Tag Archives: Energy Focus Articles

Construction industry working to limit offgassing

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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 offgassing and is it something I need to worry about?

Offgassing, also called outgassing, is a term used to describe any chemical compounds or irritants that are emitted from something. Any building products such as plywood, paints or carpets, construction glues and varnishes can emit chemicals for extended periods after they have been installed. Offgassing is common in solvent-based or petroleum-based products. Good ventilation is an important factor in combating offgassing.

Current building codes require mechanical ventilation in new construction to ensure that a house gets enough fresh air. If you want to build an eco-friendly home, or you have chemical sensitivities, look into building a home with little to no offgassing components. In the big picture, the construction industry is changing the way it manufactures products in order to limit or eliminate the use of materials that offgas.

Q: What’s an acceptable temperature to keep my garage at throughout the winter?

If the house is attached to the garage, you will want to keep it a little warmer, about 50 degrees.

In many cases, if you have a boiler and pipes in the garage, they may warm the garage more than you want just from the heat they give off, especially if your boiler is an older unit. Since it is not living space, if you have a garage that is 70 or 80 degrees, you may be using a lot of energy to heat that space. Also, that is a lot of heat that could be leaking out through the walls, which adds up to wasted energy. Don’t heat your garage anymore than you have to because it is a wasted expense.

A cooler garage is a good place to keep a refrigerator or freezer.

Keep the temperature at 60 to 40 degrees, or whatever your comfort zone is. On that note, if you are seeing a lot of condensation in the garage, which can happen by parking a wet vehicle inside, you might want to keep the temperature a little warmer or ventilate more.

Q: If I am interested in putting up a wind turbine.

Is this something I can do myself?

Installing a wind turbine is not that hard, but you definitely want to do it right or it will become very hard and very expensive. Even if installing the tower goes well, you are talking about lethal voltages of electricity, just as in any home. You don’t have to be a trained professional to do it right, but it’s prudent to work with people who are trained to install such specialized equipment.

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.

Get the LED out (they work well)

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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’ve read LED lights perform well in cold temperatures. What about in Alaska?

Absolutely. LEDs are generally pretty tough. They are shock and cold resistant. In fact the colder it gets, the better they perform. When it comes to outdoor lighting at extreme temperatures, some fluorescents can suffer from performance losses when compared to their use inside. Currently, LEDs are popular in lowlight applications such as pathway lighting or for task lighting such as workbenches, nightlights, flashlights and other devices where incandescent bulbs have traditionally been used. Because small incandescent bulbs are the least efficient, they are perfect to be replaced by an LED.

When it comes to the lighting industry in general, changes are coming along quickly. Prices are coming down on LEDs and fluorescents, and they are being better designed to work in different environments. If you are looking at buying an LED light for outdoor use, get one with a good warranty. The bulbs may last a long time, but there are other components in the light that may not fare as well.

Q: What is the difference between EPS and XPS foam?

Both are similar chemically and both are made from polystyrene, but the manufacturing process is different. Expanded polystyrene (EPS) foam, also called “bead board” is what you would find in coffee cups.

It is manufactured using small plastic beads that are expanded and fused together in a mold. Extruded polystyrene (XPS) is blue or pink, hence it is also called “blue board” or “pink board.” It is also made using polystyrene beads, but they are liquefied rather than expanded and then a blowing agent is added to force the liquid into a form. This process also creates a skin on the surface of the foam.

XPS is slightly more resistant to water vapor than EPS. EPS, generally has an R-value of 3 to 4 per inch, whereas XPS has an R-value of about 5 per inch. No matter what type, the R-value will be printed on the packaging or the board itself.

It is often assumed that the blue or the pink foams are the only ones you would want to use “below grade,” such as in your basement or a damp environment. The truth is both products will work as long as they are strong enough or dense enough to handle the stress in the place they are going to be installed. For example, many insulated concrete forms are made with EPS foam. These forms always go below grade. No matter the case, consult the product manufacturer information, which is usually available where you purchased the foam. Also, judge the prices in relation to the R-value you are getting, and get a product that is rated for your application.

Ventilation is key when fighting condensation around your home

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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: How can I keep condensation off my windows in the winter?

Condensation is a product of the relationship between humidity and temperature.

The warmer the indoor air is, the more water vapor it can hold. When the air moves next to a window it can no longer hold the same amount of water vapor because the temperature is colder close to the window. This is when you start seeing condensation forming. As an example, if your indoor temperature is 70 degrees and outdoor temperature is 0, then moisture will begin to condense on a single-pane window when there is roughly 15 percent relative humidity in the house. A double-pane will be subject to condensation at around 25 percent to 40 percent humidity, and a triple-pane will fall into a range of around 30 percent to 50 percent. These number ranges are based on average window insulation values.

