Insulation

Notes on Insulation in case we come back to the topic in class:

Quotes are directly from websites not my own work, they are just research notes I copied and pasted to use in class. I used: http://www.ornl.gov/sci/roofs+walls/insulation/ins_01.html

• The effectiveness of insulation is rated by an R-value. The higher the R-value, the greater the material's ability to insulate. Each inch of fiberglass blanket insulation, for example, provides an R-value of about 3.27.
• *Start with the attic. Heat rises; make every effort to keep it from leaving when it does. By bringing a minimally insulated attic up to proper insulation levels, you may be able to save up to 30 percent on your heating bill.
• Insulating crawl spaces can trim from 5% to 15% off heating costs
• If you go to the trouble of insulating, it's also smart to make sure that doors and windows are properly weather strippedto cut down on air infiltration and heat loss.
• Heating and cooling account for 50 to 70% of the energy used in the average American home. Inadequate insulation and air leakage are leading causes of energy waste in most homes. Insulation:saves money and our nation's limited energy resourcesmakes your house more comfortable by helping to maintain a uniform temperature throughout the house, andmakes walls, ceilings, and floors warmer in the winter and cooler in the summer.
• Batts, blankets, loose fill, and low-density foams all work by limiting air movement. (These products may be more familiarly called fiberglass, cellulose, polyicynene, and expanded polystyrene.)
• The still air is an effective insulator because it eliminates convection and has low conduction. Some foams, such as polyisocyanurate, polyurethane, and extruded polystyrene, are filled with special gases that provide additional resistance to heat flow.Reflective insulation works by reducing the amount of energy that travels in the form of radiation.
• The different forms of insulation can be used together.
• Rigid insulation is made from fibrous materials or plastic foams and is produced in board-like forms and molded pipe coverings. These provide full coverage with few heat loss paths and are often able to provide a greater R-value where space is limited.
• Reflective insulation is most effective in reducing downward heat flow.
• Fiberglass. Among its benefits, it doesn't burn or shrink, bugs don't like it, and it's made from silica sand, a terrifically abundant resource. However, with potential health risks such as lung damage and cancer warnings, some forms and brands of fiberglass are safer than others, so do your research and ask questions to find the best solution for your home.
• Cellulose. Economical, readily available and better for the environment than fiberglass, cellulose is composed of recycled newspaper and, occasionally, small quantities of shredded cardboard. It carries less health risk than fiberglass, but can condense as it settles and take on moisture, potentially molding if it stays wet.
• Rigid Foam (Foam Board). Mostly made from polymers, water-resistant rigid foam has almost double the R-value (heat flow resistance) of cellulose or fiberglass insulation. Rigid foam is divided into three types: polyisocyanurate (polyiso), expanded polystyrene (EPS) and extruded polystyrene (XPS), each varying in cost, R-value and environmental friendliness.
  
• The following are suggestions of what insulation is best for the specific areas in your home:
• For loft or roof insulation use: Mineral wool quilt, Blown mineral wool, or Blown cellulose fiber.
• For duct or pipe insulation use: Mineral wool mat, Pre-formed split foam insulation, Foil-faced fiberglass insulation, Vinyl-faced insulation, or Ridged foam insulation
• For wall insulation use: Blown-in cellulose, or Fiberglass (batt and roll) insulation
• There are several good alternatives to fiberglass insulation if you want a "green" product to insulate the addition.
• Insulation made from recycled denim is treated with a fire retardant. It's not made of used fabric but scraps from the manufacturing process. In general, growing cotton is tough on the environment because of the heavy use of pesticides, so this may not be the best option, although it's a good use of otherwise wasted material.
• Wool insulation provides an option that is natural and renewable. Although wool is flame resistant naturally, it is subject to insect damage. So the insulation is usually treated with boron to deter insects. But boron is a naturally occurring element and not known to be carcinogenic.
• Cellulose insulation is probably your best bet. It's made from 80% recycled newspaper, and the chemicals that hold it together do not use formaldehyde. Fire-retardant chemicals are also necessary to make the product safe. R-values of fiberglass, wool cellulose are similar, but can vary significantly based on a number of factors. Cellulose insulation is more affordable than wool insulation, too.
• Don't overlook Structural Insulated Panels (SIPs) as an option for building the new addition. SIPs are basically slabs of polystyrene sandwiched between two sheets of oriented strand board (OSB). Because the polystyrene allows very little air to pass through the walls, they produce a super-insulated structure.