i have had the same problem once and i work with 'è ambient temperature and all ashrae and other reference state is R value and no mention of thickness
so u can check on www.enginneringtoolbox.com for related insulation thickness for variuos types and application
and u should also check the...
try the folowing web site it has some useful inforemation for heat estimation http://www.engineeringtoolbox.com
but load express the load calculation software for trane gives a 350Watt/computer and accerories such as screen ups printer etc.. whihc usally is good enough.