Conjugate Heat Transfer
 

I have a question regarding coupling in conjugate heat transfer in Fluent. In fluent we have the option of loosely coupled conjugate heat transfer. My question is if we solve the model by just ticking the "specify solid time step size". Is it more accurate or we should opt for the option of loosely coupled conjugate heat transfer if we are simulating heat transfer between the fluid flowing in the pipe and the solid domain adjacent to the pipe?