Here is a link to PM plumbing and mechanical magazine, it is a free mag if you go online and sign up. lots of useful info tips and the latest equipment, codes and regulations coming to the hydronic market. Its also available online freeview. http://www.pmmag.com/Articles/Column/5694bef6ddfc7010VgnVCM100000f932a8c0____ There is also a section called RHR or radiant heating report that is just that. Archives of past issues available too, pump sizing, cost projections of equipment, efficiency controls, Outdoor reset curves and products, the new pex pipe. Anyways as long as its ok to post here thought I'd pass on the free info.