Home Heat and Efficiency: Part IV – heat rises
In 1749, Benjamin Franklin heated a row of ten townhouses in Philadelphia from a single apparatus, replacing ten fires with one. The device was probably adapted from Roman hypocausts, a method of supplying heat to a stone building with a system of flues in the walls that channeled the fire’s exhaust gasses beneath the floor. rochester.edu
In 1810, Daniel Pettibone invented a central furnace using hot air to heat six rooms at Philadelphia's Pennsylvania Hospital. The device called a ‘rarifying air stove� was used to heat the government halls of our nation’s capital for decades until it was replaced by steam heat.
I would love to find a picture of this invention. By definition to rarify means to purify, thin, make less compact, or less dense all of which defines making the air rise, as heated air is lighter, and conditioning of the air.
In theory, it is more efficient and costs less to use one source of fire to heat several rooms than to heat each room with a stove or fireplace.
Experiments in central heating would became more commonplace by the mid-19th century and mass production of these ideas brought the cost down for the masses.
Early furnaces, however, rarely heated all the rooms in a house, so homeowners still used fireplaces, especially in north-facing rooms. Fireplaces had the added advantage of drawing centrally heated air from other rooms. Early American Life (Camp Hill, PA)
Next:
Part V – go with the flow
Previous:
Part III – Beyond the potbelly
Part II – Fireplace
Part I - Fire
About this series: With the onset of cold weather, I started thinking about where my boiler originated from. Heating our living space is a constant evolution of comfort and efficiency. From fire pits to geothermal heat pumps, looking to the past brings solutions for the future.
