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Station 4 ?? Temperatures and Moisture. Moisture Meters Pin Contact Data Loggers Spot Temperature Meter Thermal Imager Cautions and Safety. Measure Moisture. Moisture Meters. Contact Type non-destructive reads ~ 3” through materials settings for different materials.
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Station 4 ?? Temperatures and Moisture Moisture Meters Pin Contact Data Loggers Spot Temperature Meter Thermal Imager Cautions and Safety
Moisture Meters Contact Type non-destructive reads ~ 3” through materials settings for different materials Pin-Type makes pin holes extension pins available
Preventing Mold Growth Control the Moisture Keep relative humidity in 30–50% range Keep surfaces warm No leaks inside No leaks from the outside Block entry of moist air Control wicking
Control Interior Moisture Contain moisture at the source Remove moisture with exhaust fans Ventilate: Exchange damp indoor air with dryer outside air De-humidification may be necessary
Relative Humidity Saturation of the air … at a given temperature Water holding capacity (%) of the air 50% RH means the air is 1/2 full 90% RH means the air can only hold 10% more water vapor (90% full)
FACT: Warm air can hold more moisture than Cold air Relative Humidity Temperature
Raise the temperature . . . Relative Humidity Decreases Relative Humidity Temperature
Relative Humidity Temperature
Cool closet = higher relative humidity
Dew Point: Temperature at which air becomes completely saturated (100% RH)
“Wet Air” “Dry Air” Different Relative Humidity of the “Air Film”
Mold and Moisture Materials only need to be at 85% to 90% relative humidity to support mold growth
Mirror reached dew point in Spokane on a hot summer day
Mirror temperature changed little, but moisture in the air changed (high RH%)
Preventing Mold Growth Control the Moisture Keep relative humidity in the 30 to 50% range Keep surfaces warm
Important to understandcondensationDew Point Calculatordpcalc.org http://www.dpcalc.org/
?? 30% Surfaces at ??0 F will be damp
30% Surfaces at 370 F will be damp
?? 30% Surfaces at ?? 0 F will be damp
30% Surfaces at 460 F will be damp
?? 45% Surfaces at ?? 0 F will be damp
45% Surfaces at 500 F will be damp
?? Surfaces at ?? 0 F will be damp
Cordless Temperature and Relative Humidity Logger
Moisture Generation Rate Moisture Removal Rate Aim for 30% to 50 % RH
Moisture Dynamics Relative Humidity: • Saturation of the air at a given temperature . . . • % of its water holding capacity 50% RH = the air is 1/2 full 90% RH = the air can only hold 10% more water vapor
RELATIVE HUMIDITY FACT: Warm AirCan Hold More Moisture ThanCold Air Temperature Relative Humidity
RELATIVE HUMIDITY Raise the air temperature and lower the relative humidity TEMP. R.H.
RELATIVE HUMIDITY Lower the air temperature increases the relative humidity TEMP.R.H.
Moisture Dynamics Dew Point: Temperature at which air becomes completely saturated = 100% Relative Humidity 100% full at this temperature
a/c duct, cold pipes, etc. COLD OUTSIDE Areas of High RH Buildings have Micro-climates
Dry Bulb = 72 0F Wet Bulb = 60 0F Relative Humidity = 50 % Dew Point Temp =52 0F
40 0F 70 0F 100 % R H ??? 100 % RH
Outdoors Indoors 40 0F 70 0F 100 % RH 35 % R H
a/c duct, cold pipes, etc. COLD OUTSIDE Areas of High RH Buildings have Micro-climates
Moisture + Asbestos = Double Trouble
single pane glass indicates high moisture levels
Ventilation Exhaust Fans Breathing Shower Repair Plants Cooking Cleaning Laundry Leaks Dishes, etc.
1,500 ft sq house 700 F indoor temp 85 % outdoor RH Ventilation (AC/h)VS Indoor Relative Humidity (%) .35 AC/h 300F outside temp typical moisture load Indoor Relative Humidity (%) Ventilation: Air Chances per Hour (AC/h) based on G. Tsongas
1,500 ft sq house 700 F indoor temp 85 % outdoor RH Ventilation (AC/h)VS Indoor Relative Humidity (%) .35 AC/h 500 F outside temp typical moisture load Indoor Relative Humidity (%) Ventilation: Air Chances per Hour (AC/h) based on G. Tsongas