Tag Archives: Energy Focus Articles

Air exchangers work but study up on them

ASK A BUILDER

By CCHRC StaffQ: 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.Q: When should I start plugging in my vehicle?

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.

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.

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.

Time to get all decked out

ASK A BUILDER

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.

Make home repairs now while weather is good

ASK A BUILDER

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 want to inspect my home this summer, just in case there are any repairs I should make.

What kind of things do I want to look at?

The parts of your home that have moving parts or are exposed to hot or cold are most likely to need maintenance.

To begin, inspect your windows to make sure they open and close properly and seal well. Look at door and window hinges and related gasket seals and check for any condensation or breakage between your window panes. Inspect your chimney, which will prevent potential stack fires and will also improve efficiency. Especially inspect where your chimney goes through your attic and roof.

Have your boiler or furnace inspected for proper functioning and change your fuel filter if you use oil heat. Replace any air filters, including those in your heat recovery ventilator.

Check to see if your foundation exhibits any signs of cracking or movement, which is a sign of shifting soil or settling. Look at the exterior walls and roof of your home for any deteriorating siding or roofing. Fading, peeling paint or corroding roof tiles are an indication you may need to replace roofing, or treat or paint your home.

Inspect your attic and crawlspace for problems, especially moisture. Have your septic tank pumped. Add salt to your water softener and change water filters. Replace batteries in your smoke alarms and CO2 sensors and make sure both are working properly.

Remember it is easier to make repairs such as these in the summer than in the winter. Putting off home maintenance is tempting to do on a bright sunny day, but you may pay for it later with time, money and convenience.

Can I break my wind turbine or overload the system?

The Fairbanks area does not often get extremely strong winds, so overburdening a wind turbine system is unlikely.

Wherever you live, you want to be sure your turbine is properly sized. Do not settle for an inexpensive turbine and hope for the best — purchase a durable model rated for those conditions.

When shopping for your system, note that some are designed to cope with irregular conditions.

If the turbine is connected to the power grid it will put power onto the grid and not overload. Some systems will even shut down to avoid problems from extreme high winds. No matter the situation, consult with a professional before you begin any wind project, make sure to choose the right turbine for your area and perform regular maintenance as specified by the manufacturer.

Stock up that refrigerator — it could save you money

Ask a Builder

By Cold Climate Housing Research Center Staff

Q: I heard a full refrigerator uses less electricity. Is that true?

When it comes to fridges and freezers, always try to keep them full. These appliances measure the temperature in the storage space and adjust to keep that temperature below a certain level. The more empty space, the more energy needed to keep that space cold. Since it is not always possible to keep your refrigerator or freezer full, it helps to fill up old milk jugs with water and put them inside to take up space.

Q: What are my options for putting insulation on the outside of my house?

Locally sold rigid foams work quite well. White foam, which is expanded polystyrene, or EPS, and blue and pink foams, which are extruded polystyrene, or XPS, all work well. Foil-faced foams also work well and have the highest R-value. The foil facing also makes them impermeable to moisture.

Remember, any time foam is applied to the outside of a home, it will make the home much “tighter” — the building will have fewer cracks and holes.

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.

Alaska BEES; problems with wood burning

Alaska HomeWise: Ask a Builder

By Cold Climate Housing Research Center 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.

I have heard of the BEES regulations in Alaska, though I don’t know quite what they are. Is this something I should know about if I am a homeowner or want to build a home?

The BEES (Building Energy Efficiency Standard) regulations are part of the compliance requirements for any home built to Alaska Housing Finance Corporation’s (AHFC) cold climate construction standards. More recently, AHFC has adopted the International Energy Conservation Code and amended specific portions of it for construction in Alaska. Because we are a colder climate, AHFC has set higher insulation values for windows, floors, roofs, walls, and other areas. There is also an energy credit for building a home that meets AHFC 5 star plus requirements. In addition, a mortgage rate reduction is possible through AHFC when purchasing a four or five-star home that meets current AHFC BEES standards. When considering this credit, make sure to start the paperwork and have a state certified inspector on board before breaking ground. Also, local contractors should be familiar with the AHFC requirements, so ask before you start building.

The BEES regulations can be found on the AHFC website and are arranged by region. For each area of the state, the minimum insulation requirements are listed for windows, walls and other parts of a home. The statewide recommendations for ventilation are also covered. What is important to remember, is that the BEES regulations are minimums and more insulation is still beneficial in many cases.

