By CCHRC Staff

Q: I understand it is important to get fresh air into my house, but exchanging air in my home means the warm air is going out and cold air is coming in. I pay quite a bit to heat my home and reheat all that air coming in. Can air exchangers help to solve this problem?

There are several types of air exchangers on the market, but not all of them capture heat from the outgoing stale air.

Commercially available exterior wall vents combined with a fan designed to operated all the time will provide fresh air for a home.

These devices are the least expensive, but provide no heat recovery feature.

A heat recovery ventilator (HRV) is a more expensive device that has a heat exchanger inside, where the air flowing out of the home passes by the air flowing into the home, without mixing the two. As the warm air moves out, it transfers some of its heat to the cold air moving in.

The heat recovered by this process is in the 60 to 75 percent range, which is significant because any amount of heat that is recovered represents air that the homeowner does not have to pay to reheat.

As the cost of fuel increases, this savings will be more significant.

An energy recovery ventilator recovers heat and moisture as well. Unfortunately, these systems cannot be used in the Fairbanks area because extremely cold air will freeze the device.

Many Interior Alaska residents are retrofitting their homes now.

Adding insulation and tightening a house makes ensuring you have good indoor air quality more important than ever. Insulating a home will conserve heat and adding an air-exchanging device will clean the air.

But only an air exchanger with a heat recovery option will do both.

Be sure to consult with a licensed professional to help design and or install any ventilation system.

Q: When should I start plugging in my vehicle?

Many of us will start plugging in our vehicle right away when it gets cold but plugging in will have an unfortunate affect on our electric bill.

The Alaska Department of Environmental Conservation provides the rule of thumb: plug in for at least a couple hours before starting the vehicle when it is 20°F or colder.

At that temperature, you can get by plugging in for less time, and as it gets colder you need to plug in for progressively longer.

If you find you need to leave your car plugged in substantially longer than these guidelines before it starts smoothly, then you car may need maintenance.

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

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.

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 are my options for eco-friendly decking?

In today’s market, the selection of decking materials is vast and can be overwhelming.

Other than wood or treated wood — which have been traditional materials for years — there now exists a wide variety of composites which may contain a combination of synthetic materials.

Composite decking is typically comprised of some type of plastic or vinyl, and in addition, some brands also will also use ingredients derived from wood products. When it comes to treated woods, the chemicals used in the treatment process have gotten more eco-friendly than the chromium copper arsenate (CCA) which dominated the industry for many years. Be aware that the new treatments tend to be more corrosive to metal fasteners, so today’s treated woods may require a specific type of treated connector in order to insure that the deck will hold together safely in the long term.

Composite decking may contain recycled plastic and/or recycled wood fragments. Some brands may even be composed almost entirely of reclaimed products. Common recycled ingredients include old pallets, mill waste, plastic shopping bags, bottles, and other discarded plastics. One of the primary advantages of composite decking is it requires little or no maintenance. Not all composites can span the same distances between joists as wood decking, and so may require additional framing for support.

Most local lumber yards will carry both wood and composite decking. A good resource which compares decking and other products is the website www.healthybuilding.net.

The site has lots of information on a number of different building materials.

Q: I have a heat recovery ventilator in my crawlspace, and it’s starting to make funny noises, what should I do?

HRV systems require routine maintenance, and if the maintenance schedule is ignored it can severely impact performance.

For regular maintenance, examine the filters, outside hoods and screens for cleaning or replacement every one to three months. Filters can become clogged with organic debris including insects, pollen or dust and grass, especially if the fresh air intake is close to the ground.

Most of these filters are washable.

The exchanger core also needs regular maintenance. It should be inspected approximately every six months and cleaned as necessary. The core can be vacuumed or washed with soap and water depending on the situation, so refer to the owner’s manual for specifics. Also, be sure to examine the condensate drain, and if needed, clean it at the same time. The lines can be tested by slowly pouring water into the drains to check for obstructions.

The HRV drains should have a trap or a loop containing water, which will prevent the unit from drawing in air through the line.

