Nathan Yost, MD
Columbus Green Building Forum
12/5/2009

  • Any one change can have other effects.
  • The rest of the world does not build wood house , except Canada, Norwegian.
  • Houses where trying to do things better is where problem occur.
  • What a house is now suppose to do NOW.
    • Stay within a narrow temperature and humidity range
      • Creating a greater difference in temperature for outside and inside.
  • Breathing of house
    • Buildings do not need to breath, they need to be ventilated.
  • How material Dry?
  • Due point is important, not relative humidity.
    • Important to if condensation with occur.
  • Mold
    • Cold corners of closet
      • No venation, no heat, wood corners with no insulation
  • Sheathing
    • Moisture levels vary greatly depending on material
    • OSB worse, Paper face Gypsum board worser.
  • Vapor retarder (Permeability)
    • I perm or less by code
    • Craft face insulation works
    • Poly sheets are worse
  • Air Leakage
    • More important than permeability.
  • Brick and stucco has possibility of vapor entering house.
  • In house humidifiers that are not adjusted per the temperature outside can cause vapor to transfer through the wall to the outside.
  • Decreased energy flow through walls cause decreased drying.
  • Insulating historic structural brick buildings can cause the slowing of drying of the water  in the brick.
  • Columbus house’s basements are in clay basements: wet walls.

Energy

  • Do not use energy modeling software for existing house is not worth the effort.
  • Use the utilities bills for your house for past 2 years or more.
  • Excel spreadsheets are great for analysis.
  • Breakdown
    • Spaceing heating
    • Space cooling
    • Heating water
    • Lighting and plug load
  • Utility company does not measure on a monthly method.
  • From the analysis you can see where it is more economical to improve the house.
  • Analysis both by cost and amount (gas).
  • Important factors
    • Number of occupants
    • Thermostat setting
  • Tent behavior
    • Sumer big tent – live in all rooms
    • Winter small tent – live in houses center room.
  • As wallet is driving force people improve thermal value and efficiency that allow able to set thermostat at higher temperature. Ends at save cost.
  • 90% efficiency furnaces and boilers are best. Worth replacing 80% efficiency furnace.
  • Windows are poor economic return based on energy, but other reasons.
    • Typical is R1, R3 is better.
  • Blower door test is not needed most times.
    • Locations of holes is more important than the number.
  • When
    • Add exterior insulation when residing.
  • Online program to look at your house http://hesw1.lbl.gove.
  • Newer Instant heat water heaters require about ½ gallon of water flow to heat water.

Do

  • Air sealing big holes.
    • Wiring coming in.
    • Balloon framing openings between floors.
  • Eliminating panned “duct” returns in exterior walls.
  • Adding insulation.
  • Air handler fans – DC commutated motors – expensive
  • Appliances – look at pay back.
  • Replacing windows – typically least pay back.
    • Replacement windows are undersides
    • Not just stuffing fiber glass in crack. Use sealants.
  • Combustion safety
    • Air sealing make sure no internal carbon monoxide trapped in house.
  • Is there are moisture source that leads to the attic?
  • Is there a vapor barrier present in the wall assembly
  • Is there drainage plain behind the siding.
  • Ventilation continuous exhaust fan in bathroom in addition to regular bathroom fan.
  • Radon exhaust at times also reduces humidity in basement.
  • Check attics in the winter in cold climates for moisture.

Products

  • Monitor electrical use: TED

Questions

  • Stucco walls works better with insulated sheathings
  • Building performance Institute
  • Resnet has some people with no practical experience.