The current AHFC requirements can be found here: http://www.ahfc.state.ak.us/iceimages/reference/bees_amendments.pdf

A lot of the problems with burning wood have to do with moisture content. Tell me more about that.

The higher the moisture levels in the wood, the more heat energy is going to be required to turn that moisture into water vapor so it can exit the wood and allow it to burn. Essentially, burning wet wood, or fresh-cut “green” wood is wasting energy because the fire is not burning hot enough and creates more combustion byproducts while trying to get rid of moisture. The end result is creosote and ash that can build up in your stove and stovepipe. In addition, because the wood is not burning completely, the smoke it creates has a higher amount of fine particulate material known as PM 2.5, which can be hazardous to health.

To combat moisture, wood must be dried sufficiently. Wood should be split, stacked and covered in the summer months so that it is ready when needed. A woodpile should be protected from precipitation, but the sides should remain exposed to allow the stack to continue drying. A moisture content of 20% or less is ideal. Green birch and aspen can contain up to 80% moisture by weight. The inefficiency of burning anything over 20% moisture leads to progressive increases in creosote and particulates.

If you want the full story on wood-burning in the interior, along with a wealth of information regarding proper burning techniques, the Fairbanks North Star Borough is putting on two open houses on wood burning and PM 2.5 next week. The open houses take place Tuesday, April 13th at the Morris Thompson Cultural and Visitor’s Center and Wednesday, April 14 at the North Pole Middle School cafeteria.

Decoding dust patterns; stovepipe clearance; Fairbanks building codes

Alaska HomeWise: Ask a Builder

By Cold Climate Housing Research Center 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.

My walls have black lines where dust has collected. What could cause dust to collect in this pattern?

One telltale sign that you have heat loss through the framing in your house is that the studs will be outlined in black lines on interior walls. This is what happens when moist indoor air condenses on the cooler portions of a wall where the studs are located. Air carries tiny little dirt particles, so as moist air condenses on those studs, the particles accumulate on the wall and begin to show over time.

These black lines are a sign of significant heat loss in a building, but there are steps you can take to reduce this heat loss, including retrofitting your walls or reducing the amount of moisture in your home.

Any suggestions on how much airspace to leave around my stovepipe?

One of the biggest issues associated with houses burning down is that not enough clearance is left around the stovepipe, or insulation is stuffed right up against the pipe. After years of the insulation or wood constantly being exposed to heat, the ignition point of that material drops, and it takes a lot less heat for it to catch on fire. One hot stove fire, or worse a chimney fire, could ignite that material. If you are able to get into the attic, take a look at the pipe and make sure it has the required amount of clearance between the chimney and the insulation or chimney and the rest of the structure. Typically there should be at least two inches of air space around the pipe. If there is any doubt, or if there has ever been a chimney fire, consult a chimney sweep.

Where can people go if they want more information on Fairbanks building code?

The best thing to do is call the City of Fairbanks Building Department or visit them online at www.ci.fairbanks.ak.us/departments/building/building.php. The website has a lot of information regarding the permitting process, local amendments, typical details for foundations, and much more. Remember, building codes vary from city to city and they do change often, so review them, especially the local amendments, in case something has changed.

Also, if you are looking for advanced energy standard information the Alaska Housing Finance Corporation has developed Alaska-Specific Amendments to the International Energy Conservation Code 2006 and American Society of Heating, Refrigerating, and Air-Conditioning Engineers Standard 62.2-2004. These are a great place to start if you want to build an energy efficient home in Alaska. http://www.ahfc.state.ak.us/iceimages/reference/bees_amendments.pdf

Metal-framed windows in Alaska; problems with heat pumps; woodworking with birch

Alaska HomeWise: Ask a Builder

By Cold Climate Housing Research Center 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.

I heard that metal-framed windows are a bad choice for Alaska. Why and what should I do about it?

Most metal-framed windows are made from aluminum which is a highly conductive material. The laws of physics dictate that heat will always move in the direction of cold. When the temperatures drop outside, the aluminum acts as a pipeline, moving heat from inside to outside. Also, a colder window is more sensitive to moisture and will gather condensation.

