Indirect fired equipment is an ideal solution for applications where air recirculation is desired. As no byproducts of combustion enter the space being heated, air can be recirculated through the unit without requiring any fresh outside air. For this specific application the outside/return air proportion is controlled based on building pressure, modulating to achieve a slightly positive building pressure overall.
Titan indirect fired heating equipment can be designed with multiple heat exchangers, offering enhanced turndown potential. This unit featured 10:1 turndown ratio.