Testing the lines is important because the HRV is sometimes tied into a septic line for drainage, or is located in a crawl space with other plumbing. Consequently, if there is a problem with the drain, the HRV system may suffer the ill effects.

Also, fans need to be checked every three to six months. Many fans are designed to function without lubrication, but some HRV fans require it, especially the older models.

Another important point is to make sure the HRV is “balanced.” That means it should be taking in roughly as much air as it is exhausting so as not to create pressure problems in the house. If you are not sure that the system has ever been professionally balanced, this is definitely a step worth taking to insure the system is operating properly.

Most manuals will contain information regarding maintenance specific to that particular brand and model of HRV. If you have lost yours, typically there are only a few different brands in Fairbanks and those manuals are usually available online.

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 questions Fairbanks residents have about building, energy and the many other parts of home life.

Q: What is the relationship between boilers and combustion air?

Any appliance that expels air must have its own air supply or one appliance could be drawing air through another. When a boiler expels gas out its flue, an equal amount of make-up air must be brought in. Similarly, any appliance that sends air out of the house needs to be supplied with intake air. If an appliance is not supplied with intake air, it may pull the air it needs down through the boiler’s chimney, thus “backdrafting” the boiler and pushing combustion gasses into your home.

For example, in a “tight” home (one with sound insulation and well-sealed doors and windows), where a wood stove and a boiler both draw air, the boiler may get its air supply by backdrafting the wood stove. However, if you have provided adequate air supplies for both appliances, both should operate with no problems.

Q: If one of the panes in my double or triplepane window breaks, can I get the pane replaced, or do I need to replace the whole window?

When one of the panes in a double or triple pane window breaks, all of the glass layers must be removed and replaced.

Taking apart a window also involves removing several parts such as the “stop” which holds the glass in place, the jamb liner, and other components.

Typically the frame and any associated trim can remain untouched. Virtually all factory- built vinyl, fiberglass, and wood windows have provisions for removing the glass.

If the window can open, simply disconnect the opening portion from the frame and take it to a glass shop.

Repairing a “fixed” or “picture” window can be more complicated. Wood windows may use screws and be relatively easy to replace, however removing the glass from vinyl or fiberglass units is less obvious. In many cases, this involves a “snap in” type window stop located either on the inside or the outside of the window, separate from the main portion of the frame.

Generally, this type of repair is best left to professionals, since removing the stops can be difficult and can result in more broken glass.

Sometimes the window stop will be adhered to the frame with two-sided glazing tape or adhesive caulking.

The replacement glass not only needs to be the proper length and width, but also the proper thickness and space between the panes. If a glass shop replaces the glass, they will provide a guarantee, which in itself is worth piece of mind.

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

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.

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

For starters, there are the basics of electrical safety: when you are plugging in anything, you do not want to make direct contact with the circuit because of the risk of electric shock. Besides that, a lot of Fairbanks car fires can be attributed to improperly maintained vehicles. Oil leaks, fuel leaks or other heating elements can be ignited by a small spark. Because winterizing cars in Fairbanks includes installing electrical heating devices, people need to be more cautious about leaks because of the risk of fire.

So if you have leaks, get them checked out and perform any other standard car maintenance.

Could those work in Alaska?

The shingles are going to be covered with snow, so how will that factor into their

East or west might work too, depending on how your roof is built and the pitch of the roof. Consider all the options before choosing a system.

A Heat Recovery Ventilator, or HRV, is designed to bring fresh air into your home. The “tighter” your home is (fewer leaks in insulation, doors and windows), the more essential an HRV is to the safety of the occupants. The other important part of an HRV, heat recovery, means it captures as much of the heat that is leaving the building as possible. You have already heated the air in the house.

To bring fresh air in, you are going to have to expel stale air, but that air has heat in it that you do not want to waste. So the HRV acts as a heat exchanger. As cold fresh air moves in, the warm stale air moves out. When the two air flows pass by each other, the heat from the warm, stale air is transferred to the cold, fresh air through a heat exchanger. These devices will help keep your home warmer in the winter, while saving you energy and money because you do not have to reheat the air coming into your home quite as much.

