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-   -   Distilled Water : A scam running? (https://www.team-bhp.com/forum/technical-stuff/137162-distilled-water-scam-running-3.html)

I am glad thr OP started thos thread.

Recently an auto parts shop sold us (battery acid and claimed it was) distilled water. I came home and tasted it and realized it was battery acid -- may be the salt peter kind, who knows!.. When I returned it to the shop, he said this what all shops sell as distilled water these days !.

Caveat emptor..!

I wonder if Batter manufacturers, if asked, will recommend brands of distilled water that is safe to use. It should be in their best interest as they are ones who will be affected by warranty claims.

There are descaling powders available, typically for washing machines and even steam irons. They claim to clean the accumulated deposits left by water over an extended use. These deposits are mainly of limestones and other dissolved minerals in water. We can definitely use filetered or just 'clean' water for windshield washing but these would leave deposits in water tanks and the pipeline. Using these descaling powder, say once in 6 months can help us clean those deposits. How much its necessary, that I dont know. Also, I am open to discuss if at all it should be used in a car.

Regarding washer detergents, Maruti sells sachets for exactly that purpose which costs less than Rs. 20 I guess to be added to one tankfull. May be some shampoo can also be used. I would be reluctant to use colin or any other spirit based cleaner on a windshield as it may affect visibility of the glass, esp at night. Colin is mostly like soap water, but I think it has some spirit/ alcohol too.

I would you suggest that you read the contents of a coolant mixture whichever one your car takes. If you cant find one with ingredients on it then there are various techincal sheets for various organic, water or oil based mixtures (thats is the reason for the different colours) that can be downloaded from manufacturers.
All of them in common will be that the heat transfer value or theta will be higher than water.
Moreover most big brands have started changing the name of their coolants to say " antifreeze and summer coolant" because most people make the assumtion that the coolant acts only as an antifreeze by changing the freezing point. Maybe 30-40 years ago this was true however today there are many functions. One of which is thermal conductance and also to change the boiling boil of the fluid which along with the pressurisation can raise the boil off point of your system massively.

Thinking pruerly logically not scientifically let look at these points also:
If you use 100% coolant you will:
Widen the tempurature range at which the coolant will remain liquid - Not a bad thing
Increase the thermal conductivity of the fluid in the system - Not a bad thing
Increase the corrosion inhibitor concentration - Not a bad thing
Remove any pure water molecules in the system - Not a bad thing (if you have an iron block)
Increase the viscositity of the fluid - Not a bad thing (it increases the fuel pump effieciency)

The bad part is that it is not strickly "nessesary" and can be at least twice as expensive as most concerations sold off the shelf tend to need a 2:1 or 3:1 mix. But if you can squeeze maybe an extra 5%-8% extra heat removal effeciency without any modification then why not?

You are wrong my friend ->
100% coolant will result in a higher temperature. 100% water results in lower temps but 100% water will corrode the radiator and the insides of the engine. That's why we use coolant.
For Indian/Tropical climates Antifreeze is not needed at all!

Remember coolant is a chemical modifier which has poor heat transfer properties. It functions to change the boiling and freezing points of water along with this it provides some protection to the metal parts/water pump.

Also Remember water transfers heat the fastest.

For starters, let us assume that there is a necessity for greater efficiency (I doubt it- my Ikon never crosses the half mark. I have not driven it in a desert though).

Heat transfer efficiency in an automotive cooling system would be dependent on-
1. Specific Heat Capacity of the coolant. (Higher is better)
2. Flow Rate of the coolant. (Higher is better- to a point.)
3. Ability to radiate heat (Radiator design, air flow, etc.)

Now, changing the coolant affects the first two. I'll tackle the first one last. It is obvious that pure coolant is thicker, and hence has a lower flow rate. Therefore, it is probably not as efficient. Even otherwise, it stresses the water pump. And no, it has nothing to do with the fuel pump.

Point 1- Specific Heat Capacity is different from thermal conductivity. The former is the amount of energy required to change the temperature, while the latter is ability of the material to transfer heat.
In case of water, it will undergo a phase change at 100 degrees C. (At MSL with 1 ATM) to steam. The coolant additive prevents this from happening. It allows the water to keep absorbing more heat, and therefore increases the specific heat capacity. This is a chemical process. The additive itself does not absorb the extra heat. The specific heat capacity of the coolant itself is much lower. But it ALLOWS the water to absorb more.

