springs Resort, for example, hot water from the ground is used to heat rooms, keep greenhouses warm during winter, and (using turbines) even generate electricity.

Geothermal energy is renewable, non-polluting, and reliable. Alaska might be frigid much of the year, but is brimming with natural energy below. The potential downside to geothermal energy is the difficulty of tapping that energy, which can require a significant investment. Fortunately, geothermal power comes in several forms and can be affordable even for residential use.

In Fairbanks, heat pumps can be used to capture heat from the ground or even bodies of water. Heat pumps are powered by electricity to move heat from these sources to the inside of a home or building. They work similarly to the way your refrigerator does – a compressor pump moves heat from the inside of the refrigerator to the outside through the use of special heat transfer fluid, which collects and releases energy by changing phase from liquid to gas and back to liquid.

Heat pumps are very efficient because they do not have to generate heat; they only have to move heat. Furthermore, heat pumps can move more energy than they require to work, which results in very low operating costs. Roughly speaking, for every unit of energy a heat pump uses, it can deliver two to three comparable units of useable heat.

Chena Hot Springs Resort’s naturally occurring hot water is estimated to circulate some 3,000 feet to 5,000 feet below the ground and reaches the surface at about 165 degrees Fahrenheit. However, in the case of residential heat pumps, the differences between above and below ground temperatures do not have to be so great for a heat exchange to occur. Neither do residential systems have to reach such depths.

The two major types of heat pumps are vertical and horizontal systems. Horizontal systems require the installation of several hundred feet of looped piping 10 feet to 15 feet below the surface. The length of pipe is designed to maximize heat exchange over a large surface area. The relatively shallow ground used by horizontal systems may fluctuate in temperature seasonally more than ground farther below, but is generally less expensive than vertical systems because typically it is easier to install.

In a vertical system, pipes are placed in a narrow loop 150 feet to 200 feet beneath the surface, where the ground temperature remains constant year-round. Vertical systems, which are more compact than horizontal systems, are used where land is limited or obstructions exist, or where ground temperatures nearer to the surface are too cool. Because of the expense of boring holes, vertical systems tend to be more expensive to install than horizontal systems.

Heat pumps can also use bodies of water to work. Water-source systems use pipes that are laid on the bottom of a lake or pond where the water remains unfrozen during the winter. Other water-based systems use wells, if it is permitted by local code.

Something to keep in mind with heat pumps is the possibility that over time more heat could be pumped out of the ground or a body of water than is replaced, causing the heating system to fail. CCHRC is researching the use of heat pumps in Alaska, including the possibility of “recharging” ground-source systems in the summer using solar technology and other ways of storing heat seasonally.

Adam Wasch promotes energy awareness for the Cooperative Extension Service (CES) and the Cold Climate Housing Research Center (CCHRC).
For questions or comments please contact CCHRC at (907) 457-3454

The stimulus bill has finally been passed and signed into law—and now it’s time to help put the thing into action. Which shouldn’t be tough to do: tucked into the thousands of pages of confounding language, there are tons of fantastic new tax credits you can get simply for buying great green stuff. Here’s what our government’s blowout sale’s got in the catalog.

Click here to see the list.

President Barack Obama signed the American Recovery and Reinvestment Act of 2009 on February 17, and the tax section of the act provides greater tax credits for clean energy projects at homes and businesses and for the manufacturers of clean energy technologies. For homeowners, the act increases a 10% tax credit for energy efficiency improvements to a 30% tax credit, eliminates caps for specific improvements (such as windows and furnaces), and instead establishes an aggregate cap of $1,500 for all improvements placed in service in 2009 and 2010 (except biomass systems, which must be placed in service after the act is enacted). The act also tightens the energy efficiency requirements to meet current standards. For residential renewable energy systems, the act removes all caps on the tax credits, which equal 30% of the cost of qualified solar energy systems, geothermal heat pumps, small wind turbines, and fuel cell systems. The act also eliminates a reduction in credits for installations with subsidized financing.

Click  here to read the whole posting, and to link to additional Federal documents.

A document submitted as a state energy plan falls short of its mark, while renewable energy projects submitted for funding might go too far, legislators said.

Members of the House Energy Committee, including Rep. Jay Ramras, R-Fairbanks, were critical of the Alaska Energy Authority’s state energy plan as director Steve Haagenson detailed the more than 240-page volume during a hearing Tuesday afternoon.

Rep. Bryce Edgmon, a Democrat from Dillingham and committee co-chairman, said calling the report an energy plan was something of a misnomer. Instead, the report seemed a “first step” toward a state energy plan, he said.

Click here to read the whole article.