Patent ID: 8726978

Claim:
A heat exchanger element comprising: partition members made of a material that is liquid absorbing and not flame retardant, which form first gas passages configured to flow a first gas and second gas passages configured to flow a second gas, the partition members operative to partition the first gas passages and the second gas passages; spacing members made of a material that is liquid absorbing and not flame retardant, which form the first gas passages and the second gas passages together with the partition members and that maintain a gap between the partition members; and a water solvent adhesive that adheres the partition members and the spacing members with each other, a water-soluble flame retardant being dissolved into the water-solvent adhesive, the water-soluble flame retardant permeating and diffusing into the partition members and the spacing members from the water solvent adhesive and providing the partition members and the spacing members with flame retardancy at the time of adhesion.