When a tree grows it absorbs carbon dioxide, nutrients from the soil, and heat from the sun. Wood fiber and oxygen are produced. As wood is burned, heat is released, carbon dioxide is produced and nutrients are returned to the soil as ash.
If the wood is left to rot on the forest floor or buried in a landfill it still releases the same carbon dioxide, slowly bleeds out the heat (à la your compost pile), and returns the nutrients whence they came.
In other words, that piece of firewood is a portable package of solar energy and a collection of unwanted atmospheric gas.
Carbon dioxide is a naturally occurring greenhouse gas like nitrous oxide, methane, water vapor and ozone. These all absorb heat in the atmosphere.
So by extension of the logic, continuing deforestation creates more greenhouse gases by returning more carbon dioxide to the atmosphere instead of leaving it stored in trees.
Q: I have fire sprinkler heads in my condo with little exposed red-mercury glass vials. The concern is that, if I accidentally smack it, I am going to get wet, and so is the neighbor beneath me. We in the complex have no way of turning the system off, as the fire-sprinkler room is locked. Only the fire department has a key, I am told. I have thought about a protective cage around the heads, but wonder if this would lessen their effectiveness.
A: Cages should be in place over heads that are in a garage, closet or another location vulnerable to physical damage. The cages won't affect the ability to perform as needed. Another alternative is to install flush heads. These aren't visually intrusive like the type that stick down below the ceiling line. They are not cheap, and will need to be installed by a fire-suppression contractor.
Q: Are there any long-term negative health or building effects from using polyurethane insulation in my new house? This spray-on foam is more expensive than glass fiber, but it has a lot of advantages that I appreciate. Better air sealing, no vapor-barrier requirement, no moisture absorption, etc. But I don't see very many houses with it. What do you know about it?
A: This type of material is still suffering from bad press. Urea formaldehyde insulation was also sprayed on, and the out-gassing created paranoia — kind of like asbestos and mold today. But the good news is today's foam insulation does not outgas after it has cured. The denser installations add a bit of structural strength, too. One of the better known purveyors is Icynene, which has several local dealers. www.icynene.com
Darrell Hay answers readers' questions. Call 206-464-8514 to record your question |
