Structural Insulated Panels use various thicknesses of styrene foam between two skins of oriented strand board or plywood to create very strong structural walls and ceilings that can span up to 23 feet and have R values significantly higher than stick frames.
That energy efficiency carries a price. The airtight construction requires water vapor be removed from the inside using a dehumidifier that also brings in fresh air. The alternative would be water tight paints (ha) or HDPE visqueen vapor barriers with all the controversy they carry.
I’d like to focus on experiences anyone has had installing dehumidifiers in SIP construction, where intake and outlet were installed on vertical walls, the kilowatt requirements per hour or month, and whether the target 50% relative humidity was reached, and whether the expenditure was dehumidifying was less than the heating and cooling cost savings.
Did a dehumidifier suceed in preventing rot especialy near the peak of the roof?
On the outside, has anyone used furring strips to allow air to circulate between the OSB and the cladding and did this air space prevent rot from developing?