Changes

WaterCapacity

913 bytes added, 16:21, 5 December 2015
m
Calculating Water Capacity
= Water Capacity =
[<B>TO BE UPDATED</B>] [Standard estimates of water consumption for yachtsmen yachters assume a certain austere lifestyle. But everyone’s comfort level is different.
== Design Considerations ==
There are many estimates of water consumption available for yachtsmenyachters. But it is better to start with first principles when designing your system. If your boay is intended as a live-aboard in all seasons, while remaining qualified as a passagemaker, getting the heating, air conditioning and water systems right-sized is critical from a comfort and energy-efficiency aspect.
In the water system, this comes down to how much hot water do we need in a day. We don’t need that much for drinking and cooking. The difference is in life-style usage. Everyone’s comfort level will be different. The criteria for a live-aboard are different from a weekend cruiser or racing yacht. Living aboard, we should always have hot water when we need it; not waste water; and conserve energy.
The literature on water consumption is all over the map. Experienced yachtsmen on cruising sail boats can manage on 1.5 gal of water per day per person, for all needs excluding bathing and dish washing; although 3-6 gal is more common.
Other yachting estimates are as high as 15 gal a day per person. At the other extreme, one 400-passenger cruise ship, the <i>MV Millennium Queen</i> (believed broken up in 2001), budgets budgeted 60 gal per day per passenger, which is close to domestic consumption. Domestic consumption is a benchmark for a live-aboard, but estimates still vary widely.
For a standard office, guidelines are 25 gal/day per person but have been shown to be as low as 6.8 with conservation measures [3]<ref>http://ncprojectgreen.com/</ref>. Of course, office estimates don’t include cooking, showering and washing clothes, etc.
For domestic consumption, [http://www.watertechonline.com/ WaterTech.Online ] also recommends 25 gal/day d per person [4] but [http://www.nrcan.gc.ca/ Natural Resources Canada ] (NRCan) estimates real usage as 88 gal/day [48]d.
NRCan says average daily consumption is 1000 Ll/day d (264 galsgal) for three people with 40% for toilets. This puts Canadians among the thirstiest on the planet. Must be all the Beer! More Beer! My toilet flushes with 1.6 gal so NRCan assumes I hit it 22 times a day, or about every 45 min. Putting aside the toilet jibe, I find 88 gal realistic, as shown later.
Environment Canada estimates the distribution of domestic consumption as shown in Fig[http://www. 11-1ec.Fig 11gc.ca/eau-1 Distribution of domestic water consumption© / Environment Canada http] estimates daily per capita usage as 79 gals. <ref>https://www.ec.gc.ca/water/imagesindicateurs-indicators/manage/effic/a6f7edefault.htmasp?lang=en&n=7E808512-1</ref>
Vendor specifications also indicate that many marine toilets require 3-5 gal per flush, with the most efficient (VacuFlush) requiring only 0.375 10 gal (/0.8 L)39 liter. <ref>http://www.dometic.com/USA/MS-11346-Marine/PG-11395-Toilet-Systems#q2</ref> The more profligate ones can use seawater but VacuFlush requires fresh water [49].
Other sources estimate that domestic hot-water consumption alone runs 20-35 gal/day per person, with a peak demand of 10 gal [?]. To meet such a peak demand, the [[HotWaterHeater|hot water heater ]] must deliver 10 gal/person at any time. Additional capacity is needed for appliances, such as dishwashers.
Other capacity recommendations for hot water tanks range from 7 gal per person [2] to as high as 17 gal.
In tests in my apartment taking showers not baths I the observed a daily consumption of was about 40 gal. Taking a bath (52-in bath) quickly jacked the number up into the NRCan realm. These are the results of the tests:
* Bathing** Bath 21-42 gal, or** Shower 20 gal/d (2 @ 10 gal)
* Toilet 10 gal/d (8 @ 1.6 gal)
* Dish washing 4 gal/d (4 @ 1 gal)
* Laundry 2 gal/d (pro-rated from 14 gal/week)
* Hand washing 2 gal/d (4 @ o0.5 gal)
* Drinking 1 gal/d (mostly Twinings Earl Grey tea)
* Cooking 0.25 gal/d
* Household cleansing 0.25 gal/d
Water The drinking consumption can be reduced using (descending order) water-efficient shower heads, toilets, dishwashers, clothes washers, and automatically closing tapsmight surprise you. LowFor years -flow shower heads alone can reduce water usage by 30%- [http://www. Older shower heads deliver 4 to 5 gallons (15onemedical.1 to 18.9 litres) of com/blog/live-well/daily-water per minute. However-intake/ well, since 1945!] -- the USA Energy Policy Act health community has been erroneously fixated on eight 8-ounce glasses of 1992 sets maximum pure water flow rates at 2.5 gallons (9.5 litres) per minute at a standard residential water pressure of 80 pounds per square inch (552 kilopascals)day.
Before doing the above test, I had settled on 25 galThe [http:/person/day as a design goaliom. Afterwardsnationalacademies.org/ Institute of Medicine], and because water capacity is so critical which was responsible for the 1945 study, now liberally recommends a livetotal daily water intake of 3.7 liters (0.97 gal), from all sources including water, wine, beer, coffee, tea, soda. == Reduce Consumption ==  Water consumption can be reduced using (descending order) water-aboardefficient shower heads, I increased this to 60 gal/person per day overalltoilets, dishwashers, clothes washers, and automatically closing taps. With a 250Low-gal flow shower heads alone can reduce water tank, Sharina would have a base cruising capacity usage by 30%. Older shower heads deliver 4 to 5 gallons (15.1 to 18.9 litres) of two days for two peoplewater per minute. A 500-gal tank would provide The [http://www3.epa.gov/ USA Environmental Protetion] Agency <i>WaterSense</i> lavatory faucet specification sets the same for four peoplemaximum flow rate of lavatory faucets and faucet accessories at 1. A watermaker would have to supplement this for extended cruises5 gallons per minute (gpm) tested at a flowing pressure of 60 pounds per square inch (psi) (common water pressure in most households).<ref>http://www3.epa.gov/watersense/pubs/faq_bs.html</ref> == Tank Overflow ==
The fresh water tank should have an overflow outlet overboard. Boats have been sunk at the dock when connected to shore water that overflowed the tank in one way or another.
 
== Conclusion ==
 
Before doing the above test, I had settled on 25 gal/person/day as a design goal. Afterwards, and because water capacity is so critical for a live-aboard, I increased this to 60 gal/person per day overall. With a 250-gal water tank, this gives a base cruising capacity of two days for two people. A 500-gal tank would provide the same for four people. A [[Watermakers|watermaker]] would have to supplement this for extended cruises.
 
[[Category:FreshwaterSystems]]