A really good triple-pane window may be able to withstand significantly higher humidity levels before condensation occurs. The target humidity levels for occupant comfort in a home range from about 30 percent to 50 percent, however the lower end of this spectrum is considered safer in cold climates such as ours, due to concerns with condensation within walls and ceilings. When the humidity is really low, some people become prone to respiratory infections. Of course high humidity can cause similar problems with bacteria and mold growth in the building. As the winter air in Fairbanks is so cold and dry, it is usually difficult to attain anything close to 50 percent humidity in a properly ventilated house.

To keep condensation off windows, make sure your home is properly ventilated.

The presence of excess moisture around windows is a good indicator of the effectiveness of ventilation in your home. Shoot for the low end of the target humidity range, to keep both you and your home healthy.

Q: Can I face repercussions if my home is violating building code or it is out of date?

In Fairbanks, building inspectors primary focus is on new construction and remodels. When you are remodeling a home that is not built to code, inspectors only require that any new work meets current code.

Older parts of a building that are not involved in the remodel are not subject to same requirements, unless the inspector sees a situation that could jeopardize the life and safety of the occupants.

When it comes to code compliance, it is important to be aware that building codes are updated and revised on a regular basis. If your home is not up to date, do not panic.

Inspectors are not police that travel around town making sure residents bring their houses up to code. But remember, building codes exist to ensure the health and safety of the occupants, so a compliant house is a safe house. Furthermore, if you plan on selling your home, a buyer or lender may want an inspection before the sale is final. Any code violations will likely have to be corrected at that time. It would be better to deal with those issues before selling your home.

Get in the know about plugging in your car

By CCHRC Staff home life.

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Q: Is there anything I need to be cautious about when plugging in my automobile?Q: I’ve seen that there are now roof shingles that are solar panels.While a wide range of solar technologies work in Alaska and other cold climates, photovoltaic roof shingles are still too new and untested for cold regions. The basic concept of solar shingles is excellent because the space is usually wasted and basic support structure is already in place. But remember, things perform differently in our extreme climate. If the shingles are glued on, you have to check how that glue performs in cold temperatures. When it comes to solar technology, there are some general rules to be aware of. Anything that applies to solar means you have to have a good exposure to the sun, preferable facing south.Q: What is a heat recovery ventilator and what does it do?

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.

How to cope with outside insulation

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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 some of the risks with adding insulation to the outside of my home?

It is a complex issue, and what works in one part of the state may not necessarily work in another. The key to successful exterior insulation is to keep moisture from entering the wall from the inside and from the outside. If you cannot ensure this will not happen, then you are insulating at your own risk. If too much moisture moves into your walls or ceiling, then you could end up with mold and rot.

For years, people in Fairbanks and other parts of the state have been applying various amounts of foam insulation to the exterior of their houses. However, this method can also contribute to moisture problems if not done correctly. These problems can originate from inside or outside the house.

In local building code, cold climate construction requires a vapor retarder, placed near the interior wall surface. Most times this consists of a well-sealed layer of polyethylene under the sheetrock.

This barrier membrane is designed to prevent indoor moisture from getting inside walls where it can condense. When you have heat and humidity inside, and a leaky vapor barrier, moisture may get inside a wall. If there are not enough outside layers of foam insulation, this moisture will cool, condense and begin causing problems. Having the proper ratio of insulation on the outside of the wall to insulation on the inside of the wall will help solve this problem.

Also, if you have a good existing interior vapor retarder and add exterior foam, you are creating, what many call, a “double vapor barrier,” as the foam is also relatively impermeable. Should enough moisture find its way into a wall under these conditions, it may have a difficult time drying out.

In some environments, there is the possibility that rain water can work its way into the wall, especially in combination with wind. To minimize these problems, your home may benefit from large overhangs, gutters and proper drainage. Another option is a good draining type of house wrap installed in combination with adhesive or metal flashings, which are applied before putting on the foam. These steps will ensure that if any water gets behind the foam, it will drain down into the ground rather than soak into your framing.

If you put exterior insulation on your house, it will become much tighter. As a result, your indoor humidity levels may increase and the house may no longer receive enough fresh air, making it necessary to better ventilate your home.

An early indicator of elevated indoor humidity levels are your windows. If you are seeing a lot of condensation, especially on a good quality doublepane or triple-pane, that is a good reason to look for a cause.

Q: Are electric stoves more energy efficient than propane ranges?

Strictly, electric energy is very efficient in a range, but it depends on what the cost of propane is, and what the cost of power is in relation. You would have to figure out how much energy, in BTUs, you are getting out of your propane and what you are paying for your kilowatt hours, and compare the two.

