What Size Watermaker?
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Stuart Miller
Not less than 60 L/hr
We are planning to install a water maker on our Beneteau 461. Advice from cruising sailors throughout the Asia Pacific region (especially those in the tropics) are adament that the unit should produce not less than 60 litres per hour (13 Imperial gals or 16 US gals))
We are planning to install a water maker on our Beneteau 461. Advice from cruising sailors throughout the Asia Pacific region (especially those in the tropics) are adament that the unit should produce not less than 60 litres per hour (13 Imperial gals or 16 US gals))
R
Russ Neibert
Size and Space
To all of you sailors, be you world cruisers, coastal cruisers, or the weekender, day cruisers, I say to you....."size does matter". When "sizing a water maker" for your vessel, there are some key questions to ask yourself. How many people normally will be aboard the vessel? How many hours a day will I be able to, or better yet, will I want to run the water maker? What are my space for installation restrictions, if any? How much fresh water tankage do I have aboard my vessel? Is there a washer onboard? Icemaker? The "size" of the water maker is two-fold, both in capacity (amount of product water output) and in physical size of the unit itself. As for capacity, bigger is always better, because in the overall scheme of things, the unit will become more efficient energy wise, if you can make enough water to supply your daily needs, in a shorter amount of time. For instance, if you need to make/replenish 40 gallons of water a day (about average, for 3 people, being conservative)and you have a unit rated at 150GPD (US gallons per day), or 6.25gph (US gallons per hour), well, you do the math, it will take you nearly 6-1/2 hours to make your daily requirement of water. Whereas, if you have a unit rated at 200GPD/8.3gph, you'll replenish that same amount of required daily water in 4.8 hours. NOW, here's the REAL importance of this. Most people forget that product water output is directly related to both feedwater temperature and salinity content (measured in PPM, parts per million of TDS, total dissolved solids), mainly salt in sea water, however, there are other TDS's in the "mix" as well. At any rate, the temperature is a key factor because throughout the industry, water maker manufacturers' specs. are set at 77^F., in 32,000ppm of feedwater, operating at 800psi. As an example, right here where I am located, in Southern California, USA, the average sea water temperature is about 64^F. This temperature calls for a "temperature correction factor" (every manufacturer should offer a temperature correction chart in their respective equipment's manuals) of 1.30, meaning that your 8.3gph unit (at 77^F.) can be expected to actually produce approximately 6.38gph, in the 64^F. sea water. The colder the water, the less product water output and the warmer the water, the more product water output (to an extent), with salinity content bearing a factor as well, especially on the product water's quality. Most people do not take this into account and the then when they get their 6.5gph unit out in the "real world" are sometimes disappointed in its performance. In addition to the above mentioned factors, most all membrane elements have a +/- 20% factor on their performance, which is partially based on the feed water temperature, TDS of the the feed water and yes, even the membrane material and construction itself. This is the main reason that "bigger is generally better", as far as output capacity of the unit. As for the physical size of the unit and installation onboard a particular vessel, you'll need to ask if a unit is available as a modular (separate components, in smaller mounting foots), versus one complete frame unit, which may not fit in any "one spot" onboard your boat. Or, perhaps semi-modular, with most of the "core" of the unit within a frame and some of the smaller components outside the frame, with the ability to be spread around in the boat a little bit, where one large frame may not fit. This is something that must be addressed case by case, with each individual application, however, suffice it to say, if the manufacturer has all of these various configurations available, with the same features across the board in the line, then it may be telling you that the manufacturer has been around long enough to know there are certainly many different applications and that they are "invested in the market enough" to address all possibilities. I highly suggest to all potential water maker purchasers, even "toying with the idea", to contact an industry expert that has experience in the marine industry market, to assist you with making the right choice, for a unit to fulfill your individual needs. Be sure they are listening to you and helping you get what you really need, and not what they want to sell you. To the gentleman with the Catalina 34MKII, I invite you to contact myself, here at the Village Marine Tec factory office, to discuss your needs. I am not quite certain exactly where onboard your Catalina 34 that I'd recommend placing a unit, but I'm sure I can give some direction on what may, or may not work. I personally live about 1-1/2 miles from the Catalina factory and have sold many units to Catalina owners. What year is your Catalina, sir? If you'd like "bump heads" on this topic, please contact me at my office.... rneibert@villagemarine.com
