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Difference between revisions of "House insulation"

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* Federal Minimum Property Standards could be reached nationwide is everyone saved atleast 15% of current heating demand.
 
* Federal Minimum Property Standards could be reached nationwide is everyone saved atleast 15% of current heating demand.
 
--The minimum insulation recommendations are currently
 
--The minimum insulation recommendations are currently
    *Celings have to now have a [R value] of 38, not the previous 19
+
*Celings have to now have a [R value] of 38, not the previous 19
    *Wall's [R Value] should be 19, instead of the previous 11.
+
*Wall's [R Value] should be 19, instead of the previous 11.
    *Floors should have a 11 [R-value], instead of the previous 22.
+
*Floors should have a 11 [R-value], instead of the previous 22.
  
 
Thermal Resistance = R value
 
Thermal Resistance = R value
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Example in Wall Values
 
Example in Wall Values
--Combination of various materials = greater R value = greater insulation and > energy (heat/cooling) loss
+
-Combination of various materials = greater R value = greater insulation and > energy (heat/cooling) loss
****R for a typical wall has siding, plywood, fiberglass insulation, and plasterboard
+
*R for a typical wall has siding, plywood, fiberglass insulation, and plasterboard
  
 
Things that Affect R value
 
Things that Affect R value

Revision as of 16:12, 7 December 2007

Insulating Your House

ABSTRACT

The basic idea is to use the appropriate insulation within your home to save on heating and cooling costs. There are easy fixes and many new technology in insulation that will prevent thermal loss year round. The expenses might seem high but will be able to pay for themselves in years and create a more energy efficient environment. This article will discuss the different options and procedures available.

Physics Principles of Insulation

Building Materials

Insulators

  • Choice ones that "retard the flow of heat from one object to another"
  • High "resistance to heat transfer
  • Porous Materials are Great Insulators

- This is due to the air in the pores acts as a "Good insulator"

  • Choose darker objects = better emitter and absorber
  • Darker objects > absorber/emmitter than white
  • Thermos = bottle inside a bottle

- Device to reduce heat transfer - 2 bottles seperated by a vaccum = > heat transfer from to inside chamber

Types of Insulation

4 BASIC TYPES OF INSULATION

Loose-fill Insulation

  • Materials included in:
    • loose fibers or fiber pellets
    • Made of Cellulose fibers chemically treated to be moisture and fire resistent
    • Fiberglass and Rock Wool = [Blow-in Blanket System] (BIBS)
    • cost more then batt insulation
  • Benefits/Positives
    • Fills small cracks/crevices easier
    • Reduces air Leakage better
    • Better sound reducer (then natt insulation)
    • R-3 to R-4 value per inch
    • Cellulose fiber > (by 30%) then loose-fill rock wool

Batt and Blanket Insulation

  • Materials Include:
    • Made of Mineral Fibers (fiberglass or rock wool)
  • Benefits/Positives
    • Least expensive wall insulation material
    • Best for Standard joist/rafters/studs
    • Build in radiant barrier backing
    • Come in long rolls that can be cut to desired length
    • R-value of Approximately R-3 per inch thickness

Rigid Board Insulation

  • Materials Include:
    • Made from fiberglass, polystyrene, or polyurethane
  • Benefits/Positives
    • Come in variety of thicknesses
    • R-value is the HIGHEST = R-4 to R-8 per inch
  • Uses
    • Reproofing work on flat roofs
    • Basement Walls
    • Perimeter insulation at concrete slab edges
    • Cathedral Ceilings
    • Must be covered with 1/2 inch gypsum board in used inside
    • Must be covered with Weather-proof facing if used exteriorly
  • Uses
    • Insulate below floors, above ceilings, and within walls

Spray Foam Insulation

  • Materials include:
    • Two-part liquid containing polymer and foam agent
  • Uses
    • Sprayed on Wall, ceiling, and floor cavities
    • Expands to sold cellular plastic with many air cavities
    • Good for irregular shaped areas and around abstructions
  • Negatives
    • Require specific machinery to spray/mix

IF YOU NEED HELP DETERMINING THE TYPE OF INSULATION, CONSULT A CONTRACTOR OR TRY THIS SITE <http://www.ornl.gov/sci/roofs+walls/insulation/ins_08.html>

Proper Procedures

Materials

Estimated Costs (Energy and It's Uses in the Environment)

  • Increased Insulation = save as much as 50% on heating/cooling bills
  • Federal Minimum Property Standards could be reached nationwide is everyone saved atleast 15% of current heating demand.

--The minimum insulation recommendations are currently

  • Celings have to now have a [R value] of 38, not the previous 19
  • Wall's [R Value] should be 19, instead of the previous 11.
  • Floors should have a 11 [R-value], instead of the previous 22.

Thermal Resistance = R value

    • Given by thickness/material's thermal conductivity (delta/k).
      • Higher R-value = better insulating properties

R-Values Per Inch For Common Insulating Materials* ---For a broader table please follow this external link <http://www.coloradoenergy.org/procorner/stuff/r-values.htm>

Material Thickness R-Value
Hard wood 1" 0.91
Plywood 1/2" 0.62
Wood siding 1/2" 0.81
Asphalt roofing Shingle .44
Fiberglass insulation 3 1/2" 10.9
Fiberglass insulation 6" 19.0

Example in Wall Values -Combination of various materials = greater R value = greater insulation and > energy (heat/cooling) loss

  • R for a typical wall has siding, plywood, fiberglass insulation, and plasterboard

Things that Affect R value

  • Location

-"Convective resistance depends strongly on the velocity of the air moving along the surface." All previous values are for areas with 10mph winds.

  • "If the wind velocity increases to 15mph, the R-Value of the air film is decreased by 50%.

- ANSWERS TO SOLVING SUCH PROBLEMS

  • Plant trees and schrubs near house to reduce wind effects.

Common Mishapps When Insulating Your Own Home

  • AIR LEAKS

- Unsealed gaps around: Joists, sills, windows, no weatherstipping around doors, Exterior Vents (Water Connections, Kitchen/Bathroom Vents, Dampers/vents)

- Cracks in Foundation/Walls/Chimneys

- Poorly fitted Air Barriers in Walls: Attach Hatches and Wall outlets

References

-Hinrichs and Kleinbach. "Energy It's Use and the Environment" 3rd Edition. Thomson Learning, New York, NY 2002.

- Almost any HOW TO BOOK. I love the Black and Decker Complete Photo Guide to Home Repair. It contains a basic backround and visual step by step procedure.

- "Energy Efficient Rehab Advisor" <http://rehabadvisor.pathnet.org/sp.asp?id=10783>

Helpinghandsjmp2.jpg This page is part of a project for PH261, a Clarion University class on the physics of energy and the environment. Please do not edit this page before Dec. 15, 2007 unless you are in that class, but feel free to make comments using the discussion tab.