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

Q: Does it matter what type of wood I burn in my woodstove?

Most species of local wood are suitable for burning in a stove but do not burn wood that has been treated or painted. Regardless of the species, the best wood to use has been properly seasoned and stored. Wood that is fresh, or “green,” contains higher amounts of moisture, which will bring down a stove’s efficiency and cause excessive particulates and creosote buildup inside a chimney.

On a related point, only burn paper in your stove when starting a fire. Too much paper has the potential to produce a fire that is more than a stove or chimney can handle. Burning coal in a wood stove will have the same effect; so do not burn coal unless the stove is rated for it. Overall, avoid burning large amounts of paper or other combustibles that can significantly raise the stack temperature or cause the stove to burn hotter than it is designed to.

Q: I am thinking of installing solar panels on my home or property. What things do I need to think about before I begin?

There are a number of things to take into consideration when looking into a solar power system. First are the cost of electricity and financial incentives. A solar photovoltaic system has a large upfront cost but will provide savings over many years and will eventually pay itself off. Installing a large solar power system and selling the home a few years later will not provide enough time to pay back the investment. However, even pinning down exact numbers for payback can be a challenge since the cost of fuel and electricity both fluctuate. The federal government also provides tax incentives for solar panels and solar thermal systems.

More information can be found at www.energystar.gov. Golden Valley Electric Association’s SNAP program provides incentives as well.

More information on SNAP is available at www.gvea.com/ energyprograms/snap/.

Another challenge is location. Property on the north side of a hill will not collect as much light as a south-facing exposure. Also look at the amount of direct sunlight on a solar panel throughout the day. Shade from trees and other objects will lower the amount of power you make.

Consider the amount of maintenance that goes into a solar power system. Snow and leaves fall on solar arrays and should be cleaned off.

The amount debris can be limited by tilting panels to 49 degrees in the non-snowy months and 90 degrees in other months, which will also help capture more light from the sun’s low angle.

Contact a professional for further information and tips before getting started with an 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

Q: A lot of older homes use pink or yellow fiberglass insulation around doors or windows. If I’m going to reseal any of them, is there a better way to do it?

Fiberglass is a great insulator but still allows air to flow in and out. A can of minimal expanding spray foam will more effectively air seal your doors and windows.

Open the trim around the windows then push the fiberglass in slightly. Make sure the spray foam fills all the cracks for a tight seal. The goal is to make the area around doors and windows as airtight as possible.

Even low expanding foam will swell significantly. Painter’s masking tape can be used to protect finished surfaces from spillage and can be removed once the foam cures. As an alternative, a compressible foam backer rod and silicone caulking can also provide a good long-term seal in difficult spots — especially when if you are working in temperatures too cold to apply foam. Also moisture can affect the foam and it should not be applied to wet surfaces.

Q: When it comes to heat and energy expenses, why are walls such a big deal?

In looking at a home, people often think their roof is where they lose the most heat.

The walls, however, might be a bigger issue.

On a home, walls compose the greatest surface area exposed to the outside. This is important because the laws of thermodynamics teach us that heat will always move to cold whether it moves up, down or sideways. With an exterior wall, one side is always exposed to the cold so heat will naturally always try to move inside to outside through the wall. We tend to assume heat always rises, so our roof must be responsible for the greatest heat loss. What actually happens is that air rises when it is warmed and it becomes a vehicle for the transfer of heat. This does not mean there is any reduction in the amount of heat moving through walls. A home can easily have many times more heat loss through walls than through the roof.

There are many ways to reduce heat loss through walls. The simplest is to carefully caulk and air-seal any places where air can move from the interior or exterior, particularly around windows and doors. Re-insulating walls and adding additional insulation inside or outside can be done if proper techniques are incorporated.

Be sure to consult with or hire a professional before attempting this kind of weatherization.

Remember, a house is a system and what is done to one part of a house may affect overall performance of the home both positively and negatively.

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 the advantages of hot water infloor heat versus baseboard heating?

Radiant hot water (hydronic) floor heating systems’ costs are usually higher than baseboards, however they offer significant performance advantages.

The typical hydronic floor heating system consists of tubing installed in a looping pattern in the floor. This arrangement is specifically sized and spaced to release a given amount of heat from the hot water flowing through the tubes.

There are two primary types of installations, “wet” and “dry.” A “wet” system also is known as “slab heating” and involves embedding the tubing in a poured concrete or gypsum floor. “Dry” systems route the tubing either under or on top of an existing wood subfloor.

Depending on the insulative properties of the floor covering (such as carpet), dry systems may need to operate at higher temperatures to perform comparably to wet systems.

