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.

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.