Windows offer more than a view, but you have to know what you’re installing

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 windows are preferred for a passive solar home, double- or triple-pane? With or without coatings? Which coatings? What type of glass? Assuming standard building insulation, what is the sweet spot for percentage of glass area?

A: The idea for a passive solar home is a good one, but offers some significant challenges in our climate.

Based on a 1970’s study by University of Alaska researchers, in Fairbanks, for every month of the year besides December, a net energy gain with south-facing windows is possible, but only when the sun is out.

Given that our winters are very cold and have much longer periods of darkness, the heat losses through windows during the dark periods are much greater than the gains we make when the sun is shining. The solution here is a system of insulated exterior shutters. Then, even here in Fairbanks, you could have a house which benefits from a net solar gain for 11 months.

Unfortunately, a perfect heavily insulated shutter system has yet to be invented, but people have built their own shutter systems in typical Alaska style — anything from putting on a piece of 2-inch blue foam to a raise-able shutter that can be engaged with a hand crank from the inside. Keep in mind that, as with all sources of energy, you will make maximum use of solar gain by having an extremely well-insulated building shell. If you have an underinsulated, leaky house, you won’t get the same results.

In a cold climate, we want a window with a low U-value. The U-value represents the rate of heat transfer through the glass. The U-value is usually listed on a sticker on the window or is available from the dealer.

Currently, Alaska Housing Finance Corporation requires a “5-Star Plus” home in Fairbanks to have a window with a U-value of 0.25 or lower, which typically means a triple-pane window.

When it comes to glass and coatings, because we are primarily interested in optimum thermal performance, nearly all windows geared toward our climate will have some variation of low emissivity (low-E) coating designed to reflect radiant heat. Low-E glass usually has some type of metallic film bonded to one of the faces.

For a window with good insulating value, we want a coating that allows some of the short wave infrared energy from the sun to enter the house while minimizing how much of the long wave infrared radiation escapes from the heated space through the glass. This is a balancing act that is dependent on the types of coatings used, and which side of the panes of glass they have been placed on. Coating technology is improving steadily and it is worth the time to research the performance for any type of window line you are considering for purchase.

When it comes to finding the sweet spot of how much surface area should be glass, this varies too, depending on what you are trying to achieve.

In order to comply with the Alaska Housing Finance Corporation “5-star Plus” home requirements, the total window surface area should not exceed 15 percent of the above-grade wall area. The Fairbanks City Building Department uses the same standard. If you go over 15 percent, you will have to make up for those energy losses somewhere else. Often this means adding more insulation to another part of the building. The location of the glass also factors in: south facing works best while north facing should be minimized.

There is much more information on the subject than covered here, but an excellent resource is “A Solar Design Manual for Alaska” written by Rich Seifert from the UAF Cooperative Extension Service.

The book is readily available and accessible online.

Also, Seifert usually teaches a class on solar design in the spring, which is highly recommended to anyone interested in the concept.

Several issues contribute to icy vents and that nasty smell

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: My upstairs bathroom roof vent keeps plugging with ice. This causes a sewer smell in the bathroom. I have to go up on the roof and clear the ice about once a week when it gets below zero. I just put a 90-degree pipe on the roof vent but it still plugged up. Any suggestions?

This is one of those problems that plagues many people, especially as it gets colder.

Proper plumbing venting is critical to the operation of the drain system.

The vent allows pressure to equalize in the system by providing a path for air to be drawn in when wastewater is being sent down the drains.

It also allows the septic system to vent outdoors, rather than into the house — this is the problem you have, and it often becomes more pronounced in winter.

As hot air rises and escapes, or if fans are exhausting air, the replacement air has to come from somewhere. If the vent is plugged, replacement air can sometimes be drawn into the house from the septic system. Usually this happens when a trap is allowed to run dry. If you haven’t used a sink, a shower or a garage drain in a while, the water in the trap can dry out.

This will open up a path for sewer gases to enter the house. The other place it can occasionally happen is with your heat recovery ventilator.

Your HRV system drain may be tied into your plumbing system and have its own separate trap, which is an easy place to overlook, especially if it is in the crawlspace.

Often a roof vent is sized too small, especially in older homes. As a general rule, the size of the roof vent should be the size of the main sewer vent, usually 3 inches. There are many exceptions to this rule, however a 3-inch vent is going to be less likely to freeze up than a smaller vent. In some cases it may be necessary to upgrade to an even larger 4-inch vent, depending on the number of fixtures (such as toilets, sinks and so forth) that are part of the line.

How far the vent travels is something to consider. You may also want to inspect the attic to see how much insulation is around the pipes. If a lot of piping is exposed, it can contribute to freezing, as the outgoing air is going to be more likely to condense and freeze in the pipe.