Something, although not strictly analogous, would be this- if a bit of dish soap in water cleans the dishes well, using ONLY dish soap should better, right? Nope. The combination outperforms either. Similarly, Water+Additive outperforms either on its own.

I hope that has made things clearer.

P.S. You might want to look up how it also prevents corrosion.

I have a similar machine, don't know the price cause it came bundled along with the autoclave. I use it regularly for the autoclave. Last week a colleague happened to tell me he has stopped using his machine because it consumes too much electricity, and buying distilled water at a fuel station at Rs 30 / 5 Lts is much cheaper. Got to verify whether its chemical distilled water or evaporation technology.

When do I come with a five litre jar ? :uncontrol I need some too for my cars.

Dear Chris,

I have been using a water/ coolant mixture and have driven in hot summers for now 11 years in my car. Not once I have seen my temperature needle going up more than half the mark. IMO, this should be conclusive enough for me to believe that a mixture works best.

And 'thermal conductance' was always the primary function of coolant based systems. Your post suggests that its a 'newly added feature'- No.

Before I could reply to your post, a few members have put up a precise reply and the example of soap and water was fantastic.

If you are still not convinced, then a whole lot of discussion has happened here. http://www.team-bhp.com/forum/techni...0-coolant.html
Someone has also conducted this experiment and compared the results too. Please give some time to it.

My heartfelt thanks to all for their replies. I had not expected as many replies.

MY CONCLUSION:

My doubts are clear. It is highly probable that there is a scam running. It is better to buy lab grade/quality DW from a reliable source. That should rule out petrol pumps: they can make oil and water mix, and put to shame the best of chemists.

Now for the rest of it: coolants come in premixed and concentrate forms. It is the fine print on the label that probably eludes us. My FIAT needs a concentrate, to be diluted before use. Similarly for the windscreen. Tutela concentrate diluted...I use the MGP sachet, though. 15 bucks.

Now if it is indeed saltpetred water, in the guise of DW I have already screwed up a lot many things. FLUSH TIME! So much for being "by the book". :Frustrati

I dilute my Optimum No Rinse wash and shine in the same water, for Quick Detailer use, so the paint might be a gonner too, sooner or later. Will definitely shift to lab grade.

The planted aquarium : survives though!

But somebody mentioned tasting it for testing it: hats off, the definitive test indeed!

Isn't distilled water mildly corrosive?

AFAIK you should fill
1> soft water mixed with coolant in the radiator.
2> soft water mixed with a surfactant in the Wiper washer reservoir
3> distilled water in the battery when required.

Since distilled water has no dissolved gasses, minerals and salts it will dissolve trace amounts of metal and rubber [not sure about this] and hence could damage the cooling mechanism, piping and wipers in due course.

Mixing a surfactant in the water will prevent it from leaving stains when it evapourates. I think the wiper water mixtures that you get are detergents that have surfactants in them.

http://en.wikipedia.org/wiki/Surfactant

If it is chemically distilled via RO technology it should be purer than if it is distilled is evapouration [unless the condensation happens in an evacuated chamber]

Incorrect. Neither RO nor distillation effectively removes chlorine compounds used to keep the water microbe free. However, most RO units have carbon filters to remove it, and you can bet lab-grade distilled water has also passed through a carbon filter before being distilled (Also, it is a multi-step fractional distillation process). That being said, even if you use water you have distilled yourself (Takes less than Rs. 500 worth of supplies- a tea kettle and a pan), which will have trace chlorine, it should be fine. The other dissolved impurities that harm the battery will have been removed, this water is around 99.9% pure.

Also, if you are referring to home filtration RO units, some of them put the "right" amount of mineral back into the water, using mineral cartridges. This is in an effort to prevent desalination of the body/leeching of salts. You might as well go with tap water in that case.

So distillation via evapouration is better?

Distillation IS evaporation and condensation. RO-treated water is similar chemically, but NOT vaporised and condensed. But I get the gist- yes, when you don't know how the RO treatment is carried out, go for the distilled (lab grade).

Essentially, both are methods to purify water.

That I know, but if RO and evap-condensation give the same result [pure water without and dissolved gasses, salts and minerals] isn't it the same thing?

If the result is the same then does it really matter?

My thinking when i made my origin post was that it would probably be easier to get purer water using RO filteration than distillation.

Am i right?

Yes and no. In theory, both should give acceptable results. But if you don't know how the water was RO purified (ie if it was done for drinking purposes, with added mineral content) then it is better to go with distilled.