Replacing metal frames is the preferable thing to do, however, not always practical. Fortunately, there are some other easy solutions. Covering the inside face of a window with a shrink wrap will create dead air space that will help keep the window warmer. Curtains and shutters will help as well.

I am thinking of putting in a heat pump system for my home. What types of problems are associated with heat pumps?

While they are a proven technology in the lower 48 states, heat pumps are still a relatively new technology in the state of Alaska. Heat pump performance can vary significantly with different soil conditions and site exposures. As a result, installations need to be evaluated on an individual basis.

When installing a heat pump system, caution must be taken around foundations. Installing a system too close to a foundation can increase the risk of potential permafrost problems, such as frost jacking. There is some question as to how a heat pump will work over time if it removes more heat from an area than can be replaced by surrounding soils and seasonal conditions, especially in Alaska where ground temperatures are cooler to begin with. On the positive side, there are methods to curb excessive cooling, such as adding a solar thermal collector to recharge the ground during the warmer seasons. This is also a proven technique, though, again, it has yet to be proven in Alaska.

Installation cost is another consideration, as the systems themselves can cost between $10,000 and $20,000. For the time being, heat pumps are showing good potential but we still need more trials in Alaska’s cold climate to give a definitive answer.

Do you have any advice for woodworking with local birch?

Birch is not used for framing and structural applications the way spruce is, but it does lend itself well to finish work. Birch has a lot of color. The heartwood can be very dark while the sapwood can be very light. In addition, the grain is rarely straight which gives the wood a ‘figure.’ After varnishing, the combination of colors and grain can be quite eye-catching. Each tree is unique and especially with birch, there can be big variations in wood appearance from one tree to the next. As examples, birch can add wonderful highlights to kitchen cabinets, and floors.

Birch is denser than cottonwood or spruce, making it better suited for stairways and tabletops. When working with birch, make sure there is plenty extra so any undesirable defects or twisting can be milled out or replaced. When it comes to panels and drawer fronts it is a good rule to varnish both sides and the edges, to keep the wood stable. As humidity changes over the seasons, moisture will penetrate an unvarnished side to a greater degree, which can cause warping.

Insulating your septic tank; identifying permafrost; putting up a wind turbine

Alaska HomeWise: Ask a Builder

By Cold Climate Housing Research Center 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.

Recently, I was scoffed at for wanting to insulate my septic tank when I install it next summer. How much insulation is necessary for a septic tank?

Septic tanks contain bacteria that will break down septic sludge. These organisms will do much better in a warm environment than a cold one. There is some debate on how much insulation makes a difference when it comes to soil temperature and bacteria performance. However, a bigger concern is a septic tank freezing because it was not buried deep enough, or does not have enough insulation to protect it from cold air. A frozen septic is more likely in the winters of extreme cold with little snow. In that case, the ground freezes very hard and very deep.

When in doubt, it is cheap insurance to add a layer of rigid two-inch foam insulation on top of the tank and a few feet down on the sides. In fact, insulating a septic tank is a good way to use up all the damaged or left over pieces of foam from a jobsite. Another alternative is to have the top of the tank sprayed with several inches of polyurethane foam. Do not forget to consult with the Alaska Department of Environmental Conservation for the most recent codes for insulating a tank.

Is there a way to tell if land is full of permafrost just by looking at it?

There are some visual indicators, but they are not 100% reliable when determining whether or not land has permafrost. For starters, look at the other houses in the area and the types of foundations they have. If there are a lot of houses on posts, or if houses with conventional foundations are sagging, that could be a sign of permafrost. If the land is down in the flats or on the north side of a hill and has mostly little black spruce trees and moss, that often indicates ice in the soil, because the land cannot support a big root structure. Sometimes a piece of land can have good-looking ground but permafrost underneath at a low depth or ice lenses (pockets of ice) only under small areas.

Not everywhere has a lot of wind, so when is putting up a wind turbine system practical? ?

You can still put up a turbine, but it is important to have a good wind resource. If you are connected to the electrical grid, you want to have average wind speed at about ten miles per hour or better. Of course the cost of electricity for your home will dramatically affect any possible payback of putting in a wind system. If you are in a village and paying 60 cents a kilowatt hour for power, then having “enough’” wind is going to be different than if you are in Anchorage and paying eight cents a kilowatt hour for power. Look at how much energy you are likely to produce annually, how much money you will save, and the cost of installing a system – all before deciding if a wind system is cost-effective.