With both types of systems, insulation is often added under the tubing to insure that most of the floor heat travels in the desired direction, rather than into the soils around the foundation.

One of the biggest arguments in favor of in-floor heat is the comfort level. With such a large surface area emitting radiant heat very evenly, most occupants with warm floors tend to feel more comfortable even if the air temperatures are slightly cooler, which in turn may lead to lower thermostat settings.

From the energy savings perspective, hydronic floor heating runs significantly cooler than hot water baseboards.

For instance, the water temperatures in the tubing running through a concrete slab usually range between 80 and 130 degrees F while baseboards operate between 130 and 165 degrees F. Usually, the lower water temperatures needed for slab heating allow the boiler to run cooler.

A cooler running boiler has several advantages, such as less heat loss up the chimney when the boiler is in an off cycle. Similarly, the boiler has less “jacket loss,” where heat is lost from the boiler to the room Cooler water heating can also make the best use of a condensing boiler, which can operate at lower temperatures and generate efficiencies of up to 94 percent.

Conventional boilers top at around 87 percent. When it comes to conventional boilers, cooler operating temperatures produce less system stress, which can extend the service life of certain boilers.

Although the initial costs are higher, the longterm benefits of hydronic floor heating are worthy of consideration, and can also contribute to the value of the home.

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: Many people are fixing their old home and getting a rebate from the state. Is there still rebate money available for building a new home?

The statesponsored Energy Rebate Program for new construction is still active, although continuous longterm funding is uncertain. Any homeowner who builds a home that meets the Alaska Housing Finance Corporation (AHFC) 5Star Plus energy standards is eligible for a $7,500 rebate, however there are some important details that determine who qualifies and a specific process that must be followed.

The program operates from a statewide waiting list on a firstcome, firstserved basis. So the sooner you sign up, the better your chances are for benefiting from the program. The first step is to get on the waiting list. Locally, the staff of CCHRC’s Portal on Retrofits Training and Loans (PORTAL) can guide you every step of the way.

Call 455HEAT (4-328) or contact the AK Rebate Call Center tollfree at1-877AKREBATE (1-877-257-3-228). Once your name reaches the top of the list, AHFC sends out two forms: “5 Star Plus New Construction Energy Rebate Encumbrance Request” and the “5 Star Plus New Construction Energy Rebate Form.” As an ownerbuilder, when you submit the completed forms, you must also include a copy of an energy rating taken from the building plans that validates that the home will meet 5 Star Plus standards, which can be found on the AHFC website: www. ahfc. state.

ak. us. Once AHFC receives and approves the forms, $7,500 is set aside for one year during which the house must be completed.

There are several criteria to meet to be eligible for the program.

Only the original owner qualifies for the rebate, and the home must serve as the primary residence.

If the home is purchased from a builder, it cannot be more than one year old at the time of the first sale. Ownerbuilders can qualify too, however the home cannot be occupied for more than one year from the date of completion.

To qualify if you are an ownerbuilder , you will have to submit the right forms to the state once the home has been completed. These forms include the “Building Energy Efficiency Standard Certification (BEES),” which certifies that the home was built to meet the 5 star Plus thermal and ventilation standards. The form can be signed by a certified home inspector , engineer , energy rater , architect, or the builder if he/ she is approved to certify and has met the current BEES training and testing requirements.

A “Summary of Building Inspection” form must also be submitted, which validates that the home was built in compliance with local building codes. This form must be signed by a statecertified building inspector who has conducted all the inspections during the construction process, starting with the building’s footings. For this reason, it is important to begin the rebate process and hire an inspector before breaking ground on the home. Finally , the finished home must also have an energy audit.

These three forms must be completed, signed by the appropriate authorities, and submitted to AHFC with the reimbursement form. Although this process may sound complicated, the new home construction rebate is a great opportunity for an ownerbuilder or new homebuyer to offset a significant portion of the construction costs, and ultimately enjoy the long term financial and environmental benefits of building an energy efficient home.

Alaska HomeWise articles promote home awareness for the Cold Climate Housing Research Center (CCHRC). If you have a question, email us at akhomewise@cchrc.org.You can also call the CCHRC at (9-07) 457-3-454.

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: I am building a house using post and pad construction. Since it will be off the ground, do I need a plastic vapor barrier under the floor?

Post and pad foundations are a common sight in Fairbanks as they represent one of the least expensive approaches to building on unstable soil — of which we have no shortage.

Usually the floor is raised several feet off of the ground and air flows freely underneath.

