Spectra Watermakers

[BlueSovereign]

Originally Posted by Tellie

Roasted, boiled or goobers?

I did look at their site. I didn't mean to suggest they were garage built. I meant that the energy difference to run them is similar to most other brands of watermakers. On some boats energy is not an issue. But on sailboats in particular the energy to run one becomes an issue and the cost of the unit to energy cost savings becomes very important and making a decision on price is not always the best approach. You may save some money up front, but the extra required energy reproducing capabilities of your boat may far out cost that savings.

Are you saying that a Spectra is a more efficient watermaker than most? If so I'd be interested in how one goes about determining that.

My initial reaction earlier was based on having to buy costly so-called "proprietary usuables" which would already add to the cost of one of the more costly water-makers on the market.

Based on various conversations I've had, I might be forgiven for thinking, all things being equal (i.e. you do the required maintaining regardless of manufacture) the primary factor would be reliability.

From the word of mouth information I've had (which of course is not stastically valid), Spectra's are no better than any other water-maker.

Yes, it offers some neat self-maintaining features, however you pay dearly for them, and of course they result in a more complex piece of equipment which statistically would result in a higher probability for failures.

Would value your thoughts on the above.

William

[senormechanico]

My Spectra 180 uses 8 amps to produce 180 gpd or about 6.5 gph. (and it's easier on the ears than my previous units...)

My old PowerSurvivor used 4 amps to produce 35 gpd, or about 1.46 gph.
My old PowerSurvivor 80 used 8 amps to produce 80 gpd or about 3.33 gph.

If you divide the watts consumed (volts x amps) by the gpd, you will get a good idea of the efficiency of each unit.

Steve B.
PS I love my Spectra

[BlueSovereign]

amps or amp-hrs???

and wouldn't the above be relevant depending on whether you have an AC or DC system???

I'm asking the above because I don't know the answers....

[senormechanico]

Watts consumed per gallon produced is the bottom line.

Steve B.

[Tellie]

Originally Posted by BlueSovereign

Are you saying that a Spectra is a more efficient watermaker than most? If so I'd be interested in how one goes about determining that.

My initial reaction earlier was based on having to buy costly so-called "proprietary usuables" which would already add to the cost of one of the more costly water-makers on the market.

Based on various conversations I've had, I might be forgiven for thinking, all things being equal (i.e. you do the required maintaining regardless of manufacture) the primary factor would be reliability.

From the word of mouth information I've had (which of course is not stastically valid), Spectra's are no better than any other water-maker.

Yes, it offers some neat self-maintaining features, however you pay dearly for them, and of course they result in a more complex piece of equipment which statistically would result in a higher probability for failures.

Would value your thoughts on the above.

William

Yes I'm saying that not only is Spectra a more efficient watermaker than most, but more than the rest. Reverse Osmosis is not rocket science and it is accomplished the same way by all marine RO systems by water flow and water pressure. The difference is how the flow and pressure is achieved. Besides Spectra the rest of marine watermaker manufacturers use a high pressure Cat, General, or similar type plunger pump to create the flow and pressure needed to start the RO process. To turn one of these pressure cleaner type pumps to the rpms needed, about 1750rpms, takes a lot of energy and either requires a PTO from your boats engine or a large 1-2hp 12Volt motor or a generator to provide 120-230 volts. Spectra gets around this by using their Clark pump. For all intents and purpose the Clark pump is both a hydraulic intensifier and an energy recovery unit. They use a much smaller feed pump and motor. The smaller more energy efficient feed pump supplies the Clark Pump with a much lower head pressure. The Clark pump which has no electrical component then raises the pressure to the 700+ psi needed to start the RO process.
Many watermakers have proprietary parts. Spectra does as well.
The maintenance on watermakers is the key issue with all of them. I find that the vast majority of problems can usually be traced back to the owner not taking the proper care of their machine. Watermakers need a little more attention than many other boat systems do. But it becomes an easy habit if done properly.
Most water makers are about equal in the reliability department. Some of the differences are the energy used as stated or as senormechanico stated another great advantage of a Spectra is it's far more quiet to operate than the others.
As far as the extras, I agree, bells and whistles cost more they always have. But Spectra does have the Ventura 150gpd and the Cape Horn Extreme 330gpd which are fully manual without the electronics. When it comes to who's watermaker is best in reliability, it really becomes a Ford or Chevy thing. But when it comes to energy efficiency Spectra has them all beat hands down.

