Temperature variations of full-size ceiling insulation model and roof insuration model are measured and observed to prevent melting and freezing of snow on the roof during winter. As a result, roof insulation model with ventilated air space is quite effective to prevent the problem caused by snowmelting on the roof since the temperature inside the ventilated air space follow the outside temperature well. On the other hand, ceiling insulation model leaves much room for improvement on ventilaion method in attic space because of the bad followrity of temperature inside the attic space.
