... .5kw,8.5kw,12kw, 18kw, 21kw, 25kw, heat exchanger titanium in PVC 5/8INCH water exchanger unitAXHE-heating capacity:6.5kw,8.5kw,12kw ... , Axen not only provide the titanium heat exchanger but also supply the products like coaxial heat exchanger, shell and tube heat exchanger, etc. High efficient air to water heat exchanger unit