Just to give you an idea of heat, I have the RO Membrane assembly on THIRD DAY mounted in my engine compartment.  When I take temperature readings with my infrared heat gun of the RO Membrane surface (I love that heat gun by the way for $20 from Harbor Freight) I've never seen my membrane housing temperature above the temperature limits.  So it would be hard for me to believe that the heat from the electric motor could elevate and heat soak your locker space more than my 120Hp Ford Lehman during a 24hr run in the Sea of Cortez.  It has been a long time since my collage physics class, but the heat generated by the electric motor should be able to be dispersed and not over-temp your RO Membranes.  However, we had a client who mounted his pump and motor assembly in a locker below his quarter berth with no ventilation.  The locker size was 23"W x 11"H x 100" deep (25,300 cubic inches).  He found that after 1.5hrs of running his unit the thermal overload on his 1.0Hp motor would trip and shut down.  He was able to solve the problem of inadequate air ventilation by making some holes in the locker and installing a small 12v computer fan to pull cool fresh air into the locker space.  For reference, the boost pump motor casing temp runs about 130F, the high pressure pump runs 165F, and the 1.0Hp electric motor runs 165-190F, depending on where on the motor you take your reading.

Are you pushing the membranes too hard by achieving such a large fresh water output?  I’ve heard that you should not exceed a 13% conversion from sea water to fresh drinking water?

Answer:
If you will be running your watermaker 24 hours per day for 365 days per year, then there is a good possibility that the membrane life will not reach the 3+ years of continuous duty which is expected for a well-cared for DOW Filmtec membrane.  However, the non-continuous operating characteristics of a marine watermaker aboard a cruising vessel, provides us the opportunity to increase our fresh water production while still keeping a cost-benefit eye on membrane life
 
A continuous duty RO membrane would have 26,280 hours of operation after three years of service.  By comparison a heavily used watermaker aboard a cruising boat, ran for two hours every day (that’s 40 gals of water with a SeaMaker 20 or 60 gals with a SeaMaker 30) would only have 2136 hours of operation after the same three year period.  The down-side of operating a RO membrane above the 13% sea water to fresh water conversion rate is simply a need for more frequent cleaning of the membrane to remove scale deposits, which can decrease the fresh water production flow rate.  However, when compared with the up-side of producing 20 gallons of drinking water per hour rather than 12, as would be the case if we remained under the 13% value.  The increased production simply outweighs the downside when you look at the ease and cost of membrane cleaning.

Perhaps you have heard that cleaning a RO membrane is hard?  Well, it can be, but then there is our way.  You simply remove your 5 micron system pre-filter element and replace it with a cleaning cartridge and then flush your system with fresh water, as you would during a normal post system run back flush.  The cartridges are inexpensive ($20ea) and don’t require any mixing of chemicals, just plug in the cleaning cartridge run the back flush, and any scale deposits will be removed restoring your membrane’s freshwater production rate.

Perhaps you have also heard that the process of RO membrane cleaning is hard on the RO membrane and frequent cleaning will result in premature death of the membrane?  You can’t beat the laws of physics, but you can play them to your benefit if you understand the technical issues at play.  In an ideal world, you would never subject your RO membrane to anything other than clean pure sea water.  In the real world, however, RO membranes are cleaned.   The question for us to understand is then how much cleaning is bad for membrane life.  DOW’s recommendations cleaning a continuous duty RO membrane every 2190 hours of operation or 4 times per year.  It would take a lot of time to reach those levels of RO membrane cleaning on a cruising boat.  Simply put, your RO membrane will not fail due to an increase in cleaning to remove scale; it most likely will be other factors such as improper pickling and storage between use that causes RO membrane failure.

In the end, it all boils down to dollars and cents, so let’s look at the financial issues with running the RO membrane above the 13% ratio.  We know that generator run time equates to fuel costs, so the faster you can top off your water tanks, the faster you can turn off the generator and get back to cruising.  A yearly membrane cleaning for scale will add $20/year in operational costs for a membrane cleaning cartridge.  At $187 for a new RO Membrane it makes sense to view the membrane more as a long term consumable rather than designing the SeaMaker system around a $187 replacement part, that’s available world-wide. 

Question:
How far away from each other can the modules be mounted?

Answer:
The individual modules can be mounted as far apart or as close together on your boat as space dictates (I’m assuming you don’t have a 300ft Mega Yacht and want to spread the Modules from stern to bow).  But a distance of plumbing of 10ft between the modules will not have a negative effect on system performance.  The sea water boost pump is over sized in delivering sea water to the high pressure pump and making sure your high pressure pump gets plenty of flow is the typical bottle neck in systems.  The SeaMaker systems come standard with 30ft of sea water inlet connection tubing, 30ft of brine discharge tubing and 30ft of fresh drinking water tubing, and a 3ft high pressure line to connect high pressure pump to the RO membrane pressure vessel assembly.  Although these amounts should cover most installations, additional lengths of tubing can be supplied.

Question:
Are there any water level, height, or heel angle restrictions?

Answer:
The only restrictions would be that the motor/pump assembly needs to be mounted in a location so that it will NOT get splashed with water, for obvious 120v electrical reasons, and is level when the boat is at rest.  The only heel angle restriction is that the placement of your watermaker through hull needs to be low enough where it doesn’t come out of the water while operating the unit while underway.  Over sizing of the sea water boost pump, takes away the standard concerns or requirements on where you mount your watermaker system components.  Below or above the waterline installations are both perfectly fine.

Question:
Does it require a dedicated through hull for input?

Answer:
No - BUT, by not having it’s own dedicated through hull, you could be asking for trouble.
Here’s a quick list of the potential risks in attempting to share a through hull and it’s our recommendation that the SeaMaker does have a dedicated sea water inlet through hull.