To all of you sailors, be you world cruisers, coastal cruisers, or the weekender, day cruisers, I say to you....."size does matter". When "sizing a water maker" for your vessel, there are some key questions to ask yourself. How many people normally will be aboard the vessel? How many hours a day will I be able to, or better yet, will I want to run the water maker? What are my space for installation restrictions, if any? How much fresh water tankage do I have aboard my vessel? Is there a washer onboard? Icemaker? The "size" of the water maker is two-fold, both in capacity (amount of product water output) and in physical size of the unit itself. As for capacity, bigger is always better, because in the overall scheme of things, the unit will become more efficient energy wise, if you can make enough water to supply your daily needs, in a shorter amount of time. For instance, if you need to make/replenish 40 gallons of water a day (about average, for 3 people, being conservative)and you have a unit rated at 150GPD (US gallons per day), or 6.25gph (US gallons per hour), well, you do the math, it will take you nearly 6-1/2 hours to make your daily requirement of water. Whereas, if you have a unit rated at 200GPD/8.3gph, you'll replenish that same amount of required daily water in 4.8 hours. NOW, here's the REAL importance of this. Most people forget that product water output is directly related to both feedwater temperature and salinity content (measured in PPM, parts per million of TDS, total dissolved solids), mainly salt in sea water, however, there are other TDS's in the "mix" as well. At any rate, the temperature is a key factor because throughout the industry, water maker manufacturers' specs. are set at 77^F., in 32,000ppm of feedwater, operating at 800psi. As an example, right here where I am located, in Southern California, USA, the average sea water temperature is about 64^F. This temperature calls for a "temperature correction factor" (every manufacturer should offer a temperature correction chart in their respective equipment's manuals) of 1.30, meaning that your 8.3gph unit (at 77^F.) can be expected to actually produce approximately 6.38gph, in the 64^F. sea water. The colder the water, the less product water output and the warmer the water, the more product water output (to an extent), with salinity content bearing a factor as well, especially on the product water's quality. Most people do not take this into account and the then when they get their 6.5gph unit out in the "real world" are sometimes disappointed in its performance. In addition to the above mentioned factors, most all membrane elements have a +/- 20% factor on their performance, which is partially based on the feed water temperature, TDS of the the feed water and yes, even the membrane material and construction itself. This is the main reason that "bigger is generally better", as far as output capacity of the unit. As for the physical size of the unit and installation onboard a particular vessel, you'll need to ask if a unit is available as a modular (separate components, in smaller mounting foots), versus one complete frame unit, which may not fit in any "one spot" onboard your boat. Or, perhaps semi-modular, with most of the "core" of the unit within a frame and some of the smaller components outside the frame, with the ability to be spread around in the boat a little bit, where one large frame may not fit. This is something that must be addressed case by case, with each individual application, however, suffice it to say, if the manufacturer has all of these various configurations available, with the same features across the board in the line, then it may be telling you that the manufacturer has been around long enough to know there are certainly many different applications and that they are "invested in the market enough" to address all possibilities. I highly suggest to all potential water maker purchasers, even "toying with the idea", to contact an industry expert that has experience in the marine industry market, to assist you with making the right choice, for a unit to fulfill your individual needs. Be sure they are listening to you and helping you get what you really need, and not what they want to sell you. To the gentleman with the Catalina 34MKII, I invite you to contact myself, here at the Village Marine Tec factory office, to discuss your needs. I am not quite certain exactly where onboard your Catalina 34 that I'd recommend placing a unit, but I'm sure I can give some direction on what may, or may not work. I personally live about 1-1/2 miles from the Catalina factory and have sold many units to Catalina owners. What year is your Catalina, sir? If you'd like "bump heads" on this topic, please contact me at my office.... rneibert@villagemarine.com
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