Hi Francis, here's the nickel tour on heating and ventilating.
As you guessed the selection of how to heat a compartment depended on economy and prestige.
Exposed Steam Radiators: In ordinary store and work rooms that needed to be heated (especially in remote parts of the ship like the water tank rooms) ordinary domestic steam radiators were used.
Hot Air Tanks: In second and third class accommodation, the radiators were placed in air tight drums called "hot air tanks" and a fan blew fresh air over them to warm it up. This comparatively hot air was taken by duct work to the various cabins and public rooms and discharged through louvers.
The advantages here are that the floor space for radiators is eliminated, you get a fairly uniform temperature throughout the ship and "forgotten" radiators don't run the temperature of a room up to 80 or 90 degrees. The bad news is there is no flexibility. The temperature is the temperature, you can only lower it by shutting off the louver (if you can) and wait for the room to cool off. But when you shut the louver off you also stop the supply of fresh air. So in First Class they a composite system of heat regulation.
Warm Air Tanks: These are exactly like the Hot Air Tanks used in 2nd and 3rd with one exception ... they put out air at a lower temperature, about 65 degrees in a typical British ship for the period. This air is distributed throughout the ship and forms the "base" temperature in first class.
There was a large percentage of Americans traveling in first class and while 65 degrees is very comfortable to someone from England, it is absolutely freezing for a Texan, which leads us to "Supplementary heating."
Concealed Steam Radiators: If you look closely at the baseboards of the first class public rooms (especially the gymnasium under the glass signs inboard) you will see that the baseboards are metal with slots cut in them. If passengers were complaining that the Lounge or Smoking Room were too cold, stewards could turn the steam on in these "hidden radiators" and spike the temperature that way.
Supplementary Electrical Heating: The Titanic was supplied with over 500 electric heaters. In the first class baths, private lavatories (750 watts). and first class staterooms (generally 1000 watts), a portable electric heater provided a further boost in the room. Since bathroom and cabin heaters must be portable and throw heat quickly, these electric units were selected as a matter of necessity.
Space Heaters: The last set of electric radiators, the big 3500 and 6000 watt units in the first class entrances, fall into a category of their own. For reasons that are not clear, White Star chose not to have any warm air ducts or baseboard radiators in the stairway foyers, and so the electric units represent the sole source of heat for the entrances.
Had White Star used the warm air and concealed steam radiator system in these areas, it could have done so for virtually no expense of installation and no little operational expense. Instead, White Star decided to install the expensive to purchase operate electrical heaters.
At this point in time, we will never know the logic behind it, but it seams reasonable that it was done simply to impress the
first class passengers with the modernity of a ship heated by clean, futuristic electricity in a world still largely warmed by sooty, old-fashioned coal. I don't think it was an accident that they pretty much only appear in an area that every first class passenger will see and yet, because nobody really spends too much time in a stairway foyer, their uneven heating might go unnoticed.
Bill Sauder