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.

Susan Carpenter breaks California state plumbing code three times a week. Her accomplice is her washing machine. Rinse water from washing machines usually goes into the sewer — so what if you could recycle it? That’s what Carpenter does, using it to water plants at her Southern California home.

“The washing machine is filling up with water, and it is going through its normal process of washing clothes,” she says. “And after about eight minutes, you’ll start to hear it spin and we will run outside and see it squirting through the tubes.”

The “it” is gray water, which looks like its name — a bit gray, a bit cloudy. After all, it’s the wastewater from bathtubs, sinks and washers.

The gray water lapping up Carpenter’s dirty clothes will soon be lapped up by her passion fruit trees — and no, the fruit won’t taste like Tide. She uses a special type of detergent that doesn’t contain salt or boron, compounds which dehydrate plants.

Click here to read (or listen to) the whole story.

Alaska’s energy resources amount to more than the oil and gas that have so much transformed the state during the past 40 years. One largely untapped resource is wind power. Large-scale operations, such as a growing wind farm in Kotzebue and plans for a 1.5 megawatt wind farm on Fire Island near Anchorage underscore the potential of wind energy in Alaska. But what about residential wind power?

Wind power can help make your home more energy independent, cut your fuel bills, and reduce air pollution. Best of all, wind power keeps giving and giving, with no emissions and minimal maintenance. So, yes, investing in wind power can make financial sense if your home is ideally located where there’s wind. But the costs can be high initially. A medium-sized system sufficient to meet most of an average home’s needs will run between $10,000 and $20,000 professionally installed.

Though wind generation is generally considered environmentally friendly, you should check local codes, covenants, and other possible restrictions before investing any money. Especially if you have a smaller lot, it’s a good idea to take your neighbors into consideration. An acre or more of space is advisable to ensure the equipment is far from other structures. Although not nearly as tall as cell phone towers, small wind generators tend to attract attention and produce at least some sound. Modern generators are quieter than older models, however, and are usually not much louder than other normal outdoor sounds.

It’s difficult to generalize about how well a particular wind generator will work for a given location due to variables in size, design, and the wind speed for your specific location. But, in Fairbanks, wind generators are not practical within the city limits. The wind in the Fairbanks region tends to blow near the surrounding hills or in the large flats out in the borough.

Wind resource maps are available to indicate whether your house is located in a suitable area, but it is important to measure the specific wind characteristics of a site using an anemometer and record averages over a several month period to justify your investment. Typically, monthly wind speeds should average 8 miles-per-hour (mph) to 14 mph for a unit to make economic sense.

A basic wind generation setup consists of three components – the rotor-driven turbine, a tower or other mounting apparatus, an inverter to transform direct current to alternating current or a battery bank if you’re not connecting the generator to the electric grid. Depending on the equipment and wind, residential turbines can generate between 100 watts and 100 kilowatts. Towers are usually 80 feet or taller and wield rotors 8 feet or more in diameter. As a rule of thumb, higher towers result in more power. These towers can attach to foundations or be supported by guy wires, which is a relatively inexpensive method that can work well in Fairbanks’s shifty ground.

Wind-generated power can also be sent to your local electricity provider’s power grid. In much of Fairbanks, this is accomplished through the Golden Valley Electricity Association’s Sustainable Natural Alternative Power (SNAP) program, which helps offset the cost of installing the equipment and supports local alternative energy production. The federal government helps, too, by offering a tax credit of up to 30 percent toward the cost of your small wind generation system.

Wind generators can be installed professionally, providing you with the benefit of expertise and service support, or you can order kits to install yourself. The electronic and structural components do not require a PhD in physics to understand, but they are somewhat complicated and require adherence to safety and common sense. In some cases, a licensed electrician might be necessary.

There are many resources online to help you investigate wind power, but here are two to get you started. Locally, check out the Alaska Energy Authority’s webpage on wind power. The American Wind Energy Association has a wind energy “toolkit” with national resources.

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

“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