Comment My art is prior. (Score 3, Interesting) 160
My first unix box was an Altos. Don't recall exactly when I got it but it finally died in the late '80s.
The thing burned something like a kilowatt. It also had a four-inch muffin fan - blowing outward. While this sucked dust in all the openings, it was convenient for heat scavenging, AND exhaust. The latter was important in my non-air-conditioned college-town house.
I got a couple 4" drier vents, some drier vent hose, and a heat-scavenging diverter valve (which were big that year - for electric driers only!). Took the flapper valve and rain shield off one of the drier vents, yeilding a fitting that I mounted on the pancae fan's four mounting screws. It coupled the airflow nicely into the drier vent hose, which was essentially exactly the diameter of the fan blade shroud. A few 2x4s mad a wooden insert that went into the window in place of the screen unit, with the other vent in the middle of it. Hooked the two together with the hose, with the diverter in the middle of it, and the third hose segment feeding the hot air register.
In the summer the space-heater's-worth of hot air went out the window instead of into the house. In the winter the hot air fed the furnace distributon, providing a base heat supply to the house with the furnace coming on to "top it off" to the desired temperature.