Here Comes The Sun

i recall seeing "day and night" water heaters when i was very young. i thought they were so called because they provided hot water day and night, because they burned natural gas to heat the water. i was wrong about the gas part. the name was left over from the day and night solar water heater company.

"In 1909, William J. Bailey patented a solar water heater that revolutionized the business. He separated the solar water heater into two parts: a heating element exposed to the sun and an insulated storage unit tucked away in the house so families could have sun heated water day and night and early the next morning. The heating element consisted of pipes attached to a black-painted metal sheet placed in a glass-covered box. Because the water to be heated passed through narrow pipes rather than sat in a large tank, Bailey reduced the volume of water exposed to the sun at any single moment and therefore, the water heated up faster. Providing hotter water for longer periods put Bailey's solar hot water heater, called the Day and Night, at a great advantage over the competition. Soon the Climax went out of business. From 1909, when Bailey started up his business, through 1918, his company had sold more than 4,000 Day and Night Solar Hot Water Heaters."

from "A Golden Thread" by Ken Butti and John Perlin

this water heating system arranged the separate heat collector below the storage tank. as the water in the collector warmed it wanted to rise. a pipe from the top of the collector connected to the top of the tank and another pipe ran from the bottom of the tank to the bottom of the collector. so the water could follow its inclination and circulate, creating a passive system for heating water and storing it in an insulated tank using a thermosiphon. at night when the collector radiated heat to the night sky the water would cool but not circulate as it was already at the low point of the system. thus the water heated during the day would remain warm in the insulated tank.

the demise of solar water heating in california came when cheap natural gas was delivered by pipe to most houses. the eventual plumbing failure of early materials also made replacement of the collectors and tanks more expensive than replacing the system with a single gas-fired tank.

technology has given us much better materials to work with, but a thermosiphon still works just the same. as the cost of both gas, either propane or natural, and electricity rises the various uses of solar heat will once again become economically attractive.

"A Golden thread" also tells of this solar powered water pump built in 1910. and here is a link to a group using old technology with new materials in less-developed parts of the world. they even have plans for a solar powered refrigerator!

we are investigating the options for a solar water heating collector for our own use. to avoid the problems of freezing, we will shut down and drain the system in the winter. six to eight months of solar assisted water heating is better than nothing. we will probably use an electric water heater tank to store the heated water. the tank will be in the insulated garage. in the summer the sun will preheat water for the propane water heater. in the winter we will turn on the electricity for preheating, as it is cheaper than propane. watch this space for further news.