A few nice Water Filtration images I found:
1139 Baker St interior
Image by simonov
The previous tenant was a solar company called DynGlobal. They also had something to do with solar powered water filtration. They sorta trashed the place before they left. Before DynGlobal, Stacoswitch occupied the building for 45 years.
A CGI 3D plan of the building is available here.