The Shipbuilder special issue on the Olympic and Titanic, first published in 1911, has been reprinted at various times in book form. Not in print right now, but second-hand copies can generally be found from online dealers - try the Amazon marketplace. If it's the electric heaters you're interested in, more or less the same information can be found in this 1911 article from The Electrician (see bottom of page):
First class cabins had electric heat. Most other spaces had more than enough heat due to heat transmitted from machinery spaces through bulkheads, by electric lighting, etc. Mechanical ventilation was provided. A reference is Titanic, The Ship Magnificent, Vol. 1, by Bruce Bevridge.