[Tellie]

Originally Posted by BlueSovereign

amps or amp-hrs???

and wouldn't the above be relevant depending on whether you have an AC or DC system???

I'm asking the above because I don't know the answers....

The easiest way to figure it out is to ask how many amps does it take to make a gallon of water. All watermaker manufacturers will tell you their best case scenario of how many amps it will take for their units to make a gallon of water.

[GordMay]

Originally Posted by senormechanico

Watts consumed per gallon produced is the bottom line.
Steve B.

Actually, it would be Watt-Hours of energy per gallon produced.
Watt-Hours is a unit of energy, whereas Watts is a unit of power.

(Volts x Amps x 1 Hour) ÷ Amount Produced in 1 Hour
= Energy used per Gallon

Assuming that Steve's ystem is 12VDC Nominal, operating at 13V:

His Spectra 180 uses 8 amps to produce 180 gpd or about 7.5 gph
(8A x 1Hr x 13V) ÷ 7.5 gph = 104Watt-Hr ÷ 7.5 Gal.
= 13.866 Watt-Hours per Gallon

His PowerSurvivor used 4 amps to produce 35 gpd, or about 1.46 gph (1.458)
(4 x 1 x 13) ÷ 1.458 = 52 ÷ 1.458
= 35.67 Watt-Hours per Gallon

His PowerSurvivor 80 used 8 amps to produce 80 gpd or about 3.33 gph
(8 x 1 x 13) ÷ 3.333 = 104 ÷ 3.333
= 31.2 Watt-Hours per Gallon

[senormechanico]

Gord,
You're right but after typing basically what you just said including all the same math (on my laptop) I got disgusted because the heat of my hands makes the mouse pad go nutz! It got completely erased twice, so I just went with a basic sentence.

Steve B.

[GordMay]

Steve:
No criticism intended - I was merely expanding upon your excellent point about energy comparisons.

I have a similar problem. My arthritis makes it increasingly difficult to type more than a few words at a time.
I seldom use my laptop’s integral touch pad, having purchased a cheap conventional mouse and pad /w wrist support. It helps.

[surfmachine]

Hi fellas, I am about to run out of biocide for my pur katadyn powersurvivor 40E, I just bought the boat and checked the operation of the water maker, it was ok, then had to fly back home and didn't biocide it. I was away 3 weeks, it's in the tropics, Langkawi. Came back and the prefilter looked dark, opened it and phew, what a stink. so promptly biocided the system after reading up on it.
Question is, can I buy the citric acid at the chemists in Malaysia/Thailand as the bottle is almost empty?The bottle says "100g of art. no. 8013327 and 240g of art. no 8013609" in the jar, use 10g per litre, and mix up 2 litres to pump through to biocide it.
I got some sodium metabisulphate at the local yacht supply, but that is not used by the pur watermaker?
Thanks.
Keith

[tallyhorob]

surf machine
this is a old thread last post before yours was 4/26/09 so you may want to start a new topic and list it with the name of your watersaver and ask the question there.

[NoTies]

The citric acid is for mineral scale and will not affect the biological growth you have surfmachine. For that you need a detergent/akali cleaner such as sodium metasilicate pentahydrate. The sodium metabisulphate is not for cleaning but preserving. Sorry, don't know where you'll find any in Thailand

[surfmachine]

Thanks Pete, that has made it all a bit clearer, I have a large bottle of alkali cleaner, so I will use that, also, I will flush the membrane with fresh water if we are not going to be using the water maker for 3 days or more, to stop the sea water going off. so, best not to use the Na metabisulphate, as it makes chlorine, which harms the pur membranes?
Thanks again Pete.