Visualize EnergyPlus results with Honeybee

Hi all,

Very impressed with the latest Honeybee release. I'm attempting to use Honeybee to visualize surface temperature data from pre-existing EnergyPlus models. I thought I had a handle on this from watching Chris's (very informative) videos, but keep receiving an error.

I've run the EnergyPlus models separately, and outputted the surface data, and surface temperature data in those models. My idea was to use the "import_idf" function to get the honeybee zones, and "read_ep_surface_results" for the temperature data. When connecting these items to the "color_surfaces_by_ep_results", i get the following

error: 1. Solution exception:unsupported operand type(s) for -: 'str' and 'int'

Any advice as to where this error comes from? or if this technique will even accomplish what I hope? 

Thanks,

Stefan