It is standard practice in cold climate construction to install a vapor retarder on the “warm side” (indoors) of the exterior walls and ceilings. This is done to keep the water vapor generated in the living spaces during the cold seasons from entering the insulated cavities, where it can condense and lead to mold and rot.

Polyethylene plastic sheeting in a “6 mil” thickness is typically used for this purpose, and is mandated by local building codes.

With post and pad construction, it may seem logical to also install plastic sheeting over the tops of the floor joists, before laying down the subfloor sheathing. In some cases however, it can do more harm than good.

If any rainwater leaks through the joints in the subfloor before the roof is on, it will be stopped by the plastic, and the floor may not be able to dry quickly enough to avoid mold and decay. The same risks hold true if liquids are spilled on the floor once the house is finished, or if a major plumbing leak occurs.

The plastic also prevents the use of subfloor adhesive between the joists and sheathing, which is designed to prevent squeaks in the floor.

Modern subfloors are usually sheathed with industrystandard 3/ 4 inch tongue and groove exteriorrated plywood or oriented strand board (OSB).

With post and pad construction, the subfloor sheathings are in an area that is comparatively less at risk for water vapor issues.

This is due in part because warm indoor air leaves at the top and is replaced by outside air drawn in at the bottom, so water vapor moves upwards — away from the floor.

In addition, the combination of thickness and types of glues used in 3/ 4inch plywood and OSB subfloor sheathings means they are less likely to absorb any moisture that might be forced into the house.

To minimize air leakage through the floor, the unsupported seams can be caulked with an adhesive sealant such as a silicone that is rated to have a good bond strength with wood.

The decision of whether to use or omit a plastic vapor retarder in floors using post and pad construction ultimately rests with the engineer or the local code official who may have reasons specific to the project or building site.

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

By CCHRC Staff

Q: How can I get rid of carpenter ants without using toxic chemicals?

Carpenter ants are tenacious creatures and once they start a nest, they can be difficult to eradicate.

Prevention is always the easiest solution.

If you can keep them from establishing a foothold, you will be better able to protect home and property. Remove any wood scraps and tree stumps from around your home.

Sheets of plywood, old tarps, pallets and anything else that provides ground cover, particularly if it is moist, can provide a staging area that will bring ants that much closer to your home.

Once they gain entry to the house at ground level, ants will often start a nest in an area that is damp or prone to decay. Many times the infestation starts at the foundation. Crawlspaces and basements, and any spots that may be prone to moisture damage, will be especially attractive. Rim joists, areas where decks are attached and areas around improperly flashed windows present places that allow the ants to get started.

The ants do not eat wood, but tunnel into it to make their nests. As a result, rigid foam board, which is often used around foundations, also presents an appealing target.

Even though ants prefer moist areas, they are not limited to that environment and will expand their nest building into walls, floors and even work their way into roofs.

A mature carpenter ant colony will have a main nest and satellite nests, which the ants use to broaden their foraging grounds. If the ants can be traced back to the main nest in the woods, then a localized dose of ant poison can be very effective.

Chemical poisons may work well, however they are the least desirable from both a health and an environmental perspective, especially if there is a chance that pets or children could come into contact with them. Many ant poisons are extremely toxic and if you are considering buying a product, research the long term effects and handling precautions online.

Some insect poisons may break down slowly and can be absorbed into the food chain by nearby plants and animals or dispersed by rains and groundwater. So if the main nest cannot be located and safely isolated, sprinkling poisons liberally around the grounds in the hopes it will kill the ants should be avoided. Generally, chemical ant control should be left to a professional who will be able to determine which product is best suited to a particular application.

A lot of the ant baits sold in the stores are designed for Lower 48 species of ants, and the primary attractant is sweets.

Carpenter ants are foragers that eat proteins (such as insects), so sweets will not appeal to them in the same way.

Occasionally, a carpenter- ant-specific bait will make its way on the shelves, and these can be effective. If you buy an ant bait station and leave it exposed, it may attract pets, squirrels, voles and other animals.

Before you begin an ant control strategy, check with a local exterminator. Some exterminators may have access to effective carpenter ant baits and contact poisons which are not available in stores.

When it comes to nontoxic products, diatomaceous earth is available at many feed and garden stores. It acts as a physical killer rather than a chemical killer by working its way into the ants’ breathing tubes and joints. When the ants clean each other, they can also transfer it among themselves. Again, it will do little good putting it on individual ants, you must find a nest.

The presence of ants can create problems in every part of your home, and repairing the damage can be expensive, so the sooner you eliminate ants, the better.

More information on combating carpenter ants is available at the University of Alaska Fairbanks Cooperative Extension Service at www.uaf.edu/ces/.

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.