Maintaining your chimney; truth about oil-fired condensing boilers

Alaska HomeWise: Ask a Builder

By Cold Climate Housing Research Center 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.

How often should I clean my stovepipe?

How often a chimney or stovepipe should be cleaned is case dependent. If you have more than an eighth inch of creosote buildup inside, it should be cleaned out. In order to determine how often you should clean your stove, burn wood on your regular schedule and go on your roof and look down the chimney pipe every so often. After some time you will see creosote buildup on the inside of the chimney. Clean out the stack and continue your schedule. With regular monitoring, you will start to get an idea of how quickly the stack builds creosote and how often you need to clean it.

In addition, if you have just bought a house that has a chimney and a wood stove, make sure you get a thorough inspection. Just because a stove did not burn the house down previously, does not mean it will not happen to you. Get as much information as possible about how the stove operates and if every component is properly sized before you start using it. Be especially wary of a stovepipe that goes through a back wall rather than up through a roof. Pipes that go through a wall have more problems with drafting because they bend after coming directly out of the stove, which reduces airflow. They then go immediately outside where they are not insulated, so the combustion gas cools quickly and has a harder time exiting. Sometimes this configuration can create a “cold plug” because it takes a lot of energy for the stove to warm up the pipe and create a proper draft. Cold plugs can contribute to backdrafting as well. Any time smoke does not exit the pipe properly, it can also create more creosote.

I heard that the condensate produced by new oil-fired condensing boilers contains “strong acids” and they should be avoided for that reason. Any truth?

The CCHRC facility has a Monitor FCX oil-fired condensing boiler. We use a site-made trap of black ABS 3 inch drain fittings filled with limestone chips. This neutralizes the condensate before we discharge it to the sewage treatment plant that is in the basement of our facility. We have had no problems at all with the condensate from our boiler.

The LifeWater Engineering facility is heated by a Monitor FCX oil-fired condensing unit with the condensate drained directly into the sewage treatment plant the serves that facility. They have not been able to detect any change in the ph of the waste water system with the addition of the acidic condensate. The boiler itself uses a high grade of stainless steal and polypropylene exhaust components that can handle the acidity without any problems.

The acidity of this condensate is around that of very acidic wine. A ph test strip for pool water or hot tub water would give you some info on the acidity of the condensate from the fuel you are using.

Prevent heat loss with exterior insulation

By Cold Climate Housing Research Center 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.

These days, it is popular to put foam insulation on the outside of buildings. How did all this come about?

A building loses heat through its framing, which is called “thermal bridging.” Wood has less insulative value than any kind of insulation. For instance, a wood stud has an R-value of 1.25 per inch. If a building has a standard framed wall, whether it is 2×4 construction, or 2×6 construction, the studs span from the interior of the wall to the exterior of the wall. For a 2×6 wall, that would give you an R-value of about R-7 where the stud is located. If you were to take all the studs in a wall and stack them side by side, you would have a wall that is 11-25% wood depending on how it is built. Even if a wall is full of R-21 fiberglass insulation, the insulative value of the wall is dramatically worse when you average in the less insulative value in the wood.

At least 20 years ago builders began experimenting with putting insulation on the outside of homes as a way to stop heat loss created by thermal bridging. Adding foam to the outside of a wall “wraps” your home in a continuous layer of insulation, thus preventing other building materials from conducting heat to the outside and cutting down on the air leaking out of your house. This technique has been used in many cold climate regions. The PERSIST (Pressure Equalized Rain Screen Insulated Structure Technique) is an exterior insulation technique that has been used in Canada for many years, while the REMOTE (Residential Exterior Membrane Outside Insulation Technique) Wall System is popular here in the Interior.

Where can I recycle glass in the interior?

Recycling glass is a challenge because the material is heavy and difficult to ship out of Fairbanks and then out of Alaska. Also, Anchorage recently ended their glass recycling program, in part because the market for glass is currently not very good.

Here in Fairbanks, there are a few small artisan-type businesses that are reusing glass, but they cannot handle large volumes and typically have more than they need already. However, the Borough Recycling Commission is looking at ways to use glass here locally potentially as road fill and construction fill. These plans will take time to develop, so if you have any input, contact the Recycling Commission through the Fairbanks North Star Borough at 459-1000.