1. The high pressure pump and RO membranes do not like air bubbles (possible damage).  When the system is operating there will be a vacuum at the through hull and any T-fitting so that without the proper hard shut off valve, first water and then air could be sucked into the watermaker intake lines from the other system attached to the through hull. 
2. There is the “risk” of insufficient flow to the inlet of the watermaker if two systems are pulling from the same through hull.
3. The other system now sharing the watermaker through hull may be starved for flow or suck back air through the watermaker plumbing. If T-ed into the engine’s raw water cooling system, for example, this would be bad with obvious problems in overheating the ships main engine.

All of these concerns can be addressed by a proper plumbing installation and with a few extra on/off ball valves, but it will also then add extra complexity to the operation of your watermaker, with extra valves to access and select at start-up and shut down. Some people are ok with this as a trade-off for the extra cost in putting an extra “hole” in the bottom of their boat, but Cruise RO Water’s cruising and design ethos is simplicity, so we would strongly recommend a dedicated through hull for your watermaker. 

Question:
What about waste water?

Answer:
The waste water, or technically brine in RO speak, can be discharged from the boat in a way that you feel the most comfortable with.  A simple above the waterline plastic through hull fitting for discharge overboard is the simplest solution. 

Question:
How many amps does the SeaMaker take?

Answer:
The SeaMaker 20 and 30 are designed to be operated off a Honda EU2000i generator (or similar sized generator or inverter).  The Honda has a peak power load of 16.7 amps and a duty cycle of 13.3 amps at 120v.  Our testing has shown that while operating at a system pressure of 800PSI (which we consider normal operating pressure) the unit will use 13.3 amps to drive the high pressure pump.  The sea water boost pump, however, operates off the boat's 12v system and will use approximately 10.5 amps at 12v, depending on plumbing configuration and sea water inlet line length. 

Question:
How frequently can it/should it be run?

Answer:
The SeaMaker series of watermakers are built using commercial grade parts to commercial standards of construction and can be run every day or as little as a few days per year.   Your water needs will determine the actual run time.  RO systems, like many pieces of equipment, like to be run, but if stored properly can offer intermittent use without damaging the system, particularly, the RO Membranes. 

Let’s look at the most efficient way to operate your watermaker.  At the end of each run, there is a fresh water rinse of the system to inhibit biological growth and allow the wetted surfaces to sit in fresh rather than sea water.  This takes about 2-4 gallons of fresh water (depending on the length of lines in your system).  So if you run your watermaker every day for 1 hour and make 20 gals, you could then use 3 gallons to flush you system, giving you a net water production of 17 gallons per day.  Now let’s say you run for two hours every other day.  You will still use the same quantity of fresh water to flush the system (3 gals) but now you have a net water production of 37 gallon (or for comparison 18.5 gallons per day).  So you can see the small, but measurable, difference in the efficiency of a longer run time every other day compared to a daily run.

Another factor in determining the most efficient run time is that if the system sits unused for more than 3-5 days, you need to do one of two things: Flush through another 2-4 gallons of fresh water or add some preservative to the system for longer term storage.  You can continue this 3-5 day fresh water purge indefinitely rather than adding preservative. 

This issue of back flushing and adding preservative isn’t something special or unique to our systems, but is simply a factor in RO desalination systems from all makers.

Question:
What about membrane preservation and pickling?  How often, how time consuming?

Answer:
If you are not letting the SeaMaker sit unused for more than 5 days, then you should never need to add a preservative to you system, which is known as pickling.  However, if you will not be using the SeaMaker for more than 5 days, the preservative can be added to the system by mixing the pickling solution in a 5 gallon bucket and then sucking the solution through the system, utilizing the supplied three-way pickling valve.  Alternatively, rather than mixing the preservative solution, we offer pickling cartridges that make the process as easy as performing a standard post system run back wash.  To pickle with a cartridge, you simply remove the 20 micron pre-filter element, replace it with the cartridge, and perform a system flush.  The entire pickling process should take no more than 5 minutes.

Question:
How easy is it to operate?

Answer:
Here’s a brief look at the basic start-up, operation, and shut down procedure, which will all be detailed in the operation and maintenance manual.  I’ll do this in bullet point format, but I think it will give you a pretty good idea of the simplicity.

Start-up:
1. Turn on the sea water boost pump and let run for 1 minute to push fresh sea water into the system and purge out any old water and preservative along with air bubbles.
2. Turn on the high pressure pump and let run for 1 min 
3. Slowly turn the pressure regulating valve clockwise until the pressure gauge reads 800PSI
4. Sample the fresh water from tank
5. Turn the product water selector valve to send the product water to the water tank rather than the sample port.

Operation:
1. Periodically monitor the system PSI and product water output for the desired run time

Shut down:
1. Turn the product water selector valve back to sample (away from tank)
2. Slowly turn the pressure regulating valve counterclockwise to lower pressure from the system as indicated on the pressure gauge
3. Turn off the high pressure pump
4. Turn the feed water select valve to pull fresh water from tank (or bucket if desired) to begin system black flushing
5. Turn the high pressure pump back on but DO NOT turn the pressure regulating valve to put the system under pressure.  Run the system like this for the required length of time so that fresh water is exiting the brine (once you measure this time, you will know how long based on your systems plumbing length)
6. Turn off high pressure pump
7. Turn off boost pump

Question:
What about water testing?

Answer:
We provide (or you can purchase from another source) a hand-held TDS meter, so that you can periodically test the TDS (Total Dissolved Solids) of the product water.  Once you are familiar with the operation of your system and how long it takes for the product water TDS to be acceptable for drinking, testing the TDS isn’t something you need to do every time, but simply test periodically as a way to monitor system performance.