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Trainman 864

Registered
24 Sep 2015
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50
Glad you raised the rainwater issue again Jimmy, I have worries about this on reflection. Acidity in the rain may not be the best thing to introduce to live steam. For my part I reckon having expended near or in many cases well over a grand UK for a live steam engine getting the right water should be a priority. A dehumidifier is really the only option to be sure, chemists so called de humidified has doubtful properties and certainly any tapwater may have chalk or other chemicals to keep it drinkable even in a soft water area.
Just to add my 2d worth - without trying to prolong the controversy ....

Distilled water - changes it's ph from the moment it's made by the adsorption of CO2 if exposed to the atmosphere.

Dehumidifier water - needs filtration and can be acidic.

Rainwater - needs filtration and can be acidic, especially if the wind has been blowing from the industrial areas of N. europe.

Tumble dryer - can have lint - needs filtration.

Tap water - even soft water can cause eventual scaling.

Fridge water - needs filtration.

Sea water - causes dezincification and scaling - (just kidding .... :))

So that leaves - with the best balance of pros and cons and convienience ....

Deionized water - with 5% tap water added to quench it's insatiable desire to claw back it's lost ions.
 
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dunnyrail

DOGS, Garden Railways, Steam Trains, Jive Dancing,
25 Oct 2009
19,666
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St.Neots Cambridgeshire UK
Just to add my 2d worth - without trying to prolong the controversy ....

Distilled water - changes it's ph from the moment it's made by the adsorption of CO2 if exposed to the atmosphere.

Dehumidifier water - needs filtration and can be acidic.

Rainwater - needs filtration and can be acidic, especially if the wind has been blowing from the industrial areas of N. europe.

Tumble dryer - can have lint - needs filtration.

Tap water - even soft water can cause eventual scaling.

Fridge water - needs filtration.

Sea water - causes dezincification and scaling - (just kidding .... :))

So that leaves - with the best balance of pros and cons and convienience ....

Deionized water - with 5% tap water added to quench it's insatiable desire to claw back it's lost ions.
Ok interesting, but can you say why water from a Dehumidifier needs to be filtered please?
 

Trainman 864

Registered
24 Sep 2015
270
50
Ok interesting, but can you say why water from a Dehumidifier needs to be filtered please?

OK - I should have said - 'may need to be filtered' .... :)

Most dehumidifiers of either the refridgeration or adsorbtion/absorbtion type have a relatively coarse filter on the air inlet to reduce the risk of obstructing the air passages within the device. There is no need for a fine filter as most of the airborne dust (including pathogens and allergens) will be entrained in the water condensing on the refigerant evaporator in a refrigerant dehumidifier - and on the water condenser in a desicant drum dehumidifier.

These contaminants in the water are of no consequence if you are using the device as a dehumidifier, in fact their removal has the benefit of improving the quality of the dried air - but if you want to use the waste water then you might want to consider filtering it.

The reality is of course, in most domestic applications, the contamination of the waste water is so low as to not be worth worrying about when using it for boiler feed water.
 
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Paul M

Registered
25 Oct 2016
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Royston
These contaminants in the water are of no consequence if you are using the device as a dehumidifier, in fact their removal has the benefit of improving the quality of the dried air - but if you want to use the waste water then you might want to consider filtering it.
For the sake of an extra few minutes and a coffee filter, it's probably worth it
 

Fred2179G

Registered
20 Apr 2017
601
133
USA
So that leaves - with the best balance of pros and cons and convienience ....

Deionized water - with 5% tap water added to quench it's insatiable desire to claw back it's lost ions.
Well, over this side of the pond we can get "steam distilled water" in (US) gallon jugs for $1 in the local supermarket. Can't beat that for convenience. (Why don't they sell them in the UK? The water is used for steam irons, etc.)
 

JimmyB

Semi-Retired; more time for trains.
Just to add my 2d worth - without trying to prolong the controversy ....

Distilled water - changes it's ph from the moment it's made by the adsorption of CO2 if exposed to the atmosphere.

Dehumidifier water - needs filtration and can be acidic.

Rainwater - needs filtration and can be acidic, especially if the wind has been blowing from the industrial areas of N. europe.

Tumble dryer - can have lint - needs filtration.

Tap water - even soft water can cause eventual scaling.

Fridge water - needs filtration.

Sea water - causes dezincification and scaling - (just kidding .... :))

So that leaves - with the best balance of pros and cons and convienience ....

Deionized water - with 5% tap water added to quench it's insatiable desire to claw back it's lost ions.
First, I always filter my water what ever the source. Second deionised water I was told is a big No No, as the chemistry causes the ionisation in the vessel to deionise to match the contents eventually weakening the structure.