Waterbed



A waterbed, water mattress, or flotation mattress is a bed or mattress filled with water. Waterbeds intended for medical therapies appear in various reports through the 19th century. The modern version, invented in San Francisco and patented in 1971, became an extremely popular consumer item in the United States through the 1980s and 90s. Currently they account for less than 5% of new bed sales.

Construction
Waterbeds primarily consist of two types, hard-sided beds and soft-sided beds.

A hard-sided waterbed consists of a water-containing mattress inside a rectangular frame of wood resting on a plywood deck that sits on a platform.

A soft-sided waterbed consists of a water-containing mattress inside of a rectangular frame of sturdy foam, zippered inside a fabric casing, which sits on a platform. It looks like a conventional bed and is designed to fit existing bedroom furniture. The platform usually looks like a conventional foundation or box spring, and sits atop a reinforced metal frame.

Early waterbed mattresses, and many inexpensive modern mattresses, have a single water chamber. When the water mass in these "free flow" mattresses is disturbed, significant wave action can be felt, and they need time to stabilize after a disturbance. Later types employed wave-reducing methods, including fiber batting and interconnected water chambers. More expensive "waveless" modern waterbeds have a mixture of air and water chambers, usually interconnected.



Water beds are normally heated. Temperature is controlled via a thermostat and set to personal preference, but is most commonly average skin temperature, 30 °C or about 86 °F. A typical heating pad consumes 150–400 watts of power. Depending on insulation, bedding, temperature, use, and other factors, electricity usage may vary, significantly.

Waterbeds are usually constructed from soft polyvinyl chloride (PVC) or similar material. They can be repaired with practically any vinyl repair kit.

History in 1800s
A form of waterbed was invented in the early 19th century by the Scottish physician Neil Arnott. Dr. Arnott's Hydrostatic Bed was devised to prevent bedsores in invalids, and comprised a bath of water with a covering of rubber-impregnated canvas, on which lighter bedding was placed. Arnott didn't patent it, permitting anyone to construct a bed to this design.

The use of a waterbed (for the ailing Mrs. Hale) is mentioned in Elizabeth Gaskell's 1855 novel North and South.

In 1871, a waterbed was in use in Elmira, New York, for "invalids". It was briefly mentioned by Mark Twain in his article "A New Beecher Church" which was published in The New York Times on 23 July 1871. Twain wrote: "In the infirmary will be kept one or two water-beds (for invalids whose pains will not allow them to be on a less yielding substance) and half a dozen reclining invalid-chairs on wheels. The water-beds and invalid-chairs at present belonging to the church are always in demand, and never out of service". No further information is available.

Heinlein descriptions
Science fiction writer Robert A. Heinlein described therapeutic waterbeds in his novels Beyond This Horizon (1942), Double Star (1956), and Stranger in a Strange Land (1961). In 1980 Heinlein recalled in Expanded Universe:


 * I designed the waterbed during years as a bed patient in the middle thirties; a pump to control water level, side supports to permit one to float rather than simply lying on a not very soft water filled mattress. Thermostatic control of temperature, safety interfaces to avoid all possibility of electric shock, waterproof box to make a leak no more important than a leaky hot water bottle rather than a domestic disaster, calculation of floor loads (important!), internal rubber mattress and lighting, reading, and eating arrangements—an attempt to design the perfect hospital bed by one who had spent too damn much time in hospital beds.

Heinlein made no attempt to build his invention.

The Hall Waterbed
The modern waterbed was created by Charles Prior Hall in 1968, while he was a design student at San Francisco State University in California. Fellow SFSU students Paul Heckel and Evan Fawkes also contributed to the concept. Hall originally wanted to make an innovative chair. His first prototype was a vinyl bag with 300 pounds (136 kg) of cornstarch, but the result was uncomfortable. He next filled it with Jell-O, which had an "unfortunate tendency to decompose". Ultimately, he abandoned working on a chair, and settled on perfecting a bed.

Hall was granted a patent on his waterbed, which he originally called "the pleasure pit", in 1971. He founded Innerspace Environments, a manufacturing and sales company which became the leading retailer of waterbeds in the United States, with 30 owned-and-operated stores. Hall was unable to defend his patents against multiple competitors and couldn't take full advantage of the waterbed's subsequent popularity. Sales peaked in 1987 at 22% of the domestic mattress industry.

Regarding usage
The waterbed can be useful and comfortable for some and dangerous for others. The main feature of the waterbed found attractive is its form-fitting, pressure-minimizing nature. Not only is this a boon to those seeking mere comfort, but the removal of pressure from the spine can provide relief to those with back pain. In addition, the distribution of weight can prevent bedsores among the paralytic and the comatose. However, the National Institute of Child Health and Human Development warns that the form-fitting nature of the water-bed poses a danger to infants, providing a possibility of asphyxiation.

Regarding non-use
A primary advantage of a waterbed is its easy cleaning. It is impossible for dirt and dead skin particles to penetrate the water mattress, which can then be wiped periodically with a cloth and vinyl cleaner. The cover over the mattress can be regularly washed—thus virtually eliminating house dust mites in the bed. Dust mites can trigger asthma, eczema, and allergies in people sensitive to them.

The practical drawbacks are more numerous. First, since some hard-sided waterbeds are of different sizes than other mattresses, bed sheets are harder to find and come in fewer varieties. Soft-sided mattresses are conventionally sized to avoid this problem. Second, moving a waterbed is a more difficult process than moving a normal bed; the water must be drained and the frame disassembled, then the frame must be reassembled, the mattress refilled with water, and the water heated for a potentially long period to get the new water to the correct temperature. And heating the bed can be costly: a waterbed consumes between 300 and 1500 kW·h/year, depending on the climate, bed size, and other factors. The energy usage can be decreased by about 60% with the use of a soft-sided waterbed. The water itself can pose challenges: occasionally, water mattresses may leak. Plastic liners will reduce damage, but emptying, patching, refilling, and reheating it (and sleeping elsewhere until all this is completed) is certainly an inconvenience.

Contractual inconveniences
There can be contractual inconveniences; many apartment leases and home insurance policies restrict the use of "water-filled furniture" due to concerns about water damage to the dwelling due to accidental leakage as well as the stress on the floor.