Mo Hosni at Kansas State has done a bunch of work on office equipment. I don't know of any studies on lab equipment, it being less common and more specialized. However, the following may give you some insight or leads.
Wilkins, C.K. and Hosni, M.H.. 2000. Heat Gain
From Office Equipment.? ASHRAE Journal, June 2000.
Hosni, M.H., B.W. Jones, H. Xu. 1999. ?Measurement
of heat gain and radiant/convective
split from equipment in buildings.? Final Report
for ASHRAE Research Project 1055-RP,
Institute for Environmental Research, Kansas
State University, March.
Wilkins, C.K. and N. McGaffin. 1994. ?Measuring
computer equipment loads in office
buildings.? ASHRAE Journal, 36(8):21?24.
Komor, P. 1997. ?Space cooling demands
from office plug loads.? ASHRAE Journal,
39(12):41?44.