Archive for Downsizer For an ethical approach to consumption
 


       Downsizer Forum Index -> Energy Efficiency and Construction/Major Projects
Behemoth

Boiling Water on Tap

Has anybody any comment about these as opposed to a kettle:

http://www.zipheaters.co.uk/pdfs/Specsheets/Zip%20HydroTap%20boiling.pdf

Cheers
jema

We're using a Tefal thingy which is similar, but with or without a filter the water is coming out scummy Sad
mark

they are all the rsge in the yuppy flats these days
the posh ones provide, iced filtered and boiling water.

and they all cost a lot lot more than a kettle - and take a lot more efort to fix if they stop working!

i was talking to a group of plumbers the other day - they told me there is a lot of profit and good money to be made in fitting them!

mark
RichardW

What about the running costs of keeping 16 cups of water hot 24 7?


Justme
dougal

Its throwing technology at the wrong problem.

You've got a mini-Aga, but electric, keeping some water hot all the time...
... bet it tastes lovely when you drink it. Rolling Eyes Quite apart from the cost of running the bloody thing.
Has impatience really determined that the time to heat a kettle is too precious to be "wasted by waiting".

Quite apart from any safety considerations... (there is often a safety cold water blending valve installed *specifically* to limit the temperature of tapwater).

Tea does taste better with freshly boiled (still oxygenated) water.
And coffee (real or instant) does taste better when made with water distinctly below boiling point.

So, my personal verdict: expensive, energy-wasting, and highly unlikely to perform well. An artificial convenience. Your mileage may vary.
bluebell

bit of a 'gadget!'

Good old kettle for me..eco kettle
Blue Sky

We use the hot water from the hot tap in the kitchen for cooking. It is a sealed system on mains pressure and so far it hasn't done us any harm. I also fill the kettle from the hot tap to save gas.

Someone will come along and tell me this is really really bad now. Watch
jema

Are you sure they keep the water hot? The Tefal boils (well gets the water very hot) on the fly.
dougal

jema wrote:
Are you sure they keep the water hot? The Tefal boils (well gets the water very hot) on the fly.

Certain.
See the brochure B linked in the first post
Quote:
No more time wasted waiting for water
to boil

Big selling point.


Unfortunately.
Behemoth

My impression was that it was a turbo boiler that produced 'on demand' boiling water, not a tank of boiling water on standby.

Currently our office kitchen has one of those boilers that has a permanent supply of stored biling water but the suppliers of these thingies were in the building to have their product assesed. I wasn't there to find out what it actually did.

Need to dig some more......
Behemoth

"No more time wasted waiting for water
to boil"

e.g. the water is there 'on demand' but is it boiled on the fly or is it stored?

"No more energy wasted boiling kettles or urns"

I take this to mean it only boils the amount of water you want, not a kettle full for one cup (as some do), or does it....
jema

The brochure implies to me that it boils on the fly, "no more urns"!
mark

jema wrote:
The brochure implies to me that it boils on the fly, "no more urns"!


they don't heat completely on the fly like combi-boilers - they are only rated at about 2KW so couldn't possibly do that.

they keep a small amount of hot water and guard its usage

they safe energy by controling how much water you are heating (most people are very wasteful in how they use kettles and urns). The dispense water in predetermined amounts and you can't accidentally leave the switched on .

I think are a bit like an "underground slightly more techy version" of those quick boilers we used to have above sinks. But that don't sound to trendy as an aqua tap!

mark

I think they have a sleep mode so they can reduce the temperature to something that won't boil but is stil hot and sterile when you don't use them for two or 3 hours - they then take a bit longer for the first use after that.
Behemoth

I've asked them - but having looked at the installation manual I think you are barking up the right tree.
Northern_Lad

Simon wrote:
We use the hot water from the hot tap in the kitchen for cooking. It is a sealed system on mains pressure and so far it hasn't done us any harm. I also fill the kettle from the hot tap to save gas.


That's really bad.
dougal

Behemoth wrote:
My impression was that it was a turbo boiler that produced 'on demand' boiling water, not a tank of boiling water on standby.

Look at the specifications at the top of the second page of the pdf brochure.

It lists that its "Delivery" capacity is 16 "cups at a time", with a "Recovery" capacity of 80 cups per hour. (And this "Recovery" rate is dependant on inlet water and abient air temperatures.)
Which says to me that *something* is being kept hot all the time, and has cooled off after about 16 cups have been drawn off.
That's the meaning of "recovery" - heating up again.
What do the LEDs indicate? My bet is that one of them signifies "up to temperature or not".
There would be no need for such a "recovery" specification if the water was being entirely heated "on demand" by energy being consumed purely as the water was running. If that were the case it could produce a continuous stream of boiling water... and that spec says it can't.

So its storing heat.
Behemoth

It's an urn!
dougal

Behemoth wrote:
It's an urn!

A Little Ern!
mark

Northern_Lad wrote:
Simon wrote:
We use the hot water from the hot tap in the kitchen for cooking. It is a sealed system on mains pressure and so far it hasn't done us any harm. I also fill the kettle from the hot tap to save gas.


That's really bad.


yeah it is is! There is so much gunk in hot water systems! You get a lot of corrosion even in sealed systems and metal leeching out - in particular copper can build up. I think the requirement to use lead free solder only applies to drinking water so can't be guarantted in you hot water system though it is likely the plumber will have used it!

But depending on the temperature of your water you can also get bacteria build up in warm water - in the nice warm soup of debris that end up in hot water systems.

However i agree if you are boiling it the main worry is metals - in particualar if you have a baby or child don't use any water boiled in this way as they are much more susceptible to the build up of metals than an adult.
if you ever looked in a cold water storage tank - you'd probably be reluctant to use your cold bathroom tap for drinking too - most I have looked into are totally gross!! (and of course by the time the water has stood there a bit is is declorinated so again bacteria can breed in the soup at the bottom of your tank!
Behemoth

From the horse's mouth:

"Thank you for your enquiry relating to the 'Zip' Hydrotap, Hydrotap has a boiling water storage capacity ranging from 2.7 litres to 4 litres depending on the model choice, filtered boiling water is dispensed instantly at a flow rate of 3 litres per minute and has a boiling recovery rate between 80 -110 cups per hour, again depending on the model selection."
nats

This is the Tefal thing - it's a very fast kettle by the looks of the thing

http://www.tefal.co.uk/tefal/products/product/index.asp?category%5Fid=400&dept%5Fid=430&sku=U00444&mscssid=CLLD9MRJ2HPS8HNT9LRT1H2XXUHT0EB5
JB

It also doesn't work;

Warning - calculations ahead

To raise 1ml of water 1 degree C requires 1 calorie
1 calorie = 4.2 Joule (ish!)
1 watt = 1 J/s
so to heat a cup of water from 20 degrees to 90 degrees requires

250 ml * 70 calorie/ml * 4 J/calorie ~ 70 000 Joules

To do that in three seconds

70 kJ / 3 s ~ 23.3 Kw !

Or the other way around to do that with a three Kw supply would require about 23 seconds.

Their description is careful to say that it will deliver hot water in three seconds not that it will deliver a full cup in three seconds. What it does instead is heat the water on it's way to pouring it out at a slow rate.

They also claim that it uses only one third of the power of a conventional kettle, but that's only because it only heats the amount of water required. You could of course make the same saving with a cheaper conventional kettle by only filling it one third full.
       Downsizer Forum Index -> Energy Efficiency and Construction/Major Projects
Page 1 of 1
Home Home Home Home Home