This is the sentence:
The enormous room on the ground floor faced towards the north. Cold for all the summer beyond the panes, for all the tropical heat of the room itself, a harsh thin light glared through the windows, hungrily seeking some draped lay figure, some pallid shape of academic goose-flesh, but finding only the glass and nickel and bleakly shining porcelain of a laboratory.
Well, I highly think that for all in that context is an expression, I'm not sure because I couldn't understand the meaning of the sentence.
Could you help please ?