HC Freshwater Desalination Water Conservation OnDemand Hot Water Systems
Although each HC will be sitting on an almost inexhaustible water mine; water for consumption will still be a challenge as these seawaters need to be made fit for consumption.
Throughout the HC, precautions and water economy devices (e.g., automatic faucets, on/off showerhead flow controls, etc) will be used in order to keep potable water waste as close to zero as possible. The maintenance of an HC's easily accessible water distribution system will also be a priority as this can lead to tremendous wastes. (It is estimated that in general, water lost through leakage is 10 to 15 percent of a city's water use. And that the city of Chicago for example loses about 490 million liters (130 million gallons) of water daily through waste.1)
For economical reasons, the default system for providing hot water will be what is known as "On Demand" hot water heaters (aka. "tankless" or "instant" hot water heaters). This system has many advantages over water heaters with storage tanks such as having recyclable parts, a longer use life (15-25 years vs. 10 years), using much less energy (as much as 69% less) as water is only heated when it is needed, etc. (cf. page 1, and page 2). Its main disadvantage of not providing sufficient water in simultaneous use where the applications are using large amounts of hot water can be overcome by either (1) planning uses to prevent simultaneous uses, (2) adding a second units or dedicated units if simultaneous uses are really inevitable. (There will also be solar water collectors installed upon HC houses in order to preheat water for the OnDemand hot water system).
The Following table show the expected typical daily potable water use per HC household including hot water use data:
1 Keinath, Thomas M. "Water." World Book Online Reference Center. 2005. World Book, Inc. 12 Jan. 2005.
May 28, 2008
Desalination Water Conservation OnDemand Hot Water Systems
Water Conservation OnDemand Hot Water Systems