Relative differences in volumes of dust above different temperatures. The volume difference between the single star temperature volume, V ₁, and binary star temperature volume, V ₂, is shown, normalized to V ₁, i.e. – 0.2 means that the total temperature volume is 20% lower if there are two stars compared to one. The envelope mass range is 0.7–24 M_⊙, consistent with the dense core mass range observed in Alves et al. (2007). The relevant mass range for IRAS 16293 is 2.4–4.8 M_⊙, (our IRAS 16293 envelope model has a mass of ~4 M_⊙). There is a clear tendency for a single star to result in more dust heated above ~ 50 K.