Regenerative heat exchangers with different regenerative cartridges are the objects of the heat research in this article. These regenerative cartridges are made of a different material. They are of a different form and also they have different areas of passage. Fan, with is used in regenerative heat exchangers is the same for both. It has a possibility for reverse operating. During the experimental research the regenerating/accumulating coefficient which shows the termal efficiency of these heat exchangers was measured. Also the conclusions of corresponding fan and regenerative cartridge are given in this article.