So to summarize the solutions: Make sure the traps have water in them, insulate the pipes in the attic well and make sure the main vent pipe is large enough in diameter.

Q: I recently upgraded the outside venting range hood in my kitchen. I am wondering if you have any suggestions on how to minimize the amount of cold air that comes in through the vent?

You will likely need some kind of back draft damper to keep the air from being drawn in. Local sheet metal shops carry inline back draft dampers.

They are made to fit snugly inside your pipe with compressible foam around the edges. They have sensitive spring-loaded “butterfly” flaps that open under pressure when the fan turns on.

You will want to install the damper where you can get to it in the future, usually from the outside.

Be sure to put it far enough into the pipe from the outside wall that it is in heated space so that it can’t freeze when moist air hits it. Inline dampers are also good for bathroom fan vent pipes. You never want to use them for dryers though, as they can obstruct the duct, which will collect lint and cause other problems.

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.

Frosty rooftop vents might mean trouble in the attic

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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 have a cold roof. The other day I noticed frost on the vents that are high up on the end walls of my house.

What should I do?

Frost on roof vents of a cold roof indicate you might have air leakage and moisture coming from somewhere inside the house, more than likely through the ceiling. So you have warm air getting into the attic, then out through the vents where it condenses and forms hoarfrost. There are a lot of places this leaking can occur. You could have a chimney or plumbing penetrations going through the ceiling that aren’t sealed properly, poorly sealed can lights, holes in your vapor barrier, or bathroom vents and fans that are broken or not properly connected to the outside.

When it warms up, crawl up into the attic and take a look. If there is so much frost that it is building up on the outside, then there could be some moisture damage inside.

Q: Are there any cautions for replacing windows in the winter?

Flanged windows, especially vinyl ones, get brittle in the extreme cold, so handling them takes a bit more care. Also, expanding spray foam, used to seal the gaps between the window and the framing, doesn’t cure well in low temperatures. The can instructions are pretty specific in this regard, and if you install a foam backer rod into the gap first, which stops the airflow from the outside, then you can spray the foam and it should work.

Q: What are some general rules on when to plug in your automobile?

The rule of thumb that the Alaska Department of Environmental Conservations provides is to plug in for at least a couple hours when it’s 20°F or colder.

I think most of us have realized that if it’s 20°F, you can get by plugging in at a lesser amount and if it’s quite a bit colder you need to plug in longer. If you find you need to leave your car plugged in substantially longer before it starts smoothly, then you car may need some maintenance.

Q: I hear the word “retrofit” being used a lot in talks about fixing up an old house.

What’s the difference between retrofitting and renovating?

Renovating simply means restoring something, making it look new again, or repairing it.

Retrofitting is modifying something old with new technology. In a home, upgrading an older energy system, using a new technique to insulate walls or replacing outof- date windows with new ones are examples of retrofitting.

A heat pump, for what it’s worth

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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.

Be wary when burning coal in a wood stove

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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.

Q: I have a wood stove. Can I burn coal in it, too?

A: Unless a wood stove has been specifically designed to burn coal, too, I would not burn coal in it. For starters, coal has the ability to burn much, much hotter than wood, so it can damage the stove or heat it up so much that it can be a fire hazard to nearby objects.

Also, burning coal in a stove that isn’t airtight or specifically designed for coal can be dangerous because there is no way to shut down the air supply if the fire gets too hot. Add that to the fact that a coal fire takes a lot longer to go out, and you’re asking for trouble.

Q: What is a low e-coating?

A: The low e-coating is a metallic finish on one side of a window pane.

This finish will reflect radiant heat energy.

Radiant heat is heat that passes through electromagnetic waves, like sunlight.

If you have a multiple pane window with multiple coatings, the coating on the outside of the glass will reflect summer heat away from the building to keep it cool, and the coating on the inside of the glass will reflect indoor heat back into the house to keep it warm in the winter.

In Alaska, we typically favor coatings that will reflect heat inside while also choosing a pane that has a high solar heat gain coefficient. That means a window that allows more heat to pass through into the house, rather than reflect it.

Q: Is it worth the energy savings to put my computer to sleep, or should I shut it off every time I’m not using it?

A: That depends on how frequently you use your computer. If you go back and forth to your computer with hours in between, then putting it to sleep is more beneficial.

However, if you only use your computer once per day, such as when you’re at work or when you’re at home in the evening, then turning your computer off is more energy efficient.

Remember, keeping your computer on all day, even in sleep or standby mode, uses power that you have to pay for.

Remember that computers, like cars and people, need a break from time to time. Turning your computer off will give it a rest, and it will function better in the long run.

Alaska HomeWise articles promote awareness of homerelated issues. If you have a question, e-mail the Cold Climate Housing Research Center at akhomewise@cchrc.org.