Base paper for total heat exchanger element

摘要

The object of the present invention is to provide a base sheet for a total heat exchanger element such that the base sheet has a high moisture permeability and an appropriate rate of moisture absorption as well as excels in flame resistance and gas barrier properties while its basis weight is low. A base sheet for a total heat exchanger element comprising calcium chloride in a paper base material, characterized in that the paper base material comprises pulp with a freeness of from 200 to 600 ml as measured in accordance with JIS P 8121 except that a pulp collection amount is set to 0.3 g/L; the paper base material has a bone-dry basis weight of from 17 g/m2 to less than 23 g/m2; and content of the calcium chloride is from 6 g/m2 to less than 9 g/m2.